GPA 2140 - Liquefied Petroleum Gas Specifications and Test Methods

S T D - G P A S T D 2140-ENGL 1777

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GPA Standard 2140-97

Liquefied Petroleum Gas Specifications and Test Methods r-

Adopted as Recommended Procedures 1931 Revised 1940-1947-1948-1951-1955-1957-1959-1960-1962-1968 1970-7973-1975-1977-7980- 7984-1986- 7988-1990-1992-1996-1997

Gas ProcessorsAssociatlon 6526 East 60th Street

Tulsa, Oklahoma 74145

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Copyright Gas Processors Association Provided by IHS under license with GPA No reproduction or networking permitted without license from IHS

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TABLE OF CONTENTS

Disclaimer ........................................................................................

ii

Foreword .........................................................................................

ii

GPA Specificationsfor Liquefied Petroleum Gases .......................................................

1

ASTM D-1265-92: Sampling Liquefied Petroleum Gases .................................................

.2

..........................................

.5

ASTM D-1657-89: Density or Relative Density of Light Hydrocarbons by PressureHydrometer ............................................................

10

ASTM D-1267-95: Vapor Pressure of Liquefied Petroleum Gases

...............................................

14

ASTM D-1838-91: Copper Strip Corrosion by Liquefied Petroleum Gases ..................................................................

17

ASTM D-2158-92: Residues in Liquefied Petroleum Gases. ..............................................

.20

ASTM D-1837-94: Volatility of Liquefied Petroleum Gases

ASTM D-2163-91: Analysis of Liquefied Petroleum (LP) Gases and

...................................... ASTM D-2713-91: Dryness of Propane (Valve Freeze Method). ........................................... Propylene Concentrates by Gas Chromatography.

ASTM D-2784-92: Sulfur in Liquefied Petroleum Gases (Oxyhydrogen Burner or Lamp). .................................................... GPA 2174-93:

Obtaining Liquid Hydrocarbon Samples Using a Floating Pistoncylinder ...................................................................

Propane Dryness Test (Cobalt Bromide Method). ......................................................

Note:

.24 .29 .31

37 .50

ASTM test methods included in this publication have been adopted by GPA, and are included through a right-to-reprint agreement with, and by special permission of, the American Society of Testing and Materials, 1916 Race Street, Philadelphia, Pa.

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1


DISCLAIMER GPA publications necessarily address problems of a general nature and may be used by anyone desiring to do so. Every effort has been made by GPA to assure accuracy and reliability of the information contained in its publications. With respect to particular circumstances, local, state, and federal laws and regulations should be reviewed. It is not the intent of GPA to assume the duties of employers, manufacturers, or suppliers to warn and properly train employees, or others exposed, concerning health and safety risks or precautions. GPA makes no representation, warranty, or guarantee in connection with this publication and hereby expressly disclaims any liability or responsibility for loss or damage resulting ffom its use or for the violation of any federal, state, or municipal regulation with which this publication may conflict, or for any infringement of letters of patent regarding apparatus, equipment, or method so covered.

FOREWORD

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These specifications generally define physical properties and characteristics of liquefied petroleum gases (LP-Gas) which make them suitable for private, commercial, or industrial applications. These specifications do not purport to specifically define all possible requirements to meet all possible applications. Therefore the user is cautioned to exercise judgement informulating final specijications for specific applications. The Gas Processors Association, its management, and supporting companies claim no specific knowledge of how manufacturers and users will produce, handle, store, transfer or consume the products defined herein and therefore, are not responsible for any claims, causes of action, liabilities, losses or expenses resulting from injury or death of persons and/or damage to property arising directly or indirectly from the use of LP-Gas or these specifications relating to LP-Gas. LP-gases are composed of hydrocarbon compounds, predominately propane and butane, produced during the processing of natural gas and also in the conventional processing of crude oil. The composition of LP-gases may vary depending on the source and the ratios of propane and butane content. They exist as gases at atmospheric pressure and ambient temperatures, but are readily liquefied under moderate pressures for transportation and utilization There are many uses for LP-gases, the major ones being as (1) petrochemical, synthetic rubber, and motor gasoline feedstocks, and as (2) commercial, domestic and industrial fuel. The following may be accepted as a general guide for the common uses for the four fuel types covered by these specifications: Commercial Propane is the preferred fuel type for domestic, commercial and industrial fuels. It is also a suitable fuel for low severity internal combustion engines. Commercial Butane is used principally as feedstock for petrochemicals, synthetic rubber, and as blending stocks or feedstocks in the manufacture of motor gasolines. Its use as a fuel is generally limited to industrial applications where vaporization problems are not encountered; however, small quantities are used as domestic fuel. Commercial Butane-Propane Mixtures cover a broad range of mixtures, which permits the tailoring of fuels or feedstocks to specific needs. Propane HD-5 is less variable in composition and combustion characteristics than other products covered by these specifications. It is also suitable as a fuel for internal combustion engines operating at moderate to high engine severity.

Additional Considerations Odorization For certain applications including, but not limited to, use of LP-gas for residential and commercial fuels, users of LPgas should be aware of additional requirements of other standards, principally NFPA 58 "Storage and Handling of Liquefied Petroleum Gases"(1) and other regulations (2). NFPA 58 has been adopted widely by local, state and other regulatory bodies in the form of laws, ordinances, or regulations governing the safe storage, transportation, and use of LP-gas as fuels. Among other requirements, NFPA 58 (Sec. 14.1.1) stipulates that LP-gases "be odorized by the addition of a warning agent of such character that they are detectable, by a distinct odor, down to a concentration in air of not over one-fifth the lower limit of flammability". NFPA notes that "ethyl mercaptan in the ratio of 1.0 Ib. per 10,OOO gallon of liquid LP-Gas has been recognized as an effective odorant. Other odorants and quantities meeting the requirements of 1-4.1.1 may be used. Research on odorants has shown that thiophane in a ratio of at least 6.4 lbs. per 10,OOO gallon of liquid LP-Gas may satisfy the requirements of 1-4.1.". Ammonia NFPA 58 also states that LP-gas stored or used in systems within the scope of this standard "shall not contain ammonia". Although ammonia is not a naturally occurring contaminant of LP-gas, certain industry practices, including the dual use of transportation or storage equipment, may inadvertently result in contamination of LP-gas by ammonia. When such a possibility exists, users should test for the presence of ammonia in propane and take appropriate means to eliminate ammonia from the system, since such contamination may cause stress corrosion cracking of copper bearing alloys in the distribution system. 11 Copyright Gas Processors Association Provided by IHS under license with GPA No reproduction or networking permitted without license from IHS


S T D - G P A S T D 21'4O-ENGL

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Fluorides

Sulfur Compounds Sulfur compounds such as elemental sulfur, hydrogen sulfide, and carbonyl sulfide may be naturally occurring contaminates of natural gas from which LP-gas is derived. The Copper Snip Corrosion Test (ASTM D-1838) and the Total Sulfur Test (ASTM D-2784) assure limitation of objectionable sulfur compounds to prevent corrosion of equipment containing brass fittings and copper tubing. However this test method is not applicable to liquefied petroleum gases containing corrosion inhibitors or any other agents which diminish the corrosivity of the sample to the copper strip. Methanol There is a possibility that a small amount of methanol may be present in LP-Gas. If methanol is present, ASTM D2713. "Standard Test Method for Dryness of Propane-Valve Freeze Method" is not applicable for determining the dryness of propane type products. Residual LP-gas as produced is normally free of residual matter, which includes those heavier hydrocarbons boiling above 100 OF, including any solid foreign materials. If residuals are present as shown by ASTM D-2158, "Standard Test Method for Residues in LP-Gas", and are in excess of the amount allowed by these specifications,such material may cause improper operation of regulators, vaporizers, or combustion apparatus. (1) NFPA 58 "Storage and Handling Liquefied Petroleum Gases''-National Park, Quincy, MA 02269 (2) Code of Federal Regulations, CFR 49:173.315@)(1)

Fire Protection Association, Battery-March

Other Trace Constituents Trace constituents other than those mentioned above can also be present in LP-gas as a natural occurrence or from processing. These may include olefins, mercury, and arsenic. Users of LP-gas with processes that can be harmed by these constituents are advised to take appropriate precautions to prevent damage to catalysts and/or process equipment from these trace materials.

...

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Certain refining processes can, during process upset or malfunction, result in contamination of LP-gas by fluoride compounds. Such contamination can be extremely destructive in the distribution and end user system. In addition, the combustion products of fluorides can cause physical damage to property and personal health. Similarly, fluorocarbons,such as certain refrigerants, can contaminate gas through dual use of storage or tankage facilities. Such contamination is rare but, if the possibility exists, users of LP-gas should take extreme precautions to insure the absence of fluorides.

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STD=GPA STD 2140-ENGL

1777 W 3824b77 O O L B C O O 0 7 T

(& Designation: D 1265 - 92

An Amencan National Standard

Standard Practice for Sampling Liquefied Petroleum (LP) Gases (Manual Method)‘ This standard is issued under the fixed designation D 1265; the number immediately following the designation indicates the year of onginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon (e) indicates an editorial change since the last revision or reapproval.

1. Scope

5. General Information

1.1 This practice covers the procedures for obtaining representative samples of liquefied petroleum gases such as propane, butane, or mixtures thereof, in containers other than those used in laboratory testing apparatus. These procedures are considered adequate for obtaining representative samples for all routine tests for LP gases required by Specification D 1835 except analysis by Test Method D 2 163. They are not intended for obtaining samples to be used for compositional analysis. A sample procedure that avoids changes in composition must be used for compositional analysis. NOTE l-Practice D3700 describes a recommended method for

5.1 Considerable effort is required to obtain a representative sample, especially if the material being sampled is a mixture of liquefied petroleum gases. The following factors must be considered: 5. I. 1 Obtain samples of the liquid phase only. 5 . I .2 When it is definitely known that the material being sampled is composed predominantly of only one liquefied petroleum gas, a liquid sample may be taken from any part of the vessel. 5.1.3 When the material being sampled has been agitated until uniformity is assured, a liquid sample may be taken from any part of the vessel. 5.1.4 Because of wide variation in the construction details of containers for liquefied petroleum gases, it is difficult to spec$ a uniform method for obtaining representative samples of heterogeneous mixtures. If it is not practicable to agitate a mixture for homogeneity, obtain liquid samples by a procedure which has been agreed upon by the contracting parties. 5.1.5 Directions for sampling cannot be made explicit enough to cover ail cases. They must be supplemented by judgment, skill, and sampling experience. Extreme care and good judgment are necessary to ensure samples which represent the general character and average condition of the material. Because of the hazards involved, liquefied petroleum gases should be sampled by, or under the supervision of, persons familiar with the necessary safety precautions.

obtaining a representative sample of a hydrocarbon fluid and the subsequent preparation of that sample for laboratory analysis.

1.2 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

2. Referenced Documents 2.1 ASTM Standards: D 1835 Specification for Liquefied Petroleum (LP) Gases’ D 2 163 Test Method for Analysis of Liquefied Petroleum (LP) Gases and Propene Concentrates by Gas Chromatography’ D 3700 Practice for Containing Hydrocarbon Fluid Samples Using a Floating Piston Cylinder3

NOTE2-Samples to be tested for presence of corrosive compounds or sulfur compounds should be taken in stainless steel containers equipped with stainless steel valves; otherwise, determinations of mercaptans and hydrogen sulfide, for example, can be misleading.

3. Summary of Practice

5.1.6 Hydrocarbon vapors vented during sampling must be controlled to assure compliance with applicable safety and environmental regulations. --````,,```,,,```,`,,,,,`,,````-`-`,,`,,`,`,,`---

3.1 A liquid sample is transferred from the source into a sample container by purging the container and filling it with liquid, then providing 20 % outage so that 80 % of the liquid volume remains.

6. Apparatus 6.1 Sample Container-Use metai sample containers of a type that ensures maximum safety and are resistant to corrosion by the product being sampled. A suitable material is stainless steel. The size of the container depends upon the amount of sample required for the laboratory tests to be made. The sample container should be fitted with an internal outage (ullage) tube to permit release of 20 95 of the container capacity. The end of the container fitted with the outage (ullage) tube shall be clearly marked. Typical sample containers are shown in Figs. 1 and 2. If the container is to be transported, it must often conform to specifications pubfished in Tariff No. 10, “I.C.C.Regulations for Transportation of Explosives and Other Dangerous Articles,” its supplements, or reissues.

4. Significance and Use 4.1 Samples of liquefied petroleum gases are examined by various test methods to determine physical and chemical charactenstics. The test results are often used for custody transfer and pricing determination. It is therefore essential that the samples be representative of the product to be tested. I This practice is under the joint jurisdiction of ASTM Committee D 2 on Petroleum and Petroleum Roducts and is the direct responsibility of Subcommittee DO2.H on Liquefied Petroleum Gas. Cumnt edition approved March 15, 1992. Published May 1992. Onginally published as D 1265 - 53 T.Last previous edition D 1265 - 87. 2 Annual Book of A S T M Standards, Vol 05.0I. 3 Annual Book of A S T M Siandards, Vols 05.02.



S T D - G P A S T D 2140-ENGL 1777

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OUTAGE (UIlAGE)TüBE

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INLET VALVEC

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FIG. 1 Typical Sample Container and Sampling Connections

OUTAGE

VALVE A

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VALVE D

FIG. 2

Typical Sample Container and Alternate Purging Connections



S T D = G P A STD 2 L V O - E N G L 1997 m 3 8 2 4 b 7 9 OULA502 942 m D1265 D. Close outlet valve D and release the remainder of the sample in the liquid phase by opening vent valve B. Repeat the purging operation at least three times.

6.2 Sample TransJer Line made of stainless steel tubing or other flexible metal hose, impervious to the product being sampled, is required. The most satisfactory line is one equipped with two valves on the sample-container end, Fig. 1, a control valve, A, and a vent valve, B.

9. Transfer of Sample 9.1 Position the sample container securely in an upright position with outlet valve D at the top (Fig. 1) and both valves C and D closed. 9.1.1 Close vent valve B, open the control valve A, open inlet valve C, and fill container with the sample. Close inlet valve C and the valve at the product source. Open vent valve B. After the pressure is fully reduced, disconnect sample container from the transfer line. Discard the sample if a leak develops or if either valve is opened during subsequent handling of the sample container before performing the outage (ullage) operations outlined in section 10.

PROCEDURE

7. Purging Sample Transfer Line 7.1 Connect the ends of the transfer line securely to the product source and to the inlet valve C of the container. Close the control valve A, vent valve B, and inlet valve C, Fig. 1. Open the valve at the product source and purge the transfer line by opening the control valve A and the vent valve B.

8. Purging the Sample Container 8.1 If the history of the sample container contents is not known or if traces of the previous product could affect the analysis to be camed out, or both, use the following purge procedure: 8.1.1 Connect valve D of the sample container to the sample transfer line with the container in an upright position and valve C at the top (Fig. 2). 8.1.2 Close valves B, C, and D. Open valve A and then valves C and D. Fill sample container until liquid issues from valve C. Close valves C and D, then valve A on the sampling line. 8.1.3 Loosen the connection joining the sample container to the sample line and turn container through 180" such that valve D is at the top. Open valves C and D and drain out liquid. 8.1.4 Return the sample container to position valve C at the top. Tighten connection to sample transfer line and repeat the purging operation at least three times. 8.2 If the history of the sample container contents is known, use the following purge procedure: 8.2.1 With the container in an upright position, Fig. 1, and its outlet valve D at the top, close vent valve B and inlet valve C and open control valve A. Open inlet valve C and partly fill the container with sample by slowly opening the outlet valve D. Close the control valve A and allow part of the sample to escape in the vapor phase through outlet valve

10. Sample Outage (Ullage) 10.1 Immediately after obtaining the sample, place the container in an upright positioin with the outage (ullage) tube at the top. 10.1.1 Open outlet valve D slightly. Allow excess liquid to escape and close the valve at the first sign of vapor. If no liquid escapes, discard the sample and refill the container. 11 Checking for Leaks

1 1.1 After eliminating the excess liquid so that only 80 % of the sample remains, immerse in a water bath and check for leaks. If a leak is detected at any time during the sampling operation, discard the sample. Repair or replace the leaky container before obtaining another sample. 12. Care of Samples

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12.1 Place samples in a cool location as soon as possible. Keep them there until all tests have been completed. Discard any samples in containers which develop leaks. Protect the valves on the sample container, either by packing the container in a crate in an approved manner or by using a protective cap, so that accidental unseating of the valve or tampering with it is avoided. 13 Keywords 13.1 liquified petroleum gases; LPG; sampling

The American Society for Testing and Materials takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this standard. Users of this standard are expressly advised that determination of the valid@ of any such patent rights, and the risk of infringement of such rights, are entirely their own responsibil@. This standard is subject to revision ai any time by the responsible technical committee and must be reviewed every five years and if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards and should be addressed to ASTM Headquarters. Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may attend. If you feel that your comments bave not received a fair hearing you should make your views known to the ASTM Committee on Standards. 1916 Race Sî., Philadelphia, PA 19103.



S T D - G P A S T D 2340-ENGL

3997 W 3824b77 0038503 889 W

Designation: D 1267 - 95

An American N a t i l Standard

Standard Test Method for

Gage Vapor Pressure of Liquefied Petroleum (LP) Gases (LP-Gas Method)' This standard is issued under the fixed designation D 1267; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon ( e ) indicates an editorial change since the last revision or reapproval.

1. Scope

1.1 This test method covers the determination of the gage vapor pressures of liquefied petroleum gas products at temperatures of 37.8"C (100°F) up to and including a test temperature of 70'C (1 58°F). 1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific hazard statements, see Note 2 and Annex A2. 1.3 The values stated in acceptable metric units are to be regarded as the standard. The values in parentheses are for information only. 2, Referenced Documents 2.1 ASTM Standards: D323 Test Method for Vapor Pressure of Petroleum Products (Reid Method)* D i265 Practice for Sampling Liquefied Petroleum (LP) Gases (Manual Method)2 E i Specification for ASTM Thermometers3 2.2 Institute of Petroleum Standard: IP 181 Sampling Petroleum Gases4

3. Terminology 3.1 Definition: 3.1. I vapor pressure-the pressure exerted by the vapor of a liquid when in equilibrium with the liquid. 3.2 Description of Term Specific to This Standard: 3.2.1 liquejied petroleum gases-narrow boiling range hydrocarbon mixtures consisting chiefly of propane or propylene, or both, (Warning-see Note i ) butanes and butylenes, or both, in which the content of hydrocarbon compounds of higher boiling point than 0°C (32°F) is less than 5 % by liquid volume, and whose gage vapor pressure at 37.8"C (100°F) is not greater than approximately 1550 kPa (225 psi). NOTE 1 : Warning-Extremely

4. Summary of 'Test Method 4.1 The test apparatus, consisting of two interconnected chambers and equipped with a suitable pressure gage, is purged with a portion of the sample which is then discarded. The apparatus is then filled completely with the portion of the sample to be tested. Thirty-three and one-third to forty volume percent of the sample content of the apparatus is immediately withdrawn to provide adequate free space for product expansion. The apparatus is then immersed in a water bath maintained at the standard test temperature of 37.8'C (100°F) or, optionally, at some higher test temperature up to and including a test temperature of 70°C (158°F). 4.2 The observed gage pressure at equilibrium, after correcting for gage error and correcting to a standard barometric pressure, is reported as the LPG Vapor Pressure at the selected test temperature.

5. Significance and Use 5.1 Information on the vapor pressures of liquefied petroleum gas products under temperature conditions from 37.8 to 70°C (1O0 to 158°F) is pertinent to selection of properly designed storage vessels, shipping containers, and customer utilization equipment to ensure safe handling of these products. 5.2 Determination of the vapor pressure of liquefied petroleum gas is important for safety reasons to ensure that the maximum operating design pressures of storage, handling, and fuel systems will not be exceeded under normal operating temperature conditions. 5.3 For liquefied petroleum gases, vapor pressure is an indirect measure of the most extreme low temperature conditions under which initial vaporization can be expected to occur. It can be considered a semi-quantitative measure of the amount of the most volatile material present in the product. 6. Apparatus 6.1 Vapor Pressure Apparatus, constructed as illustrated in Fig. A1.1, and the various items of auxiliary equipment, are completely described in Annex A 1. 6.2 The air chamber of Test Method D 323, may be interchangeable with the upper chamber of this method. Similarly, the liquid chamber (two-opening type) of Test Method D 323 is interchangeable with the Bt 20 % lower chamber Annex A1.1.4 of this method. Because of this interchangeability, the apparatus assembly of Test Method D 323 must pass, as a safety precaution, the hydrostatic test specified in A1.1.6 before using same in testing liquefied petroleum gas.

flammable. Harmful when inhaled.

This test method is under the jurisdiction of ASTM Committee D-2 on Petroleum Products and Lubricants and is the direct responsibility of Subcommittee W2.H on Liquefied Petroleum Gas. Current edition approved April 15, 1995. Published June 1995. Originally published as D 1267 - 53 T. Last previous edition D 1267 - 89. 2 Annual Book of ASTM Standards, Vol 05.01. 3 Annual Book ofASTM Standards, Vol 14.03. Available from Applied Science Publishers. Ripple Rd., Barking. Eswx, England --````,,```,,,```,`,,,,,`,,````-`-`,,`,,`,`,,`---


5 Licensee=UK LOCATION/5940240005 Not for Resale, 08/21/2007 09:17:10 MDT

7. Sampling and Sample Handling 7.1 Samples shall be obtained and stored in accordance with Practice D 1265, or IP 18 1, Sampling Petroleum Gases, unless the test samples can be taken directly from the source of the material to be tested. 7.2 Any method of coupling the vapor pressure apparatus to the sample source can be employed. Tubing, 6 to 7 mm (*/4 in.) in diameter, of minimum length, of suitable-working pressure, and made of material corrosion-resistant to the products being sampled, is satisfactory for this purpose. A flexible tubing connection of a satisfactory type greatly facilitates the purging and sampling operations. The tubing should be a conducting material or constructed with a built-in ground connection to minimize the effect of static electricity.

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9.3.2 When using the 20 9% lower chamber (Appendix A I. i .4), close the straight-through valve and again open the inlet to permit expulsion of the lower chamber contents. As soon as no more liquid escapes from the lower chamber, close the inlet valve and immediately open the straightthrough valve. 9.3.3 The upper chamber, prior to this operation, is liquid full at some temperature that is normally below the environmental temperature. Since any warming of the apparatus would cause expansion of the liquid content of the upper chamber, leading to possible rupture of the chamber, it is necessary that the procedural steps of providing free space in the apparatus be completed promptly. 9.4 Vapor Pressure Determination: 9.4.1 Invert the apparatus and shake it vigorously. Return the apparatus to its normal upright position and immerse it in the constant-temperature water bath maintained at the test temperature (4.1). The apparatus including the bleeder valve coupling, but not the pressure gage, must be immersed. Throughout the determination, the temperature of the water bath shall be checked periodically by means of the bath thermometer. 9.4.1.1 At test temperatures of 50°C (122°F) or below, maintain the bath at +O.l"C (0.2"F).At test temperatures above 50°C (122"F), up to and including 70°C (158'F), maintain the bath at t0.3"C (0.5"F). 9.4.1.2 Observe the apparatus assembly throughout the test period to ensure freedom from leaks. Discontinue the test and discard the results at any time a leak is detected. 9.4.2 After 5 min have elapsed, withdraw the apparatus from the water bath, invert it, shake it vigorously, and then return it to the bath. Perform the shaking operation quickly to avoid excessive cooling of the apparatus and its contents. Thereafter, at intervals of not less than 2 min, withdraw the apparatus from the bath, invert, shake it vigorously, and then return it to the bath. Prior to each removal of the apparatus from the water bath, tap the gage lightly and observe the pressure reading. These operations will normally require 20 to 30 min to ensure equilibrium. After this time, if consecutive observed gage readings are constant, record the pressure reading as the Uncorrected LP-Gas Vapor Pressure of the sample at the test temperature. 9.4.3 Without removing the pressure gage from the apparatus or the apparatus from the bath, attach a test gage, previously calibrated against a dead-weight tester, to the bleeder valve outlet and open the bleeder valve. At the end of 5 min compare the readings of the two gages. Record any correction thus determined as gage correction.

8. Preparation of Apparatus 8.1 If the apparatus has been used for testing products other than the type of product to be tested, disassemble, clean thoroughly, and purge the parts in a stream of dry air. 8.2 Assemble the apparatus with the inlet valve of the lower chamber open, the straight-through valve between the two chambers open, the bleeder valve closed, and with the proper range pressure gage attached.

9. Procedure 9.1 Safe means for the disposal of vapors and liquids during this operation and in the subsequent sampling operation must be provided. 9.2 Purging-With the assembled apparatus in an upright position, connect the inlet valve of the lower chamber to the sample source with the sampling connection (7.2). Open the sample source valve to the apparatus. Cautiously open the bleeder valve on the upper chamber, permitting the air or vapors, or both, in the apparatus to escape until the apparatus is full of liquid. Close the lower chamber inlet valve and open the bleeder valve to its wide.open position. Allow the contained liquid to evaporate until the apparatus is covered with white frost (may require more than one chilling), then invert the assembly, and expel any residual material through the bleeder valve. Allow the residual vapors to escape until the pressure in the apparatus is essentially atmospheric, then close the bleeder valve. 9.3 Sampling-Return the apparatus, now containing only vapors, to its normal upright position and open the inlet valve. As soon as the apparatus attains essentially the same pressure as the pressure of the sample source, momentarily open the bleeder valve. If liquid does not promptly emerge, repeat the purging step (9.2). If liquid appears immediately, close the bleeder and inlet valves in that order (Note 2). Close the valve on the sample source, and disconnect the sampling line. Immediately close the straight-through valve between the two chambers and open the inlet valve, with the apparatus in an upright position. Close the inlet valve as soon as no more liquid escapes, and immediately open the straight-through valve (Note i). NOTE 2-Transfer of the sample is facilitated by chilling the appa-

10. Calculation i O. i Correct the Uncorrected LP-Gas Vapor Pressure for gage errors. 10.2 Convert the corrected vapor pressure = (test gage reading) (gage correction) as calculated in 9.4.3 to a standard barometric pressure of 760 mm (29.92 in.) Hg by means of the following equation: 10.2.i LP-gas vapor pressure = corrected vapor pressure, kPa - (760 - P i )0.1333 (1) = corrected vapor pressure, psi - (760 - P i )0.0193 (2) where:

+

ratus with a portion of the material under test.

9.3.1 When using the 33% 9% lower chamber (Aí.l.3) proceed to 9.4. Copyright Gas Processors Association Provided by IHS under license with GPA No reproduction or networking permitted without license from IHS

6


S T D - G P A S T D 2L40-ENGL 1777

m

382qb79 0018505 b5L

m

D 1267 PI = observed barometric pressure, mm Hg. 10.2.2 LP-gas vapor pressure

-

= corrected vapor pressure, kPa - (29.92 P2) 3.3864 = corrected vapor pressure, psi - (29.92 - P2)0.49 12

(3) (4)

where:

P2 = observed barometric pressure, in. Hg. 10.2.3 Conversion Factors: 1 kPa = 7.50064 mmHg = 0.295301 in. Hg 1 psi = 5 1.7 15 1 mmHg = 2.03603 in. Hg

(5) (6) (7)

11. Report 11.1 Report the LP-Gas vapor pressure test results in terms of kilopascals to the nearest 5 kPa or pounds per square inch, gage, to the half unit, and the test temperature.

12. Precision and Bias 12.1 The following shall be used as a basis for judging the acceptability of results (95 % probability). 12.1.1 Repeutabiliry-The difference between two test results, obtained by the same operator with the same apparatus

under constant operating conditions on identical test materials would in the normal and correct operation of the test method, exceed the following value only in one case in twenty: 12 kPa ( 1.8 psi) 12.1.2 Reproducibility-The difference between two single and independent results obtained by different operators working in different laboratories on identical test material would in the long run, in the normal and correct operation of the test method, exceed the following value only in one case in twenty: 19 kPa (2.8 psi) 12.2 Bias-The procedure in Test Method D 1267 for measuring vapor pressure has no bias because the value of vapor pressure is defined only in terms of this test method.

13. Keywords 13.1 natural gas liquids; liquified petroleum gases; vapor pressure

ANNEXES (Mandatory Information)

Al. 1 Vapor Pressure Apparatus, consisting of two chambers, designated as the upper and lower chambers, shall conform to the following requirements. To maintain the correct volume ratio between the upper and lower chambers, the units shall not be interchanged without recalibrating to ascertain that the volume ratio is within satisfactory limits. A 1.1.1 Upper Chamber-This chamber, as shown in Fig. Al.1 (c), shall be a cylindrical vessel 51 f 3 mm (2 k in.) in diameter and 254 f 3 mm ( I O t l/8 in.) in length, inside dimensions, with the inner surfaces of the ends slightly sloped to provide complete drainage from either end when held in a vertical position. On one end of the chamber, a suitable bleeder-valve coupling (Fig. Al.l (e)) shall be provided to receive the bleeder-valve assembly and the pressure gage. In the other end of the chamber an opening approximately 13 mm ( V 2 in.) in diameter shall be provided for coupling with the lower chamber. Care shall be taken that the connections to the end openings do not prevent the chamber from draining completely. A 1.1.2 Bleeder- Valve Assembly-The bleeder-valve for purging the apparatus (Fig. Al.l) (d)) shall be a normal 6 mm (V4 in.) valve fitted into the side of the bleeder-valve coupling (Fig. A I . 1 (e)). The lower end shall be threaded to fit into the end fitting of the upper chamber, and the upper end shall be threaded to receive the gage coupling (Fig. AI. 1 (h)). A 1.1.3 Lower Chamber, 33V3 % (Fig. A l . 1 (b))-This chamber shall be a cylindrical vessel of such a volume that the ratio of the volume of the upper chamber to the volume of the lower chamber is between the limits of 1.97 to 2.03 (Note A 1.2).

A I . 1.4 Lower Chamber, 20 % (Fig. A l . I (b))-This chamber shall be a cylindrical vessel of such a volume that the ratio of the volume of the upper chamber to the volume of the lower chamber is between the limits of 3.95 to 4.05 (Note A 1.2) (Note A 1.3). In one end of the lower chamber, an opening approximately 19 mm (3/4 in.) in diameter shall be provided to receive a suitable straight-through valve (Fig. Al.l (g)) having a minimum internal channel of 13 mm (Y2 in.) in diameter. The other end of the chamber shall be equipped with a nominal 6 mm ( Y 4 in.) inlet valve. NOTEAl. 1-In determining the volumetric capacities of the chambers, the volume of the lower chamber is considered as that which is below the "straight-through" valve closure. The volume above the "straight-through" valve closure, including the portion of the coupling attached to the upper chamber, is considered as a part of the upper chamber volume. The volume ratios of the chambers are determined in accordance with the procedure outlined in the Appendix of Test Method D 323. NOTEAl .3-The apparatus requirements for this method, excluding the bleeder-valve assembly, are identical with those of Test Method D 323 with the exception of the 33V3 % lower chamber. Although the test procedural details are different, the air and liquid chambers of Test Methcd D 323 may be used in the present method provided they are of sufficient strength to withstand the higher test pressures (A I 1.6). I

A1.1.5 Method of Coupling Upper und Lower Chambers-Any method of coupling the chambers can be employed provided the volumetric requirements are met and that the assembly is free from leaks under the conditions of the test. A 1.1.6 Hydrostatic Test-The assembled chambers shall be certified by the manufacturer to withstand approximately 6920 kPa (loo0 psi) gage hydrostatic pressure without permanent deformation.



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Al. APPARATUS FOR VAPOR PRESSURE OF LIQUEFIED PETROLEUM (LP) GASES

D1267

' 1G ,

( S T R A I G H T - THROUGH VALVE)

PLINGI

VALVE

COUPLIPJG 1

l

L F( I N L E T

VALVE)

--````,,```,,,```,`,,,,,`,,````-`-`,,`,,`,`,,`---

FIG. A l . l

Typical LPG Vapor Pressure Apparatus

A I . 1.7 Checking for Freedom from Leaks-Before placing new apparatus in service, and as often as necessary thereafter, the assembled vapor pressure apparatus shall be checked for freedom from leaks by filling it with air, natural gas, nitrogen, or other similar gases, to 3460 kPa (500 psi) gage pressure, and then completely immersing it in a water bath. Only apparatus that will stand this test without leaking shaii be used. A 1.2 Pressure Gage-The pressure gage, shown in Fig. A l . l (a), shall be a Bourdon-type spring gage of test gage quality 114 to 140 mm (4% to 5% in.) in diameter provided with a nominal 6 mm (V4 in.) male thread connection with a passageway not less than 5 mm (Y16 in.) in diameter from the Bourdon tube to the atmosphere. The range and graduations of the pressure gage used shall be governed by the vapor pressure of the sample being tested, as follows: Gage to Be Used

LP-Gas Vapor Pressure, kPa (psi) gage at test temperature 655 (95) and under 620 (90) to 1750 (250) 1660 (240) to 3460 (5001

Scale Range, kPa (psi) O to 700 (100) O to 1750 (250) O to 3500 (500)

considered inaccurate. A 1.3 Vapor Pressure Bath-The vapor pressure bath (water) shall be of such dimensions that the vapor pressure apparatus may be immersed so as to completely cover the bleeder valve when the assembly is in an upright position. Means for maintaining the bath at the test temperature (2. I ) within the range as follows: ( I ) Test temperature 50°C (122°F) and below, +O.l"C (0.2"F); (2) Test temperature above 50°C (122'F), +0.3"C (0.5"F). In order to check the bath temperatures, the appropriate bath thermometer shall be immersed to the test temperature mark on the thermometer scale throughout the vapor pressure determination. A 1.4 Thermometers-Only thermometers conforming to specificationsin Specification E 1 or IP Standard Thennometer Specificationsshall be used. The range shall be governed by the test temperature of the test being used as follows: Test Temperature ThermomThermometer Range 'C "C eter No. 35 to 40 18C 34 to 42 50 to 80 65C 50 to 80

Numbered Intermediate Intervals, Graduations, kPa (psi) kPa (psi) 70 (IO)

"F

172 (25)

7 (I)

344 (50)

35 (5)

95

Only accurate gages shall be continued in use. When the gage correction exceeds 2 96 of the scale range, the gage shall be


"F

to 105 18F 94 to 108 125 to 175 65F 122 to 176 A 1.4.1 At other test temperatures a total immersion thermometer shall be used having a range that brackets the test temperature and a maximum scale error of O. 1°C (0.2"F). A 1.5 Dead- Weight Tester-A dead-weight tester of satisfactory range shall be provided as a means for checking the accuracy of vapor pressure gages.

3.4 (0.5)


~

~~

~

STDmGPA S T D 21LiO-ENGL 1777 m 382Lib77 0038507 LI2LI m

D 1267 A2. PRECAUTIONARY STATEMENT A2.1.5 Avoid buildur, of vapors and eliminate all sources

A2.1 ProDane/Butane. or Mixture of Both .

A2.1.1 A2.1.2 A2.1.3 A2.1.4

I

Vapors can cause flash fires. Keep away from heat, sparks, and open flame. Keep container closed. Use with adequate ventilation.

of ignition, especially nonexplosion-proof electrical apparatus and heaters. A2.1.6 Avoid prolonged breathing of vapor or spray mist. A2.1.7 Avoid prolonged or repeated skin contact.

The American Society for Testing and Materials takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights. and the risk of infringement of such rights. are entirely their own responsibility.

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This standard is subject to revision at any time by the responsible fechnical committee and must be reviewed every five years and if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards and should be addressed to ASTM Headquarters. Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should make your views known to the ASTM Committee on Standards, 1916 Race St., Philadelphia, PA 19103.



4m


An American National Standard


Density or Relative Density of Light Hydrocarbons by Pressure Thermohydrometer' This standard is issued under the fixed designation D 1657; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A supemript epsilon (e) indicates an editorial change since the last revision or reapproval.

reference temperatures in general use are 15'C and 60'F for both tl and t2, but other temperatures may be employed for t,.

1. Scope 1.1 This test method covers the determination of the relative density or density of light hydrocarbons including liquefied petroleum gases (LPG). 1.2 The prescribed apparatus should not be used for materials having vapor pressures higher than 1.4 MPa (1 4 bar) at the test temperature. (The SI unit of pressure is the pascal: 1 Pa = 1 N/m2; lo5 Pa = 1 bar = 1.01972 k&cm2.)

4. Summary of Test Method 4.1 The apparatus is purged with a portion of the sample before filling with the portion to be used for testing. The pressure cylinder is filled to a level at which the enclosed hydrometer floats freely. The hydrometer reading and the temperature of the sample are noted.

NOTE1-Attention is drawn to the hazards encountered when working with liquefied petroleum gas or light hydrocarbons. The requirements of any national, local, or domestic safety code should always be strictly observed.

5. Significance and Use 5.1 The density or relative density of light hydrocarbons and liquefied petroleum gases is determined to satis@ transportation, storage, and regulatory requirements. Although this determination does not describe any particular performancecharacteristic, density or relative density can be used to indicate approximate component concentrations in liquefied petroleum mixtures.

1.3 The values in SI units are to be regarded as the standard. The values in parentheses are for information only. 1.4 This standard may involve hazardous materiais, operations, and equipment. This standard does not purport to address all of the safety problems associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. --````,,```,,,```,`,,,,,`,,````-`-`,,`,,`,`,,`---

6. Apparatus4 6.1 Thermohydrometers, made of glass, graduated in density with a range from 500 to 650 ks/m3, or in relative density with a wide range from 0.500 to 0.650, and conforming to the dimensions given in Table 1. 6.2 Hydrometer Cylinder, constructed of giass or transparent plastic; for example, poly(methy1 methacrylate) or equivalent material, conforming to the design and dimensions given in Fig. 1. The ends shall be tightly sealed with neoprene gaskets and metal end plates as shown in Fig. 1. 6.2.1 Caution-A protective shield shall be placed around the plastic or glass cylinder. Replace any cylinders that show signs of fogging, crazing, cracking, or etching. NOTE3-Certain compounds attack plastics and cloud the inner

2. Referenced Documents

2.1 ASTM Standards: D 1250 Guide for Petroleum Measurement Tables (ASTM 1250/API 2540/IP 200)2 E 100 Specification for ASTM Hydrometers3 3. Terminology 3.1 Dejnitions: 3.1.1 density-the mass of the liquid per unit volume at a temperature t. 3.1.2 relative density (this term now replaces the former term "specific gravity")-the ratio of the mass of a given volume of the liquid at a temperature t , to the mass of an equal volume of pure water at a temperature t2.

surface of the cylinder, making it difficult or impossible to read the hydrometer. Tests showed no attack by ethane, ethylene, propane, propylene, butane, isobutane, normal butylenes, isobutylene, pentane, and isopentane, and no attack is expected from butadiene and acetaldehyde. Users are cautioned, however, to clean the cylinder thoroughly after each determination. Ketones and alcohols should not be used for cleaning as they attack and weaken plastics while aromatics also tend to attack the surface of plastics and should similarly not be used.

NOTE2-When reporting the density, the units of mass and volume used, together with the temperature, should be explicitly stated, for example, kg/m3 at fC. The standard reference temperatures are 15°C and 60°F. When reporting the relative density, the temperatures t , and t2 should be explicitly stated; for example, relative density 60/60'F. The standard

6.2.2 The liquid inlet valve and the liquid outlet valve shall be tightly connected to a base plate that shall be bored to give both valves a common inlet to the cylinder. The

* This test method is under the jurisdiction of ASTM Committee D-2 on Petroleum products and Lubricants and is the direct responsibility of Subcommittee W 2 . 0 2 . K on Density. Current edition approved March 31, 1989. Published May 1989. Onginally published as D 1657 - 39 T. Last previous edition D 1657 - 83 (1988)''. Annual Book of ASTM Siandnrds, Vol. 05.01. Annual Book of ASTM Standards, Vol 14.03.

4Apparatus suitable for this test may be obtained from: EG&G Chandler Engineering, 7707 E. 38th St., Tulsa, OK 74145; Peter Peterson Scientific Glassblowing, Inc., 473 Elmira Rd., Guelph, Ontario NIK 1C2; and Refinery Supply Co., Inc., 6901 E. 12th St., Tulsa, OK 741 12.



TABLE 1 Thermohydrometer For Petroleum Products and Other Liquids of Similar Surface Tensions i33 dvnes/cm or less) Thermometer Scale in Body ASTM Hydrometer No.

Nominal Relative Density Range

1O1H-62

0.500 to 0.650

Hydrometer Total length, mm Body diameter, mm Stem diameter min, mm Working pressure min, psi

354 to 366 19 to 22 10.5 200 Hydrometer Scale

Standard temperature, O F Subdivisions Intermediate lines at Main (numbered) lines at Scale error at any point not to exceed Length of nominal scale, rnm

60/60 0.001 0.005 0.01o 0.001 125 to 145

Thermometer Scale

30 to 90 total 1 5 10 0.5

Range, O F Immersion Subdivisions, O F Intermediate lines at, O F Main (numbered)lines at, OF Scale error at any point not to exceed, OF Scale length, mm

50 to 70 LIOUID INLET

Thermohydrometer (Pressure) ASTM Hydrometer No.

Density Range, kglm3

310H

500-650

I

VALVE \I

I

:EDLE

'LET

Hydrometer

387 16 to 22 10.5 1400 Hvdrometer Scale

Standard temperature, O C Subdivisions, kg/m3 Intermediate lines at, kg/m3 Main (numbered)lines at, kg/m3 Scale error at any point not to exceed, kglm3 Length of nominal scale, mm

15

302-1

\.

__.-I

FIG. 1 Pressure Thermohydrometer Cylinder

1

5 10 1 125 to 145

vapor vent valve shall be similarly connected to the top plate, which shall be bored to provide a vapor outlet from the pressure cylinder. All valves shall be 6.3 mm ( V 4 in.) or equivalent needle valves. 6.2.3 The cylinder shall not be operated at a gage pressure greater than 1.4 MPa (14 bar). 6.3 Water Bath, fitted with a thermostat or other means of maintaining the bath at a constant temperature of 15 k 0.2"C (60 k OSOF), and of such dimensions that the cylinder can be completely immersed. 7. Reference Liquids 7.1 The following reference liquids are required for standardization of the hydrometer: 7.1.1 Propane, pure grade, having a nominal density of


/

507.6 kg/m3 at 15'C or a relative density 60/60"F of 0.50699. 7.1.2 n-Butane, pure grade, having a nominal density of 584.1 kg/m3 at 15°C or a relative density 60/60"F of 0.5840.

8. Sampling 8.1 The procedure for sampling for calibration of the apparatus and for subsequent testing is described as follows: 8.1.1 Connect the source of supply of the liquid to be tested to the inlet valve by suitable fittings so that a representative sample can be introduced into the cylinder. Ascertain that these connections are free of leaks. Open the outlet valve and purge the sampling connections by opening the inlet valve slightly, permitting the product to flow through the outlet valve at the bottom of the cylinder. 8.1.2 When the connections have been purged, close the outlet and vent valves and open the inlet valve, permitting the liquid to enter the cylinder until it is full. If necessary, the vent valve can be opened slightly to permit complete filling of the cylinder and then closed. At no time shall the pressure


--````,,```,,,```,`,,,,,`,,````-`-`,,`,,`,`,,`---

Nominal length, mm Body diameter, mm Nominal stem diameter, mm Working pressure, kPa

382Lib77 UOL85LU T L 7 U

S T D - G P A STD 2L40-ENGL 2 7 7 7

dm

D 1657

in the cylinder be allowed to rise above a gage pressure of 1.4 MPa. 8.1.3 When the cylinder has been filled, close the inlet valve and open the outlet valve, permitting the contents of the cylinder to be withdrawn completely and the pressure inside the cylinder to be reduced to that of the atmosphere. 8.1.4 Close the outlet valve and open the inlet valve, filling the cylinder to a level at which the enclosed thermohydrometer floats freely. If it is necessary to accomplish this filling by venting vapor through the vent valve, repeat the purging to cool the cylinder sufficiently to permit its being filled without the necessity of venting. 8.1.5 With all valves closed, examine the apparatus for leaks. If leaks are detected, discard the sample, reduce the pressure to atmospheric and repair the leaks. Repeat the sampling procedure.

the liquid level will improve the visibility of the surface. Estimate the hydrometer reading to the nearest one-fifth scale division. 9.8 Repeat with a second sample. Average the two results, if these differ by less than 0.0005, deduct the average from the relative density or density of the reference liquid to obtain the correction to be applied. 9.8.1 If the two results differ by more than 0.0005, repeat the determinations. 9.8.2 After each determination, empty the cylinder and vent to reduce the pressure to atmospheric. 10. Procedure

10.1 Purge and empty the apparatus and draw a sample of the product to be tested as in Section 8. 10.2 Disconnect the cylinder and place it in the water bath maintained at approximately 15°C or 60'F until the temperature of the contents has reached 15 +I 0.2"C or 60 f 0.5"F as indicated by the thermometer. In order to accelerate thermal adjustment, occasionally remove the apparatus from the water bath, gently invert and tilt, and replace in the water bath. Exercise care during this operation to prevent damage to the enclosed thermohydrometer. 10.3 When the product in the cylinder has reached a constant temperature of 15 f 0.2"C or 60 f 0.5"F, remove the apparatus from the water bath and while the thermohydrometer is floating freely, observe and record the thermohydrometer reading as quickly as possible. Read and record the temperature to the nearest 0.2"C or 0.5"F. Immediately after each determination, empty the liquid from the cylinder and vent to reduce the pressure to atmospheric. Highly volatile liquids and liquefied petroleum gases must not be left in the apparatus since at high ambient temperatures; they might generate sufficient pressure to burst the cylinder. 10.3.1 If so used, the cylinder must be vented and the test discarded if the pressure in the cylinder rises above a gage pressure of 1.4 MPa (14 bar).

9. Calibration of Apparatus

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9.1 Carefully clean and dry the thermohydrometer and the inside wall of the pressure cylinder. 9.2 Insert the thermohydrometer in the pressure cylinder. Connect the source of supply of the reference liquid to the inlet valve and ascertain that the connections are free of leaks. Open the outlet valve and purge the connections by opening the inlet valve slightly. 9.3 When the connections have been purged, close the outlet and vent valves and open the inlet valve, permitting the liquid to enter the cylinder until it is full. If necessary, the vent valve can be opened slightly to permit complete filling, after which it should be closed. The pressure of the cylinder must never rise above a gage pressure of 1.4 MPa (14 bar). 9.4 When the cylinder has been filled, close the inlet valve and open the outlet valve, permitting the liquid to be withdrawn completely and the pressure inside the cylinder to be reduced to atmosphere. 9.5 Close the outlet valve and open the inlet valve, filling the cylinder to a level where the enclosed thermohydrometer floats freely. If the vapor pressure is too high to permit adequate filling, the cylinder must be cooled. This is accomplished by repeating the purging operation. When the cylinder is filled to the normal operating level, close the inlet valve and examine the apparatus for leaks. If any are detected, withdraw the liquid, reduce the pressure to atmospheric and repair the leaks. Repeat the purging and filling operations. 9.6 Disconnect the cylinder from the source of supply of liquid and place it in the water bath maintained at 15 f 0.2'C or 60 2 0.5"F until thermal equilibrium has been obtained. To accelerate thermal adjustment, occasionally remove the cylinder from the water bath, tilt to a horizontal position, rock gently a few times to ensure mixing, and replace in the water bath. Exercise care to prevent damage to the thermohydrometer. 9.7 Remove the cylinder from the water bath, stand it on a firm level surface, and while the hydrometer is floating freely, take the hydrometer reading promptly in the following manner: Observe a point slightly below the plane of the liquid surface and then raise the line of vision until this surface, seen as an ellipse, becomes a straight line. The point where this line cuts the hydrometer scale is the reading of the instrument. A white card held behind the cylinder just below

NOTE&For measurements in the field, this method may be used at ambient temperatures, with the realization that the accuracy is decreased. 11. Report 1 1.1 Correct the observed thermohydrometer reading and report the corrected reading to the nearest unit of density or the nearest 0.001 relative density. 11.2 The result must be reported in accordance with the Petroleum Measurement Tables (Section 2), using Table 53B for correction of density to 15'C or Table 23B for correction of relative density to 6O/6O0F.

12. Precision and Bias 12.1 The precision of procedure in this test method has not been determined but is under consideration. 12.2 The bias of the procedure in this test method has not been determined.



The American Society lor Testing and Materials takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risk of infringement of such rights, are entireiy their own responsibility. This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards and should be addressed to ASTM Headquarters. Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should make your views known to the ASTM Committee on Standards, 1916 Race St., Philadelphia, PA 19703.

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13



[&


An American Naaonal Standard

Standard Test Method for Volatility of Liquefied Petroleum (LP) Gases’ This standard is issued under the fixed designation D 1837; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript epsiion (0indicates an editorial change since the last revision or reapproval.

1. Scope 1.1 This test method is a measure of the relative purity of the various types of liquefied petroleum (LP) gases and helps to ensure suitable volatility performance. The test results, when properly related to vapor pressure and density of the product, can be used to indicate the presence of butane and heavier components in propane type LP-gas, and pentane and heavier components in propane-butane and butane type fuels. The presence of hydrocarbon compounds less volatile than those of which the LP-gas is primarily composed is indicated by an increase in the 95 % evaporated temperature. 1.2 Chromatographic analysis should be used when the concentration and type of higher boiling compounds must be identified. 1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

TABLE 1 Weatherinn Tube Graduation Tolerances scale limit of Range, mL

0.0 to 0.1 0.1 to 0.3

0.3to 0.5 0.5to 1.0 1 .O to 3.0 3.0to 5.0 5.0to 25.0 25.0to 100.0

0.05 0.05 0.05 0.1 0.1 0.5 1 .o

0.02 0.03 0.05 0.05

1 .o

0.1 0.2 0.5 1.o

5. Apparatus 5.1 Weathering Tube-A centrifuge tube, cone-shaped, conforming to the dimensions given in Fig. 1 and made of thoroughly annealed heat-resistant glass.4 The shape of the lower tip of the tube is especially important. The taper shail be uniform and the bottom shall be rounded as shown in Fig. 1. The tubes shall comply in wall thickness to ASTM centrifuge tube requirements (Note 1). The graduation tolerances are given in Table 1.

2.1 ASTM Standards: D96 Test Methods for Water and Sediment in Crude Oil by Centrifuge Method (Field Procedure)2 D 1796 Test Method for Water and Sediment in Fuel Oils by the Centrifuge Method (Laboratory Procedure)2 E 1 Specification for ASTM Thermometers3

NOTE1-Requirements for centrifuge tubes appear in Test Methods D 96 and D 1796.

3. Summary of Test Method 3.1 The product is refrigerated by means of a cooling coil, and 100 mL of the liquid is collected in a weathering tube. The liquid is allowed to weather under specified conditions ’ has evaporated. and the temperature is observed when 95 % Correction for variation of barometric pressure is made.

5.2 Tube Support-Means shail be provided for s u p porting the weathering tube by its neck in a vertical position. 5.3 Water Bath (for use in tests on butane and propanebutane mixture types of liquefied petroleum gas only). A shallow container filed with clean water having a maintained temperature ranging from 15 to 2 1°C (60 to 70’F) and a depth of 38 mm (1Y2 in.). 5.4 Thermometer-ASTM Armored Weathering Test Thermometer having a range from -50 to 5°C (-58 to 41°F) and conforming to the requirements for Thermometer 99C-92 (99F-86) as prescribed in Specification E 1. 5.5 Sampling Precooling Equipment: 5.5.1 Cooling Vessel-Any suitable wide-mouthed metai container or Dewar flask at least 64 mm (2V2 in.) in inside

4. Signüícance and Use 4.1 Volatility, expressed in terms of the 95 % evaporated i temperature of the product, is a measure of the amount of least volatile fuel components present in the product. Cou1 This test method is under the jurisdiction of ASTM Committee D-2 on Petroleum Products and Lubricants and is the direct responsibility of Subcommittee DO2.H on Liquified Petroleum Gas. Current edition approved July 15, 1994. Published September 1994. Originally pübhhed as D 1837 - 61 T.Last PXV~OUS edition D 1837 - 92. 2 Annual Book of ASTM Standards, Vol 05.01. 3 Annual Book of ASTM Standarh, Vol 14.03.

--````,,```,,,```,`,,,,,`,,````-`-`,,`,,`,`,,`---

EITOT.mL

pled with a vapor pressure limit, it serves to ensure essentially singlecomponent products in the cases of commercial propane and commercial butane fuel types. When volatility is coupled with a vapor pressure limit which has been related to gravity, as in the case of the commercial PB-mixture type of fuels, the combination serves to assure essentially two component mixtures for such fuels. When coupled with a proper vapor pressure limit, this measurement serves to assure that specialduty propane products will be composed chiefly of propane and propylene and that propane will be the major constituent.



Division. rnL

Borosilicate @ass has been found satisfactory for this purpose.


~

~

S T D - G P A S T D 2190-ENGL 1997 m 3 8 2 9 b ï î 0018513 7 2 8 [$)9

DI837

TOLEWCE 3 m m (118 in.)

above. Connect the downstream end of the coil to a 3.2 mm (I/s in.) needle valve having an outlet connection not more than 76 mm (3 in.) long (see Fig. 2). 5.5.3 Precoolant-This can be the liquefied petroleum gas from the same container from which a sample is to be taken. Other refrigerants having a boiling point lower than the initial boiling point of the sample can be used. Use a nonflammable precoolant if required.

6. Procedure 6.1 Obtaining a Test Sample-Fiil the cooling vessel with the precoolant so as to cover the cooling coil. Attach the inlet of the cooling coil to the source from which the sample is to be taken with a short line connection of 6.4 mm ( Y 4 in.) pipe (or larger), having a sampling valve large enough to prevent vaporization of the material due to the drop in pressure across the valve seat. Purge the sampling line and cooling coil by opening both the sampling valve and the 3.2 mm (118 in.) needle valve on the downstream end of the cooling coil. Fiü the weathering tube with the sample flowing through the cooling coil. Empty this first sample, add one or two grains of charcoal, and then refill the weathering tube to the 100-mL mark with fresh liquid sample passing through the cooling coil. Carefully inseri the precooled armored thermometer as low as possible into the centrifuge tube (Note 2). Center the armored thermometer in the tube by means of a slotted cork. NOTE2-Do not remove the armor from the thennometer during the test. Place the bottom of the armor as low in the centrifuge tube as it will go, pipet in 5 mL of water, and observe the water level in the tube. 3.2 rnrn (118 in.) NEEDLE VALW

SAMPLE VALVE

6 m (20 R.) OF 4.8 mm (3i16 in.) O.D. 4 SOFT COPPER TUBING

-It

METAL OR GLASS COOLING VESSEL

6.4m m (114in.)

MIN.INSIDE DIAMETER

NOTE-FOT graduation tderances see TaMe 1.

FIG. 1 Weatheringlube

diameter by 292 mm (1 1 i/z in.) deep. 5.5.2 Cooling Coil-Approximately 6 m (20 fi) of 4.8-mm (%-in.) outside diameter soft copper tubing, wound around a hollow mandrel at least 54 mm (2% in.) in outside diameter, with adjacent turns touching. Run the lower end of the tube up through the center of the mandrel before winding so that the finished coil will fit snugly inside the cooling vessel. When assembled, the top of the coil must be at least 25 mm ( i in.) below the top of the cooling vessel and the open ends of the coil must not be more than a few inches --````,,```,,,```,`,,,,,`,,````-`-`,,`,,`,`,,`---


i--1 64 rnm (2 l i 2 in.)

NOTE-The

coils in the drawing are extended for danty.

FIG. 2


Preceding Equipment

S T D - G P A STD 2 1 4 0 - E N G L 1997

3824679 0018519 bbll

D1837 Take the 5 I residue readings at this same level with the armored thermometer in the same position.

6.2 Weathering Butane and Propane-Butane Mixture Types of Liquefed Petroleum Gas Products-When the temperature of the sample is below -12'C (10"F), allow it to weather in the atmosphere until the temperature has reached -12°C (10°F). At this point, place the weathering tube, with the armored thermometer still in place, in the water bath in a vertical position, submerging it to the IVz-mL mark, and allow the contents to weather. 6.3 Weathering Propane Type of Liquefied Petroleum Gas Products-Allow the sample to weather in the atmosphere, taking care to disturb the frost on the tube as little as possible. An acetone or alcohol swab can be used to remove frost sufficient to permit reading of the temperature. 6.4 Reading of Temperature-When the liquid level in the weathering tube, with the armored thermometer still in place, corresponds with the level previously determined when the 5 mL of water was put in the weathering tube (see Note 2), read and record the temperature of the sample in accordance with 6.2 and 6.3. 6.5 Temperature Correction-Following the final temperature reading (6.4), remove the armored thermometer from the weathering tube and place it in a bath of finely crushed ice up to the immersion point. Observe the reading of the thermometer when a constant reading is obtained. If the thermometer reading is less than 0°C (32"F),add the fraction of a degree it is low to the final test reading. If the thermometer reading is more than 0" (32"F), subtract the fraction of a degree that it is high from the final test reading. Discard any thermometer that varies more than 0.5"C (1'F) in either direction from 0°C (32°F). NOTE3-A high reading of the thermometer when it is placed in ice usually indicates that there is a break in the mercury-thallium thread. This can be corrected by warming the thermometer gently in a warm water bath to drive the break upward into the expansion chamber at the top of the thermometer. While the mercury-thallium is continuous in the upper chamber, tap the bottom of the thermometer on a hard, but cushioned surface, to join the liquid into a continuous thread. A low reading in ice usually indicates that some of the liquid has remained in the expansion chamber. To correct this, allow the thermometer to warm so the liquid enters the chamber and tap as previously instructed.

( 5 5% residue) for the thermometer error (6.5).

7.2 Correct the observed temperature for the thermometer error from the observed atmospheric pressure in kPa (millimetres of mercury) to a base barometric pressure of 101.33 kPa (760 mm). 7.3 In the weathering test for propane, add 0.3"C ( 0 3 ° F ) to the corrected temperature for each 1.3 kPa (10 mm Hg) that the test is conducted below 101.33 kPa (760 mm) pressure, or subtract 0.3'C ( 0 3 ° F ) from the observed temperature for each 1.3 kPa (10 mm Hg) that the test is conducted above 101.33 kPa (760 mm). 7.4 In the weathering test for butane and propane-butane mixtures, add 0.4"C (0.7"F)to the corrected temperature for each 1.3 kPa (10 mm Hg) that the test is conducted below 101.33 kPa (760 mm) pressure, or subtract 0.4"C (0.7"F) from the observed temperature for each 1.3 kPa (10 mm Hg) that the test is conducted above 101.33 kPa (760 mm). 8. Precision and Bias 8.1 The following criteria should be used for judging the acceptability of results (95 % confidence): 8.1.1 Repeatability-The difference between two test results obtained by the same operator with the same apparatus under constant operating conditions on identical test materials would in the normal and correct operation of the test method, exceed the following value only in one case in twenty: S6'C ( 1 .VF)

8.1.2 Reproducibility-The difference between two single and independent results obtained by different operators working in different laboratories on identical test material would in the long run, in the normal and correct operation of the test method, exceed the following value only in one case in twenty: 95°C (1.7'F) for butane and propane-butane mixtures and 1.28"C (2.3"F) for propane. 8.2 Bias-The procedure in this test method for measuring volatility of LP-gases has no bias because the volatility is defined only in terms of this test method.

9. Keywords 9.1 butane; liquefied petroleum (LP) gases; propane; LPG; volatility

7. Interpretation of Results 7.1 Correct the thermometer at the 95 9% boiling point

The American Society for Testing and Materials takes no p i t i o n respecting the validity of any palen?rights asserted in connection with any item mentioned in this standard. Users of this standard are expressly edvised that determination of the validity of any such petent rights, and the risk of infringement of such rights, are entirely their own responsibility. This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and il not revised. either reepproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards and should be addressed to ASTM Headquaaers. Your comments will receive careful consideration at a meeting Ot the responsible technical committee, which you may attend. If you feel that your comments have no? received a fair hearing you should make your views known to the ASTM Committee on Standards, 7916 Race St., Philadelphia, PA 19103.

--````,,```,,,```,`,,,,,`,,````-`-`,,`,,`,`,,`---



4Tb




Copper Strip Corrosion by Liquefied Petroleum (LP) Gases' This standard is issued under the fixed designation D 1838; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon (0 indicates an editorial change since the last revision or reapproval.

1. Scope 1.1 This test method detects the presence of components in liquefied petroleum gases which may be corrosive to copper. NOTE 1-For an equivalent copper strip test applicable to less volatile petroleum products, see Test Method D 130.

1.2 The values stated in acceptable metric units are to be regarded as the standard. The values in parentheses are for information only. 1.3 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific hazard statements, see 6.1, 8.3. I , and Annex A l .

6.4 mm (V4-in.) pipe. The whole assembly shall be capable of withstanding a hydrostatic test pressure of 6895 kPa (loo0 psig). No leak shall be discernible when tested at 3450 kPa (500 psig) with gas. 5.2 Water Bath, capable of being maintained at 37.8 k 0.5'C (100 k 1°F).Incorporate suitable supports to hold the test cylinder in an upright position. Make the bath deep enough so that the entire cylinder and valves will be covered during the test. 5.3 Thermometer-An ASTM Density Thermometer having a range from -20 to 105°C(-5 to +215"F), graduated in 0.2"C (0.5"F) subdivisions, and conforming to the requirements for Thermometer 12C ( 12F), as prescribed in Specification E 1. 5.4 Strip Polishing Vise, to hold the copper strip firmly

--````,,```,,,```,`,,,,,`,,````-`-`,,`,,`,`,,`---

2. Referenced Documents 2.1 ASTM Standards: D 130 Test Method for Detection of Copper Corrosion from Petroleum Products by the Copper Strip Tarnish Test2 E 1 Specification for ASTM Thermometers3

Needle Valve A

3. Summary of Test Method 3.2 m m I.D.

3.1 A polished copper strip is immersed in approximately 100 mL of the sample and exposed at a temperature of 37.8"C (100°F) for 1 h in a cylinder of suitable working pressure. At the end of this period, the copper strip is removed and rated as one of the four classifications of the ASTM Copper Corrosion Standards.

Neoprene O-Ring Outage Tube

Mote rial:

4. Significance and Use 4.1 Copper corrosion limits provide assurance that dificulties will not be experienced in deterioration of the copper and copper-alloy fittings and connections that are commonly used in many types of utilization, storage, and transportation equipment.

1 5 2 . 4 mm (6 i n . )

1

I

76.2 mm

( 3 in.)

6.4 m m Min. (114 in.)

5. Apparatus 5.1 Corrosion Test Cylinder, constructed of stainless steel with an O-ring removable top closure according to the dimensions given in Fig. 1. Provide a flexible aluminum connecting hose with swivel connections with adapter to a

/ 6.4 mm (1/4in.)

n

Needle Valve B

Metric Equivalents

mm

in.

mm

'/a

3.2

3

76

'14

6.4 6

152

in.

' This test

method is under the jurisdiction of ASTM Commitîee D-2 on Petroleum Products and Lubricants and is the direct responsibility of Subcommittee W2.H on Liquefied Petroleum Gas. Current edition approved Aug. 15, 1991. Published October 1991. Originally published as D 1838 - 61 T.Last previous edition D 1838 - 89. *Annual Book ofASTM Siandards, Vol 05.01. Annual Book ofASTM Siandards, Vol 14.03.

38.1

1 '/z

FIG. 1 Copper Sûip Corrosion Test Cylinder



without marring the edges. For convenient vises see Test Method D 130.

6. Materials 6.1 Wash Solvenf-Use acetone or knock test grade 2.2.4 trimethylpentane. NOTE2: Warning-Extremely flammable. See Annex A 1. 6.2 Copper Strip, 12.5 mm ( V 2 in.) wide, 1.5 to 3.0 mm ('116 to '/E in.) thick, cut 75 mm (3 in.) long from smoothsurfaced, hard-temper, cold-finished copper of 99.9+ percent purity; electrical bus bar stock is generally suitable. Drill a 3.2 mm (I/8 in.) hole approximately 3.2 mm ('/8 in.) from one end in the center of the strip. The strips can be used repeatedly but should be discarded if the surfaces become deformed. 6.3 Polishing Materials-Silicon carbide grit paper of various degrees of fineness including 65-pm (24O-fit) paper or cloth; also a supply of 105ym (150-mesh) silicon carbide grain and pharmaceutical grade absorbent cotton (cotton wool). 6.4 Copper Corrosion Standard Plaques are a~ailable.~ Their care and inspection for stability are described in detail in Test Method D 130.

7. Preparation of Strips

--````,,```,,,```,`,,,,,`,,````-`-`,,`,,`,`,,`---

7.1 SurJice Preparation-Remove all surface blemishes from all six sides of the strip with silicon carbide grit paper of such degrees of fineness as are needed to accomplish the desired results efficiently. Finish with 65-pm (240-grit) silicon carbide paper or cloth, removing all marks that were made by other grades of paper used previously. Immerse the strip in wash solvent from which it can be withdrawn immediately for final polishing or in which it can be stored for future use. 7.1.1 As a practical manual polishing procedure, place a sheet of the paper on a flat surface, moisten it with wash solvent and rub the strip against the paper with a rotary motion, protecting the strip from contact with the fingers with an ashless filter paper. Alternatively, the strip can be prepared by use of motor-driven machines using appropriate grades of dry paper on cloth. 1.2 Final Polishing-Remove a strip from the wash solvent. Holding it in the fingers protected with ashless filter paper, polish first the ends and then the sides with the 105-pm (1 50-mesh) silicon carbide grains picked up from a clean @ass plate with a pad of absorbent cotton moistened with a drop of wash solvent. Wipe vigorously with fresh pads of absorbent cotton and subsequently handle only with stainless steel forceps; do not touch with the fingers. Clamp in a vise and polish the main surfaces with silicon carbide grains on absorbent cotton. Rub in the direction of the long axis of the strip, carrying the stroke beyond the end of the strip before reversing the direction. Clean all metal dust from the strip by rubbing vigorously with clean pads of absorbent cotton until a fresh pad remains unsoiled. When the strip is clean immediately attach to the dip tube and immerse it in the prepared test bomb.

7.2.1 It is important to polish the whole surface of the strip uniformly to obtain a uniformly stained strip. If the edges show wear (surface elliptical) they will likely show more corrosion than the center. The use of a vise will facilitate uniform polishing.

8. Procedure 8.1 With valve B (Fig. i), open, place approximately 1 mL of distilled water into a clean test cylinder and swirl to moisten the walls; allow the remainder to drain from the cylinder, insert the freshly polished copper strip suspended from the hook on the dip tube making sure that the bottom of the strip is at least 6.4 mm (1/4 in.) from the bottom of the cylinder when assembled. After assembly of the apparatus, close both valve A (Fig. i), on closure assembly with outage tube, and valve B. 8.2 Holding the test cylinder upright so as not to wet the copper strip with water, attach the sample source to the test cylinder valve A (Fig. 1) by means of a short length of flexible aluminum tubing that has been purged with the sample. Admit some sample to the cylinder by opening the valve at the sample source and then valve A. 8.3 Close valve A without disconnecting the test cylinder from the sample source. Invert the test cylinder and open valve B to purge the air from the test cylinder. Return the test cylinder to the upright position and drain any residual liquid through the open valve B. Close valve B with the test cylinder now in its upright position, open valve A and fill the test cylinder with the sample. When the test cylinder is full, close valve A, the valve at the sample source, and disconnect the aluminum tubing. 8.3.1 Warning-Safe means for the disposal of vapors and liquids during this and subsequent procedures must be provided. 8.4 As soon as the aluminum tubing is disconnected, and with the cylinder in its upright position, open valve A slightly so that all liquid above the end of the outage tube will be removed from the test cylinder. When vapor first emerges from valve A, close valve A. 8.5 Immediately after filling, immerse the test cylinder in the water bath maintained at 37.8 f 0.5'C (100 f 1'F). Ailow the cylinder to remain in the bath for 1 h f 5 min. 8.6 At the end of the test period remove the cylinder from the bath and, holding the cylinder in a vertical position, open the bottom valve to a suitable disposal unit (8.3.1) until all of the liquid and most of the vapor is discharged. 8.7 When only a slight pressure remains in the cylinder, disassemble immediately and compare at once the copper strip that has been exposed to the liquefied petroleum gases with the ASTM Copper Strip Corrosion Standards. 8.8 If the copper strip shows any appreciable discoloration, the interior of the cylinder should be polished with steel wool and washed with wash solvent soon after use so as to be clean for another test. 9. Interpretation of Results 9.1 Handling only with stainless steel forceps, compare the exposed strip with the ASTM Copper Strip Corrosion Standards. Hold both the test strip and the standard in such a manner that light reflected from them at an angle of approximately 45" will be observed. In handling the test strip

The ASTM Copper Strip Corrosion Standards approved by Committee D-2 are available from ASTM Headquarters. Request Adjunct No. 12-401300-00.



3777 W 382qb77 0038537 373

during the inspection and comparison, the danger of marking or staining can be avoided if it is inserted in a flat test tube which is then stoppered with absorbent cotton.

10. Report 10.1 Report the results in accordance with one of the classifications listed in Table I . State the duration of the test and the test temperature. 10.2 The added distilled water frequently causes isolated brown spots on the copper strip. The presence of these spots should be disregarded or the test should be repeated. 11. Precision and Bias 1 1.1 In the case of ordinal classification data, no generally accepted method for determining precision or bias is currently available.

12. Keywords 12.1 corrosivity; liquefied petroleum gases

TABLE 1 ASTM Copper Strip Classifications ___

Classification

Designation

Description"

Freshly polished strip

...

B

1

Slight tarnish

Light orange, almost the same as a freshly polished strip Dark orange

2

Moderate tarnish

Claret red Lavender Multicoiored with lavender Mue and/or silver overlaid on claret red Silvery Brassy or gdd

3

Dark tarnish

Magenta overcast on brassy strip MultiMored with red and green showing (peacock), but no gray

4

Conosion

Transparent black, dark gray o< brown with peacock green barely showing Graohite or lusterless biack Glossy or jet black

A The ASTM Copper Corrosion Standard is made up to strips characteristic of these descriptions. 8 The freshly polished strip is included in a series only as an indication of the appearance of a properly polished strip before a test run; it is not possible to duplicate this appearance after a test even with a completely nonmosive sample.

ANNEX (Mandatory Information) Al. PRECAUTIONARY STATEMENT Al.1 2.2.4 Trimethyìpentane

Keep away from heat, sparks, and open flame. Keep container closed. Use with adequate ventilation.

Avoid build-up of vapors and eliminate all sources of ignition, especially non-explosion proof electrical apparatus and heaters. Avoid prolonged breathing of vapor or spray mist. Avoid prolonged or repeated skin contact.

The American Society for Testing and Materials takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risk of infringement of such rights, are entirely their own responsibility. This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and if not revised. either reapproved or withdrawn. Your commnts are invited either for revision of this standard or for additional standards and should be addressed to ASTM Headquarters. Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should make your views known to lhe ASTM Committee on Standards, 1916 Race St., Philadelphia, PA 19103.



--````,,```,,,```,`,,,,,`,,````-`-`,,`,,`,`,,`---

STD*GPA STD 2340-ENGL

4cRi

Designation: D 2158

- 92

An Americen National Standard

@ Designation: 317195 Standard Test Method for

Residues in Liquefied Petroleum (LP) Gases' This standard is issued under the fixed designation D 2158; the number immediately following the designation indicates the year of onginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon (e) indicates an editorial change since the last revision or reapproval.


2.1 ASTM Standards: D 96 Test Methods for Water and Sediment in Crude Oil by Centrifuge Method (Field Procedure)2 D 1796 Test Method for Water and Sediment in Fuel Oils by the Centrifuge Method (Laboratory Procedure)2 D 1835 Specification for Liquefied Petroleum (LP) Gases2 E 1 Specification for ASTM Thermometers3 2.2 Other Documents: GPA Publication 2 1404 IP Appendix AS

3. Terminology 3.1 Descriptions of Terms Specific to This Standard: 3.1.1 residue-the volume, measured to the nearest 0.05 mL, of the residual material boiling above 38°C resulting from the evaporation of 100 mL of sample under the specified conditions of this test method. 3.1.2 R Number -the residue multiplied by 200.

3.1.3 oil stain observation-the volume of solvent-residue mixture required to yield an oil ring that persists for 2 min under specified conditions on a prescribed filter paper. 3.1.4 O Number -10 divided by the oil stain observation. 4. Summary of Test Method 4.1 A 100-mL sample of liquefied petroleum gas is weathered in a 100-mL centrifuge tube. The volume of residue remaining at 38°C is measured and recorded as is also the appearance of a fdter paper to which the residue has been added in measured increments.

5. Significance and Use 5.1 Control over the residue content (required by Specification D 1835) is of considerable importance in end-use applications. In liquid feed systems residues may lead to troublesome deposits and, in vapor offtake systems, residues that are carried over can foul regulating equipment. Those that remain will accumulate, can be corrosive, and will contaminate following product. Water, particularly if alkaline, can cause failure of regulating equipment and corrosion of metals. 6. Apparatus

6.1 Centrifuge Tube, 100-mL graduated, conforming to dimensions given in Fig, 1. The first 0.5 mL shall be graduated in 0.05-mL increments. The shape of the lower tip of the tube is especially important. The taper shall be uniform and the bottom shail be rounded as shown in Fig. 1. Tubes shall be made of thoroughly annealed heat-resistant glass. Volumetric graduation tolerances, based on air-free water at 2VC, are given in Table 1. Detailed requirements for centrifuge tubes appear in Test Methods D 9 6 and D 1796. 6.2 Cooling Coil, a minimum length of 6 m of 5 to 7-mm outside diameter copper tubing wound to a diameter of 63.5 TABLE i . Centrifuge Tube Graduation Tolerances Range. mL

This test method is under the jurisdiction of ASTM Committee D-2 on Petroleum Products and Lubricants and is the direct responsibility of Subcommittee W2.H on Liquid Petroleum Gas. Current edition approved Apr. 15, 1992. Published June 1992. Originally published as D 2 i 58 - 63 T. Last previous edition D 2 I58 - 89. 2 Annual Book ofASTM Standards, Vol 05.01. 3 Annual Book of ASTM Standards, Vol 14.03. Available from Gas Processors Assn., 6526 E. 60th St., Tulsa, OK 74145. Available from Institute of Petroleum, 61 Cavendish St., London. 'VIL4 P 4 R 1

0.0to

0.1

0.1 to 0.3 0.3to 0.5 0.5 to 1.0 1.0 to 3.0 3.0to 5.0 5.0 to 25.0 25.0 to 100.0



scale,

Limit of

Division. mL

Error,

0.05 0.05 0.05 0.1 0.1 0.5 1.o

0.02

1.o

mL

0.03 0.05 0.05 0.1 0.2 0.5 1.o

--````,,```,,,```,`,,,,,`,,````-`-`,,`,,`,`,,`---

1. Scope 1.1 This test method covers the determination of the extraneous materials weathering above 38°C that are present in liquefied petroleum gases. 1.2 Liquefied petroleum gases that contain alcohols to enhance their anti-icing behaviour can give erroneous results by this test method. 1.3 The result can be expressed in terms of measured volumes or indices derived from these volumes. In either case, the test method provides an indication of the quantity and nature of materials in the product that are substantially less volatile than the liquefied petroleum gas hydrocarbons. 1.4 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific precautionary statements, see 6.9.

Copper Wire 3mm NEEDLE VALVE

d 17 z 1 mmiO

SAMPLE VALVE

6mm

6m OF 5mm O.D. SOFT COPPER TUBING

METALOR GLASS COOCINGMSSEL

+ 36.W-37 75 mm O 0

I /

7

-

10 mL

--````,,```,,,```,`,,,,,`,,````-`-`,,`,,`,`,,`---

I

02-90 mm NOTE-CO¡IS

in the drawing are extended for clarity.

FIG. 2

Precooling Equipment

*

~ino oi inside bottom

FIG. 1

7. Reagents and Materials 7.1 Sofvent-Oil-free, reagent-grade pentane or cyclopentane.

INSIDE TAPER SHAPE Cone-Shaped Centrifuge Tube, 203 mm

NOTE2-Although pentane is the preferred solvent for use in this test method, cyclopentane can be substituted for pentane whenever the ambient temperature or altitude is too high to enable the convenient handling of pentane.

t 1.5 mm outside diameter, and assembled in a suitable cooling bath. (See Fig. 2.) 6.3 Syringe, 1-mL (ordinary medical syringe), graduated in 0.1 mL and equipped with a needle 200 f 5 mm long. Alternatively, a O. 1-mL pipet may be used. 6.4 Thermometers, conforming to Specification E 1 or IP Appendix A. Low Range-Minus 38'C to +50"C High Range-Minus 20°C to +SUC

8. Preparation of Apparatus 8.1 Wash all glassware that is to be used in the test in the selected solvent. Add 10 mL of a new sample of solvent to the centrifuge tube. Mark the center of the filter paper. Fill the syringe or pipet with a portion of the solvent drawn from the centrifuge tube and direct 0.1 mL of the solvent to the mark on the paper. Allow the solvent to evaporate and note the persistence of an oil ring. Attempt to cover a circle of about 30 to 35 mm in diameter on the filter paper with each addition. If no oil ring appears after 1.5 mL of solvent has been added, the solvent and glassware are satisfactory. The appearance of an oil ring indicates either improperly cleaned glassware or contaminated solvent.

1P IC/ASTM 5C ASTM 57C

NOTEI-When

a thermometer or a water bath, or both, are not available, for example, a field test, a satisfactory alternative for screening is to warm the tip of the centrifuge tube with the hand.

6.5 Filter Paper, medium-grade, rapid, white, 125-mm diameter. 6.6 Solvent Wash Bottle. 6.7 Water Bath, controlled at 38 t 2°C.


*

6.8 Copper Wire, 1.6 0.1-mm diameter, 300 10-mm long. 6.9 Clamp, suitable for holding the centrifuge tube during weathering.


temperature is above 5°C. If it is necessary to determine the oil ring at temperatures below 5"C,allow 10 min for oil ring persistence.

8.2 The presence of an oil ring should be observed by holding the dry filter paper between the eye and a bright incandescent light or strong daylight. 8.3 The solvent is added in 0.1-mL increments to confine the solvent ring to a circle of about 30 to 35 mm in diameter. The filter paper should be held level during the solvent addition. One method is to place it on the 250-mL beaker.

NOTE3-As an acceptable alternative to the procedure given in 9.2 for use in those cases where a product specification limit has been established, continued incremental additions of the solvent-residue mixture that is equivalent to the limiting specification can be made to the filter paper and, if no persistent oil ring appears, the result of the test shall be reported as passing.

9. Procedure 9.1 Residue-Attach the cooling coil to the sample source, cool the coil to below the boiling point of the sample, and flush the coil and sampling line. 9.1.1 Rinse the centrifuge tube with the material to be sampled and then fill it to the 100-mL mark with a representative sample. 9.1.2 Immediately insert the copper wire through a clean, slotted cork or a clean, loose-fitting plug of cotton or cleansing tissue in the mouth of the centrifuge tube. The wire helps to prevent superheating and resulting bumping (erratic or excessive boiling), and the cork (or plug) will keep out air or moisture while the sample is weathering. If more than 10 mL of the sample is lost because of bumping, obtain a new sample. 9.1.3 Allow the sample to weather, using artificial heating, if the ambient temperature or type of sample requires it. If, when weathering has ceased and the tube has reached ambient temperature, a residue remains, place the tip of the tube in a water bath at 38°C for 5 min. 9.1.4 Record the volume of any remaining residue to the nearest 0.05 mL, and the presence of extraneous matter, if observed. 9.2 Oil Stain Observation-Add sufficient solvent to the centrifuge tube containing the residue described in 9.1.4 to restore the volume to 10 mL. Add the solvent from the wash bottle and carefully wash down the sides of the tube. Stir well with the syringe needle or pipet so that any residue at the bottom of the tube is dissolved uniformly in the solvent. 9.2.1 Mark the center of a clean white filter paper. Fill the syringe or pipet and direct 1.5 mL of the solvent-residue mixture at a rate such that the wetted circle is maintained at about 30 to 35 mm in diameter. 9.2.2 If no oil ring persists after a 2-min waiting period when holding the dry filter paper between the eye and a bright incandescent light or strong daylight, discontinue the test. 9.2.3 If a ring is discernible, determine the volume of the solvent-residue mixture at which the oil ring first persists for 2 min on a new filter paper by adding the solvent-residue mixture in O. 1-mL increments. 9.2.4 Record the volume in mL of the solvent-residue mixture required to yield a persistent oil ring as the oil stain observation. 9.3 Storage of oil-free solvent in a polyethylene wash bottle for several days contaminates the solvent. Any solvent transferred to the wash bottle for purposes of running the test should either be used in testing during the same day or discarded. 9.4 It has been noted that at low ambient temperatures (below about 5°C) materials in the gasoline boiling range will leave an oil ring that persists after 2 min. Oil ring determinations should be made in a protected area where the

10. Calculation 10.1 R Number-Multiply the volume of residue obtained in 9.1.4 by 200. 10.2 O Number-Divide 10 by the oil stain observation obtained in 9.2.4. If the oil stain observation exceeds 1.5 mL, the result is recorded as zero. 11. Expression of Results 1 1.1 Volumetric-The results shall be expressed as: 11.1.1 Residue on evaporation to the nearest 0.05 mL, and 1 1.1.2 Oil stain observation to the nearest O. 1 mL. 1 1.2 Normalized-The results shall be expressed as: 1 1.2.1 R Number to the nearest 10, and I 1.2.2 O Number to the nearest 1. 12. Precision and Bias

12.1 Precision is only expressed in terms of the normalized reporting units. 12.2 Repeatability-The difference (r) between successive test results obtained by the same operator with the same apparatus under constant operating conditions on identical test material would, in the long run, in the normal and correct operation of the test method, exceed the values below only in one case in twenty: O Number

r

o to 20 20to 40

4

o to ?O

5

6

40 to 100

8

20 to 40 40 to 60

10 20

r

--````,,```,,,```,`,,,,,`,,````-`-`,,`,,`,`,,`---

12.3 Reproducibilitjp-The difference (R) between two test results independently obtained by different operators operating in different laboratories on nominally identical test material would, in the long run, in the normal and correct operation of the test method, exceed the values below only in one case in twenty: R

R Number

R

6

o to 20

IO

20to 40

8

40 to 100

I?

20 to 40 40 to 60

20 30

O Number

o to

20

12.4 Bias-The procedure in this test method for measuring residues in LP-Gas has no bias because the residues are defined only in terms of this test method.

13. Keywords 13.1 liquified petroleum gases; LPG; residue


R Number


S T D - G P A S T D 2LYü-ENGL

1777

=

382Lib79 O O L 8 5 2 L 8T4

(tm

D2158

This standard is subject to revision at any time by the responsible technical cornminee and must be reviewed every five years and il not revised, either reapproved or withdrawn. Your comments are invited either lor revision of this standard or lor additional standards and should be addressed to ASTM Headquarters. Your comments will receive careful consideration at a meeting of the responsible technical cornminee, which you may attend. If you lee/ that your comments have not received a fair hearing you should make your views known to the ASTM Comminee on Standards, 1916 Race St., Philadelphia. PA 19703.



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The American Society tor Testing and Materials takes no position respecting the validity of any paient rights asserted in connection with any item mentioned in this standard Users 01 this standard are expressly advised that determination of the validity 01 any such patent rights, and the risk o1 mlringement o1 such rights. are entirely their own responsibility

4”



@ Designation: 264/79 (85) Standard Test Method for

Analysis of Liquefied Petroleum (LP) Gases and Propene Concentrates by Gas Chromatography’ This standard is issued under the fixed designation D 2163; the number immediately following the designation indicates the year of onginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon (z) indicates an editorial cl-ange since the last revision or reapprovai.

1. Scope

5. Significance and Use

1.1 This test method covers the determination of the composition of liquefied petroleum (LP) gases. It is applicable to analysis of propane, propene, and butane in all concentration ranges O. 1 % and above. 1.2 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 1.3 The values stated in SI units are to be regarded as standard.

5.1 The component distribution of liquefied petroleum gases and propene concentrates is often required as a specification analysis for end-use sale of this material. Its wide use as chemical feedstocks or as fuel, require precise compositional data to ensure uniform quality of the desired reaction products. 5.2 The component distribution data of liquefied petroleum gases and propene concentrates can be used to calculate physical properties such as relative density, vapor pressure, and motor octane (see Practice D 2598). Precision and accuracy of compositional data are extremely important when these data are used to calculate various properties of these petroleum products.

2. Referenced Documents 2.1 ASTM Standards: D 242 1 Practice for Interconversion of Analysis of C5 and Lighter Hydrocarbons to Gas-Volume, Liquid-Volume, or Weight Basis2 D 2598 Practice for Calculation of Certain Physical Properties of Liquified Petroleum (LP) Gases from Compositional Analysis3 D 3700 Practice for Containing Hydrocarbon Fluid Samples Using a Floating Piston Cylinder3

3. Terminology 3.1 Definition: 3.1.1 propene concentrate-concentrate than 50 % propene.

6. Gas Chromatograph System 6.1 Detector-The detector shall be a thermal conductivity type or its equivalent in sensitivity and stability. The system shall be capable of detecting 0.1 9% concentration of any component of interest. For calculation techniques utilizing a recorder, the signai for the concentration shall be at least 5 chart divisions above the noise level on a O to 100 scale chart. Noise level must be restricted to a maximum of 1 chart division. When electronic integration is employed the signal for 0.1 % concentration must be at least twice the noise level. 6.2 Recorder-A strip-Chari recorder and integrator with a full-scale range of 10 mV or less shall be required. A maximum full-scale balance time of 2 s and a minimum chart speed of */2 in. (12.7 mm)/min shall be required. 6.3 Arfenuator-A multistep attenuator for the detector output signal shall be necessary to maintain maximum peaks within the recorder chart range. The attenuator system must be accurate to 0.5 % in any position. 6.4 Sample Inlet System-Provision shall be made to introduce up to 0.50 mL of the sample. The sample volume must be repeatable such that successive runs agree within 1 mm or 1 9% (whichever is larger) on each component peak height. 6.5 Temperature Control-The analyzer columns shall be maintained at a temperature constant to 0.3”C during the course of the sample and corresponding reference standard runs.

containing more

4. Summary of Test Method 4.1 Components in a sample of LP gas are physically separated by gas chromatography and compared to corresponding components separated under identical operating conditions from a reference standard mixture of known composition or from use of pure hydrocarbons. The chromatogram of the sample is interpreted by comparing peak heights or areas with those obtained on the reference standard mixture of pure hydrocarbons. 1 This test method is under the jurisdiction of ASTM Committee D-2 on Petroleum Products and Lubricants and is the direct responsibility of Subcommittee W2.W.03 on C4 Test Methods Liquefied Petroleum Gas. Current edition approved Oct. 15, I99 l . Published December 1991. Originally published as D 2163 - 63. Last previous edition D 2163 - 87. 2 Annual Book of ASTM Standards, Vol 05.01. 3 Annual Book of ASTM Standards, Vol 05.02.

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24



= 382Lib77

S T D - G P A S T D ZL'iU-ENGL 1 7 7 7

0038523 b77

D2163 TABLE 1 Reference Standard Mixtures, Uquid Volume Percent * ~~

Component

Propane wdh No ünsaturates

Propane wdh Low

4

4

93

a7

Ethane Propane.

Butane

ProPane-

pro(iene

mopene

Butane Mixtures

with Low

WithHigh

ROaane

RoOane

2 45 6

0.2 4.8 94.9

30

0.1

...

4

3 57 35

1

1 3

1 3

,..

...

...

64 25 6

...

1

1

1

2

2

...

R O W

n-Butane Isobutane Butene isopentam A

propene

propane wdh High Propene

1

3

...

15

... ... ...

0.1 22.6 76.6

0.5

... 0.2

...

The compositii values recorded in this tabie are offered as a guide to laboCatories preparing their Own mixtures irm pure hydrocerbais or to commeráai suppkrs

of standards. In either case, an accurate composition oi the standards must be known to anaiyst.

7. Calibration Sîandard 7.1 Pure components or calibration standard mixtures4 may be used for calibration. If pure components are used, identical volumes of each component are injected into the chromatograph and relative area response factors are determined. These factors are valid for a given instrument and operating conditions and should be redetermined periodically. If pure components are used for calibration, the

\ FIG. 1 Illustration of AI6 Ratio

6.6 Carrier Gas-The instrument shall be equipped with suitable facilities to provide a flow of camer gas through the analyzer column at a flow rate that is constant to 1.0 5% throughout the analysis. 6.7 Columns-Any column may be used provided all component peaks for compounds present in concentration of more than 5 %I are resolved so that the ratio A/B shall not be less than 0.8, where: A = depth of the valley on either side of peak B, and B = height above the baseline of the smaller of any two adjacent peaks (see Fig. 1). For compounds present in concentrations of 5 %Y or less, the ratio of A / B shall not be less than 0.4. In case the smallcomponent peak is adjacent to a large one, it may be necessary to construct the baseline of the small peak tangent to the curve as shown in Fig. 2.

I

FIG. 2

calculation should be made in mole percent and converted to liquid volume percent mote i). Factors repeatable to within 1 % are required. The concentration of each component in the calibration standard mixtures shall be known to within 0.1 %. The concentration of the major component in the calibration standard mixture shall not differ from that of the like component in the sample to be analyzed by more than 10 % if the peak height method of calculation is used. On propene concentrates, the calibration standard mixtures shall not differ from that of like component in the sample to be analyzed by more than 5 %. Typical composition ranges of suitable calibration standard mixtures are given in Table 1. NOTEI-TH Method D 2421 may be used whenever a need exists for such translations.

8. Procedure 8.1 Apparatus Preparation-Mount the column suitable for the analysis desired (see Appendix Xi) in the chromatograph and adjust the conditions to optimum for the column selected (Table 2). Allow sufficient time for the instrument to reach equilibrium as indicated by a stable base line. 8.1.1 The test method allows the user a wide latitude in choice of instrumentation to make the analysis, and most commercial instrumentation easily meets the requirements defined in the test method. However, only by strict adherence to the calibration procedures outlined in the method can reproducibility between instruments expect to be achieved. 8.1.2 Proper maintenance of instrumentation is critical to continued satisfactory performance of this analysis. Clean sample containers, clean sample inlet systems and clean detectors are mandatory to achieve the precision and accuracy capabilities of this method. NOTE2: Warning-Samples and reference mixtures are extremely flammable. Keep away from heat, sparks,and flames. Use with adequate Suitable reference standard mixtures of pure hydrocarbonsarc available from the Phillips Petroleum Co., Special Products Div., Bartlaville, OK.

Illustration of A/B Ratio for Small-Component Peak

25

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TABLE 2

Column Diameter.

Column Length, m

Silicon 200/500 Benzyl cyanide-silver nitrate Hexamethylphosphoramide Dimethylsuifolane pius benzyl cyanide and silver nitrate Dimethylsuifolane Hexamethyl phosphoramide Di-n-butyl maleate Tricresyl phosphate plus silicone, 550 Methoxy ethoxy ethyl ether

Instrument Conditions

mm.OD

Substrate,

Mass, %

Temperature, OC

Flow Rate, mLlmin

Carrier G

60 to 70 45 to 55 60 to 70 60 to 70

helium helium helium helium

30 12

helium helium helium helium helium

-I

4 9 9

6.4 6.4 6.4

27

90

36 17

40 30

7

6.4

36

35

15 6 4 9 9

6.4 3.2 6.4 6.4 6.4

30

25 28 28

25

25

30 30

35 30

60 70 60

TABLE 3 Piecirion Data for LPG Containing Less Than 50 X Propene Concentration Range of C o m m n t s . mol %

O to 70 Above 70

Repeatability

Reproducibility

use repeatability curve in Fig. 3 0.2

use reproducibility curve in Fig. 3

ventilation. Cylinders must by supported at all times. Hydrocarbon vapors that may be vented must be controlled to assure compliance with applicable safety and environmental regulations. Vapor reduces oxygen available for breathing. Liquid causes cold bums.

often be attributed to improper sampling procedures. (See Test Method D 3700.) 8.3 Preparation ofthe Chromatogram-Obtain duplicate chromatograms of the sample. Adjust the attenuator at each peak for maximum peak height within the recorder chart range. Peak heights of like components shall agree within 1 mm or 1 % ! (whichever is larger). If a reference standard mixture is used for calibration, obtain duplicate chromatograms of the proper reference standard in a similar manner. Use the same sample size for all runs.

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8.2 Preparation and Introduction of Sample-Attach the cylinder containing the gas mixture to the sampling valve of the chromatograph so that a liquid phase sample is withdrawn. Adjust the flow rate from the sample cylinder so that complete vaporization of the liquid occurs at the cylinder valve. (An alternative technique is to trap a sample of only liquid phase in a short section of tubing, and then permit the entire sample to vaporize into an evacuated container). Adjust the ratio of the two volumes so that a gage pressure of 69 to 138 kPa (10 to 20 psi) is obtained in the final container. Then use this sample for the analysis. Fiush the sample loop for 1 to 2 min at a flow rate of 5 to 10 mL/min before introducing the sample into the &er gas stream. 8.2.1 On propene concentrates, the sample may be introduced as a liquid by means of a liquid sample valve or by vaporization of the liquid as above. On propene concentrates having a propene content of less than 80 %, only the alternative technique of trapping a sample of liquid and vaporizing the entire sample into an evacuated container shall be used. 8.2.2 Sampling at the sample source and at the chromatograph must always be done in a manner that ensures that a representative sample is being analyzed. Lack of precision and accuracy in using this method can most TABLE 4 COmpOUnd

Ethane

0.0 to 0.1 0.2

Propene Propane Butanes

70 to 77 93 to 95 5 to 7 22 to 29 0.0 to 0.1 0.5

NOTE 3-The use of planimeters or integrators is permissible provided their repeatability has been established and the resulting repeatability does not adversely afiìect the repeatability and reproducibility limits of the method given in Section 10.

Repeatability Reproducibility 0.02 0.05

0.04

0.38 0.34

1.5

0.33

1 .o

0.04

1

0.04 0.1 0.1

0.2

0.07

0.6 Butenes

9. Calculation 9.1 Peak Height Method-Measure the peak height of each component and adjust this value to the attenuation of the same component in the reference standard mixture. Calculate the percentage by mole or liquid volume of each component as follows: Concentration, liquid volume or moi percent = (PJP,)x S where: P, = peak height of component in the sample, Po = peak height of component in reference standard mixture, and S = percentage of mole or liquid volume of component in reference standard mixture. 9.2 Area Method-Measure the area of each component by multiplying the height of the peak by the width at half height. The width should be measured with the aid of a magnifying glass (Note 3). Adjust the area to the attenuation of the same component in the reference standard mixture.

Piecision Data for Propene Concentrates Concentration, moi %

1 % oí amount present

0.06 1.o

9.2.1 Calculate the percentage by mole or liquid volume of each component as follows:

1.o 1.7 0.08

Concentration, liquid volume or mol percent = (AJA,) x S

0.2

where: A, = area of component in sample, A, = area of component in reference standard mixture, and

0.3 0.5 0.2



382Lib99 0 0 1 8 5 2 5 L(L(T

1997

Precision, 95 Percent Confidence Limit

FIG. 3 Precision Curves

percentage by mole or liquid volume of component in reference standard mixture. 9.2.2 If pure components are used for calibration, calculate the composition as follows:

S

=

Concentration, mol percent

= AJAfl

where: A , = area of component in sample, mm2, and A, = area sensitivity of component, mm2 per percent. 9.2.3 Total the results and normalize to 100 %.

9.3 Normalization-Normalize the mole or liquid volume percent values obtained in 9.1 or 9.2 by multiplying each value by 100 and dividing by the sum of the original values. The sum of the original values should not differ from 100.0 % by more than 2.0 %. 10. Precision and Bias5 10.1 The data in Table 3 and Fig. 3 shall be used for

judging the acceptability of results (95 9% confidence) on samples containing less than 50 % propene. The data in Table 4 shall be used for judging the acceptability of results on samples containing more than 50 % propene. 1O. 1.1 Repeatabifity-The difference between successive test results, obtained by the same operator with the same apparatus under constant operating conditions on identical test material, would in the long run, in the normal and correct operation of the test method exceed the values shown in Table 3 or Fig. 3 and Table 4 in only one case in twenty. 1O. 1.2 Reproducibility-The difference between two single and independent results, obtained by different operators working in different laboratories on identical test material, in the normal and correct operation of the test method, exceed the values shown in Table 3 or Fig. - 3 and Table 4 in only one case in twenty. 10.2 Bias-Since there is no accepted reference material suitable for determining the bias for the procedure in this test method, no statement on bias is being made. 11. Keywords

5

1 1.1 analysis; liquified petroleum gas

The data from which this precision statement is based are not available.


=

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S T D * G P A S T D 21'4O-ENGL


APPENDIX (Nonmandatory Information)

X1. PARTITION COLUMNS X1.l The following four partition columns have been cooperatively tested and found suitable for use with materials given in the scope of this test method. X 1.1.1 Silicone 200/500 Column-This column separates ethane, propane, n-butane, isobutane, n-pentane, and isopentane and is therefore suitable for analyzing LP gases free from unsaturated hydrocarbons. X 1.1.2 Benzyl Cyanide-Silver Nitrate Column-This column separates isobutane, n-butane, the butenes, n-pentane and isopentane, and accordingly is best suited for use with LP gas butane containing unsaturated C, hydrocarbons. X 1.1.3 Hexamethylphosphoramide (HMPA) ColumnThis column separates ethane, propane, propene, isobutane,

n-butane, the butenes, n-pentane, and isopentane, and accordingly is suitable for use with all types of LP gases. X I. 1.4 Dimethylsufolane (DMS)-Benzyl Cyanide-Silver Nitrate Column-This column separates ail components in commercial LP gases. NOTEX 1 . 1 -There are commercial suppliers of gas chromatography equipment and columns who can make (and guarantee) that the columns they provide will meet the specifications (see 6.7 Columns) of this test method. NOTEX1.2: Warning-toxic. Precaution-See the product safety bulletins from the suppiier of the chemicals used in preparing these columns or before Benzyl Cyanidasilver Nitrate Column; XI. I .3 Hexamethylphosphoramide (HMPA) column, and X 1.1.4 Dimethylsufolane (DMS) Benzyl Cyanide-Silver Nitrate Column.

The American Society for Testing and Materials takes no position respecting the validity of any patent rights assmed in connection with any item mentioned in this standard. Users of this standard are expressiy advised that determination of the validity of any such patent rights, and the risk of infringement of such rights, are entirely their own responsibiiity.

--````,,```,,,```,`,,,,,`,,````-`-`,,`,,`,`,,`---

This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards and should be addressed to ASTM Headquarters. Your comments will receive careful consideration at a meeting of the responsible technical comminee, which you may attend. If you feel that your comments have not received a fair hearing you shouki make your views known to the ASTM Committee on Standards, 1916 Race St., Philadelphia, PA 19103.



S T D - G P A S T D ZLqO-ENGL 1997 M 382Lib77 0038527 2L2 M Designation: D 2713

- 91

An Amencan N a W Standard

Designation: 395/92

Standard Test Method for Dryness of Propane (Valve Freeze Method)’ This standard is issued under the fixed designation D 27 13; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon (6) indicates an editorial change since the last revision or reapproval.

1. Scope 1.1 This test method covers the measurement of the dryness of propane-type products such as, but not limited to, commercial propane (see Specification D 1835). NOTE1-This test method is not applicable to propane-type prod-

5. Apparatus 5.1 Propane Water Test Valve3-A specially constructed and calibrated valve manufactured solely for this test (Note 2). The valve has two open positions, a wide open position for flushing, and a small preset flow position for testing.

ucts containing antifreeze agents. However, the relative freeze times of such materials tested by this procedure may be an indication of the tendency of these products to cause freezing in pressure reducing regulators.

NOTE2-The propane water test valve is a precision instrument and it should be so treated. It should not be dropped, strained in any way, or disassembled, except to clean the filter in accordance with the manufacturer’s instructions. Valves suspected of being defective should be returned to the manufacturer for inspection, reconditioning or recalibration.

1.2 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user ofthis standard to establish appropriate safety and health practices and determine the appiicability of regulatory limitations prior to use. 1.3 The values stated in SI units are to be regarded as the standard. The values in parentheses are for information only. 2. Referenced Documents 2.1 ASTM Standards: D 1265 Practice for Sampling Liquefied Petroleum (LP) Gases2 D 183 5 Specification for Liquefied Petroleum (LP) Gases2 3. Summary of Test Method 3.1 A liquid-phase sample of the product to be tested is flowed through the propane water test valve to cool the valve body. After cooling, the test valve is partiaily closed to a small preset flow rate and the time required for the valve to freeze, and thus interrupt the normal flow, is recorded. The average observed time for several successive observations is recorded as the observed freeze time.

4. Significance and Use 4.1 This test is a functional test in which the water concentration in the product is related to product behavior characteristics in a pressure-reducing system of special design to arrive at a measure of product acceptability in common use applications. Experience has demonstrated that excessive water content (dissolved water) will cause freeze-up difficulties in pressure reducing systems. This test method is under the jurisdiction of ASTM Committee D2 on Petroleum Products and Lubricants and is the direct responsibility of Subcommittee W2.H on Liquified Petroleum Gas. Current edition approved March 15, 1991. Published July 1991. Originally published as D 27 13 - 68 T. Last previous edition D 2713 - 86. 2 Annual Book of ASTM Standards, Vol 05.01.

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5.2 Stop Watch. 5.3 Sample Cylinder, having a minimum capacity of 1 1.4

L (3 gai). 5.4 Cloth, dry, clean. 6. Sampling 6.1 The sensitivity of moisture test measurements to uncontrollable sampling errors is such as to warrant conducting all important tests at the propane supply source rather than on samples taken from the bulk supply. Referee tests should be conducted on the bulk supply. 6.2 If the test cannot be run by connecting the apparatus directly to the bulk propane supply, a sample can be taken into a sample cylinder having a minimum capacity of 1 1.4 L. In such cases, the sample shall be taken strictly in accordance with directions given in Practice D 1265.

7. Procedure 7.1 Connect (Note 3) the propane water test valve to the liquid line of the bulk product source or to the liquid phase connection of the sample cylinder described in 6.2, so that the body of the valve is horizontal and the outlet opening is aimed vertically upward. The valve should be positioned so that the internal surfaces of the outlet opening are clearly visible to the operator. Open the main valve on the sample source (Note 4) and set the valve on the test apparatus in the purge position. Purge the sample line and the apparatus for 15 s. Close the test valve for 2 or 3 s, open it for 2 or 3 s, close it for 2 or 3 s, and continue this intermittent opening and closing until a uniform frost cover has accumulated on the housing around the outlet of the test valve. Snap the valve closed to the test position and simultaneously start the stop watch. Stop the watch at the instant the liquid propane ceases to flow through the valve (Note 4). A list of supplies of LPGas freeze valves is available from ASTM.


S T D - G P A S T D 21‘40-ENGL

1997

3 8 2 4 b 9 9 0018528 157

4m D2713 NOTE3-Use only clean, dry pipe or metallic tubing for making this connection. Do not use mbber hose or plastic lined hose.

record the average time for three consecutive determinations

as the freeze-time. NOTE 5-Failure to purge the apparatus with the valve open to the purge position for about i 5 s between tests will give erroneous results. Purging assures that ice formed in the preset opening in the preceding test will be removed.

7.2 Sample pressure, at the inlet to the test valve, must not be more than 100 psi (690 kPa) above the vapor pressure of the product at the sample temperature. When sample source pressure is above this limit a liquid propane pressure regulator must be used to hold the pressure, at the inlet to the test valve, within this limit.

8. Report 8.1 If the valve does not freeze off within 60 s, report the product as “pass.”

NOTE4-The instant liquid propane stops flowing through the valve, frost will form on the internal surfaces of the valve outlet. The watch should be stopped at this instant. The operator is forewarned of this instant of stoppage if he will watch the frost line climb and roll over the lip of the valve outlet.

9. Precision and Bias 9.1 In the case of pass-fail data or results from other qualitative tests, no generally accepted method for determining precision or bias is currently available. NOTE6-Data from a series of tests conducted in 1967 indicate the following: At moisture levels of 14 and 26 ppm, all valves can be

7.3 Disregard the observed time for the initial freeze-off

mn.Quickly wipe the test valve outlet threads with a clean, dry cloth. Open the test valve to the purge position for about

expected to give freeze times over 3 min; at a moisture level of 49 ppm it can be expected that none of the valves will give freeze times over I8 s; at a moisture level of 93 ppm it can be expected that none of the valves wiil give freeze times over 5 s.

15 s to ensure the removal of ice from the preset opening. Repeat the operations as described in the trial run until three successive freeze-off times check each other to within +2 s. For freeze-off times of less than 1 min this may require as many as seven or eight test runs. If the freeze-off time on three consecutive test runs is 3 min or greater, the test on the product can be discontinued and the freeze-off time recorded as greater than 3 min. For freeze-off times shorter than 3 min

9.2 Bias-The procedure in Test Method D 2713 for measuring dryness of propane has no bias because the value of dryness is defined only in terms of this test method. 10. Keywords 10.1 dryness; propane.

The American Society for Testing and Materials takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the rlsk of infringement of such rights, are entirely their own responsibility. This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and it not revised, either reapproved or withdrawn. Your comments are invhed either for revision of this standard or for additional standards and should be addressed to ASTM Headquarters. Your comnients will receive careful consideration at a meeting of the responsibte tachnical committee, which you m y attend. /i you feel that your comments have not received a fair bearing you should make your views known to the ASTM CommMee on Standards, 1976 Race St.,Philadelphia, PA 19703.

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STD*GPA STD 2140-ENGL

#Tb

Designation: D 2784

1777

m

3824b77 0038527 075

- 92

m An American National Standard


Sulfur in Liquefied Petroleum Gases (Oxy-Hydrogen Burner or Lamp)' This standard is issued under the fixed designation D 2784: the number immediately following the designation indicates the year of original adoption or. in the case of revision. the year of last re\ ision. A number in parentheses indicates the year of last reapproval. A superscnpt epsilon ( e ) indicates an editorial change since the last revision or reapproval.

1 . Scope 1.1 This test method covers the determination of total sulfur in liquified petroleum gases containing more than 1 pg/g. Specimens should not contain more than 100 pg/g of halogens. 1.2 To attain the quantitative detectability that the method is capable of, stringent techniques must be employed and all possible sources of sulfur contamination must be eliminated. In particular. cleaning agents, such as common household detergents which contain sulfates, should be avoided. 1.3 The values given in acceptable metric units are to be regarded as the standard. 1.4 This standard does not purport to address all OJ the safety problems, if any. associated wirh its use. I t is the responsibilitj. of rhe user ofthis srandard to establish appro-

priare safer!, and healtli practices and determine the applicabilitj3 of regitlatorj, litnirations prior to use. 2. Referenced Documents 2.1 .4STM Slandards: D i56 Test Method for Saybolt Color of Petroleum Products (Saybolt Chromometer Method)' D 1265 Practice for Sampling Liquefied Petroleum (LP) Gases' D 1266 Test Method for Sulfur in Petroleum Products (Lamp Method)' D 1657 Test Method for Density or Relative Density of Light Hydrocarbons by Pressure Thermohydrometer' E I l Specification for Wire-Cloth Sieves for Testing Purposes' 2.2 Institute of Petroleum S~andard." IP I8 I Sampling Petroleum Gases, Including Liquefied Petroleum Gases --````,,```,,,```,`,,,,,`,,````-`-`,,`,,`,`,,`---

3. Summary of Test Method 3.1 The sample is burned in an oxy-hydrogen burner, or in a lamp in a closed system in a carbon dioxide-oxygen atmosphere. The latter is not recommended for trace quanI This test method i s under the jurisdiction of ASTM Committee D-2 on Petroleum Products and Lubricants and is the direct responsibility of Subcommittee W2.03 on Elemental Analysis. Current edition approved March IS. 1992. Published May 1992. Onginally published as D 2784 - 69 T. Last previous edition D 2784 - 89. Anniral Book ofAST.11 Siandurds. Vol 05.01. .4nniral Book O(AST.11 Slandards, Vol 14.02. Available from Amencan National Standards Institute. I I W. 42nd St.. 13th Floor. New York. NY 10036.

tities of sulfur due to the inordinately long combustion times needed. The oxides of sulfur are absorbed and oxidized to sulfuric acid in a hydrogen peroxide solution. The sulfate ions are then determined by either of the following finishes: 3.1.1 Barium Perchlorate Titration-The sulfate is titrated with barium perchlorate using a thorin-methylene blue mixed indicator. sulfate is precipitated as 3. I .2 Turbidimetric-The barium sulfate and the turbidity of a suspension of the precipitate is measured with a photometer. 4. Significance and Use 4.1 It is important to have the sulfur content of liquefied petroleum gases at low enough concentration to meet government regulations. The presence of sulfur can result in corrosion of metal surfaces. Sulfur can be poisonous to catalysts in subsequent processing.

5. Apparatus 5.1 Oxy-Hydrogen Combustion Assemblj-The two types listed below are recommended. Any combustion apparatus giving equivalent results, however, is satisfactory. 5.1.1 Wickbold-Tjpe Combustion Apparatirs.s as shown in Fig. 1. 5. i .2 Modtjìed Beckman Burner-Type Apparatus? as shown in Fig. 2. Each of the above types of apparatus shall consist of three parts: atomizer-burner, combustion chamber, and absorber with spray trap. A blowout safety port in the combustion chamber is desirable. The remainder of the apparatus shall consist of a suitable support stand with the necessary needle valves and flow meters for precise control of oxygen, hydrogen, and vacuum. 5.1.3 Safety Shield-A transparent shield shall be used to protect the operator in the event an explosive mixture is formed in the combustion chamber. 5.2 Apparatus for Lamp Cornbusrion: 5.2.1 Absorbers, Chimneys, and Spray Traps, as required are described in detail in Annex A3 of Test Method D 1266. 5.2.2 Mangold System, consisting of a vacuum manifold with regulating device, valves. etc. (Fig. 2 of Test Method D 1266) and a dual manifold (burner and chimney) supplying a gas mixture of approximately 70 % carbon dioxide (CO,) and 30 5% oxygen (O,) at regulated pressures. The gas Available from Koehler Instrument Co., h i . . 1595 Sycamore Ave.. Bohemia. N Y 117 16. with an all-stainless steel burner. or from Atlas Instrument Co.. 8902 E. 1 Iih St.. Tulsa, OK. For the latter. Hoke No. 993 combination flow meter-vahe assemblies should be substituted for those supplied. 'Available from Scientific Glassblowing Co.. P.O. Box 18353. Houston. TX 77023.

'



n-w-l Water

Committee on Analytical Reagents of the American Chemical Society, where such specifications are available.’ Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high purity to permit its use without lessening the accuracy of the determination. 6.2 Purity of Water-Unless otherwise indicated, references to water shall be understood to mean reagent water as defined by Types II or III of Specification D 1193. Water conforming to the following specification is required. Sulfate-free deionized water prepared by percolation of water through a column of mixed anion and cation exchange resins.

6.3 Standard Sulfate Solution (1 mL = 100 pg S)-Dilute 6.24 & 0.01 mL of 1 N sulfuric acid (H2S0,) with water to exactly 1 L. Check the dilution by titration against standard NaOH solution of about the same normality and adjust the concentration, if necessary, so that each millilitre of this solution is equivalent to 100 pg of sulfur. 6.4 Hydrogen (Warning-See Note 2), Carbon Dioxide (Warning-See Note 3), and Oxygen (Warning-See Note 4), meeting the requirement in Note 17.

LT-* 02 “2

1 -Atomizer-burner 2-Sample tube 3-Combustion chamber 4-Three-way stopcock

NOTE2: Warning-Extremely flammable. NOTE3: Warning-Gas may reduce oxygen available for breathing. NOTE4: Warning-Oxygen accelerates combustion.

5-Receiver

6-Spray

trap

FIG. 1 Flow Diagram of a Typical Oxy-Hydrogen Combustion

Apparatus

mixture in the chimney manifold shall be maintained at a nearly constant pressure of 1 to 2 cm of water and the burner manifold at approximately 20 cm of water. A suitable arrangement is shown in Fig. 2 of Test Method D 1266 and described in A3.6 of Annex A3 of Test Method D 1266, but any other similar system giving equivalent results can be used. 5.2.3 Blast Type Gas Burner, having dimensions given in Fig. 3. 5.3 Vacuum Source, having a capacity of at least 1200 L/h. If a vacuum pump is used, it should be protected by a suitable trap. 5.4 Corrosion-Resistant Metal Cylinder, 75-mL-It shall be tested at a pressure of 600 psig (4.14 MPa gage) and shall show no leaks when filled with air or nitrogen to this pressure and submerged in water. It shall be fitted with a needle valve for connection to the burner assembly. 5.5 Variable Transformer, 0-120 V, 750-W. 5.6 Carbon Dioxide Pressure Regulator-This regulator should be of a type that eliminates the refrigeration difficulties occurring with the pressure reduction of carbon d i ~ x i d e . ~

6. Reagents and Materials 6.1 Purity of Reagents-Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all reagents shall conform to the specifications of the

’

Victor Type SR 300, which has been found satisfactory for this application, is available from Victor Equipment Co., Controls Division, 2336 Auburn Blvd., Sacramento, CA 95821.

6.5 Scavenger-Rinse-Mix equal volumes of low-sulfur acetone and isopropanol. 6.6 Hydrogen Peroxide Solution ( 1.5 %) (1+ 19)-Mix 1 volume of concentrated hydrogen peroxide (H20, = 30 ’%) with 19 volumes of water. Store in a dark-colored, giassstoppered bottle. 7. Sampling Test Specimens and Test Units 7.1 Obtain the test unit in a container by the method conforming to the recommendations in Practice D 1265, or IP Method 181, 7.2 Evacuate a clean, dry 75-mL cylinder and weigh to the nearest 0.05 g. Connect the container to the inverted supply cylinder and introduce 24 to 40 g of the liquefied gas, taking care that the container does not become full of liquid. To prevent this, bleed off a small amount of the liquid phase of the material after filling but before reweighing. Reweigh the cylinder to 0.05 g. NOTE5-The 75-mL, corrosion-resistant metal vessel can be cleaned as follows: Remove the needle valve. Wash the interior of the vessel and valve, first with a sulfur-free hydrocarbon, such as n-pentane, and then wash with acetone. Dry the interior of the vessel with clean compressed air and rinse it with HCI (1+10). Rinse the interior with water until the wash water is neutral to a pH test paper. Wash the vessel with acetone and ailow to drain at least 10 min. Dry the vessel with a stream of clean, compressed air and reassemble. NOTE6-If the weight of liquefied petroleum gas is maintained below 45 g in a 75-mL container, the container cannot become full of liquid at room temperature.

* “Reagent Chemicals, American Chemical Society Specifications,” Am. Chemical Soc., Washington, DC.For suggestions on the testing of reagents not listed by the American Chemical Society, see “Reagent Chemicals and Standards,” by Joseph Rosin, D. Van Nostrand Co., Inc., New York, NY, and the “United States Pharmacopeia.”



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NOTE 1-A means for determining when to replace the exchange resins should be provided. Use of a simple electrical conductivity meter has been found satisfactory for this purpose.

ìNLET

FIG. 2

Trace Sulfur Apparatus Flow Diagram

0.05 Circulor Hole Pione

Surfoce)

46k

O0 All dimensions in millimetres

FIG. 3

8. Procedure for Combustion of Sample 8.1 Connect the sample cylinder with stainless steel tubing to the gas expansion valve. Attach to this another section of stainless steel tubing which runs to the vicinity of the burner. Make the final connection to the burner with sulfur-free rubber tubing. Wrap the expansion valve with heating tape and connect this to a variable transformer. Insert a thermometer between the heating tape and expansion valve so that the thermometer bulb is in contact with the valve body. See Fig. 4. 8.2 Turn on the variable transfomer and allow the expansion valve to reach 43°C (1 10°F). Alternatively the expansion valve may be placed in a suitable metal beaker and covered with water maintained at 11O"F. 8.3 Oxy-Hydrogen Combustion-Assemble the apparatus according to the manufacturer's directions (see also 14.1). Add to the absorber 25 mL of the hydrogen peroxide solution. NOTE7: Warning-Before attempting subsequent operations, the operator should ( 1 ) be aware of the various hazards that can exist

Blast-Type Gas Burner

Stainless Steel R e l i e f Valve

Stainless S t Connect ions

P

Regulating Valve Maintained at \ I O O F by Heoting Tope (4-f t Length, l 4 0 W , 4 5 V ) Controlled by a Variable Transformer FIG. 4

Burner Assembly for LPG



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Attach Burner Here

~

S T D - G P A S T D 23LiO-ENGL 3777 9 3824b77 0038532 b8T 9

4# through the improper use of hydrogen as a fuel, and (2) Recautionhave the safety shield in place.

8.3.1 Light the burner and insert into the combustion chamber. If necessary, readjust gas flows. Open the bottom valve of the sample cylinder. Slowly open the expansion valve until an optimum burning rate is achieved. 8.4 Lamp Combustion-Add to the absorber 25 mL of hydrogen peroxide solution. Assemble the chimney, absorber, and spray trap and connect to the C02-02 and vacuum manifold. Make the necessary vacuum adjustments (see 5.1 of Test Method D 1266). Set up a control blank absorber as in 5.3 of Test Method D 1266. 8.4.1 Open the bottom valve of the sample cylinder. Slowly crack the gas expansion valve. Light the bumer with an alcohol lamp, and insert the burner into the combustion chamber (chimney). 8.5 Bum a quantity of sample in accordance with Table 1. NOTE8-in burning materials with sulfur concentrations greater

~2784 of sulfur from the sample. Likewise subtract any sulfur obtained in the lamp combustion blank from the total figure. 8.1 I Disconnect the spray trap from the vacuum line and thoroughly rinse the spray trap and chimney with about 35 mL of distilled water, collecting the rinsings in the absorber. It is important that any materials clinging to these parts be transferred to the absorber to avoid low values for sulfur content. BARIUM PERCHLORATE TITRATION FINISH

9. Reagents 9.1 Ion-Free Water-Distill

deionized water and store in tightly capped, highdensity polyethylene bottles. 9.2 Hydrochloric Acid, Standard Alcoholic (O. 1 M)Dilute 20 mL of aqueous 0.5 M HCl with 80 mL of isopropanol. 9.3 Inhibited Thorin-Methylene Blue Mixed Indicator Solulion-The indicator is made up as two solutions and these mixed together in equal volumes once per week as follows:

than 50 pug, restrict sample sizes to give quantities that will not contain more than 250 pg of sulfur for the turbidimetric finish or more than 150 pg for the barium perchlorate finish. Alternatively, aliquots of the absorber solutions which do not contain more than these maximums can be used. NOTE9-Minor adjustment of the gas flow rates can be necessary to maintain those recommended by the manufacturer.

9.4 Fleisher S Methyl Purple Indicator Solution.l o 9.5 Barium Perchlorate (0.005 M)-Dissolve 1.95 g of barium perchlorate trihydrate" in 200 mL of water and add 800 mL of isopropanol. Adjust the apparent pH to about 3.5 with perchloric acid, using a pH meter. 9.6 Perchloric Acid," 70 %. 9.7 Sodium Hydroxide, Standard Solutions (0.03 M)Prepare by mixing 7 parts of water with 3 parts of standard O. 1 M sodium hydroxide (NaOH) solution. Concentrate 400 mL of 0.03 N NaOH solution by evaporating to 30 mL, and determine any sulfate present in accordance with Appendix A 1, Turbidimetric Procedure for Sulfate of Test Method D 1266. If sulfate is found, corrections must be made for any sulfur introduced by the reagent in the alkali titration following combustion. 9.8 Methylene Blue.

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8.6 After a suficient quantity of sample has been burned, turn the bottom valve of the cylinder off. Allow the remaining gas in the tubing and gas expansion valve to bum itself out. Turn the heat off on the gas expansion valve. Disconnect the tubing from the sample cylinder and reweigh the sample cylinder to the nearest 0.05 g. Leave the absorber solution in the assembled lamp unit. The same absorber solution will be used for the scavenger-rinse burning. Allow the expansion valve to cool to ambient temperature. 8.7 If the oxy-hydrogen burner permits, flush the tubing and valve with 10 mL of scavenger-rinse and bum without disconnecting the tubing. Otherwise disconnect the tubing and bum in the normal liquid mode. For the lamp burning collect the rinsings in a standard lamp sulfur (see Test Method D 1266) flask. Insert a standard burner equipped with a wick into the flask and carry out the combustion as described in Section 7 of Test Method D 1266. 8.8 For the oxy-hydrogen burners, when all of the rinsings are consumed, shut down the burner as recommended by the manufacturer. 8.9 After the rinsings have been burned in the lamp, remove it, turn off the C02-02 supply, and turn off the vacuum pump. 8.10 For oxy-hydrogen blank determinations bum a hydrocarbon stock with a very low or nondetectable sulfur content. Make at least two of these prior to the analysis of samples with trace sulfur contents to ensure that the blanks are small and constant. Subtract from the total sulfur figures any blank so obtained. The remainder is the net micrograms

Solution A: 0.8 g thorin? 0.29 g potassium bromate, water to make 500 mL, Solution B O. 16 g methylene blue, 0.2 mL of 0.5 M HCl, water to make 500 mL.

TABLE 1 Sample Sizes

10. Preparation of Working Curve 10.1 Into separate 30-mL beakers pipet each of the aliquots of the standard sulfate solution given in Table 2. See 6.3. To each aliquot add sufficient water to make 3.4 mL, 12 mL of isopropanol (total volume 15.4 mL) and 3 drops of mixed thorin-methylene blue indicator solution. Titrate as indicated below. For each sulfur level given in Table 2, titrate three of the corresponding aliquots. Plot the millilitres of titrant used versus micrograms of sulfur. Draw the best straight line through points. Check at least two points on the curved at least every 10 days.

~~

SuMir Content, ppm

S a m p Size, g Turbidimetric Finish

Barium Perchlorate Finish

45 20 5

30

1 to 5 5 to 10 10 to 50

Available from Hach Chemical Co., Ama. IA. 'OAvailable from Reisher Chemical Co., Benjamin Franklin Station. Washington,DC 20044. ''Ava¡lable from G. Frederick, Smith Chemical Co., P.O.Box 23344, Columbus. OH 43223.

10

3



~~

TURBIDIMETRIC FINISH

Sulfur, gg AligUOtS, rnL

0.40

0.80

1.20

~

2.40

300 3.00

I I . Procedure for Analysis of Solutions 1 1.1 Quantitatively transfer the absorber contents to a 500-mL Erlenmeyer flask, using ion-free water for rinsing. Add 2 drops of Fleisher’s methyl purple indicator solution to this solution and titrate to a faint green end point with 0.03 M NaOH solution (Note 12). Add i mL more of the 0.03 M NaOH solution to the solution and reduce the volume to 2 to 3 mL by evaporation on a hot plate in sulfate-free environment. (Warning-see Note 11): DO NOT BOIL DRY. Cool the solution to room temperature and measure its volume in a 10-mL graduate (Note 12). Adjust the volume to 3.0 mL by adding ion-free water. NOTE10: Warning-Do not boil. NOTE1 I-The volume of sodium hydroxide should not exceed 2 mL. More indicates that the sulfur or halogen content is excessive or that there is a serious air leak in the apparatus. NOTE12-For high or completely unknown sulfur contents, the concentrated absorbent can be quantitatively transferred to a 5-mL volumetric flask, adjusted to 5 mL, and aliquots used. Each aliquot is then subsequently made up to 3 mL as in 1I. I. Continue as in I 1.2.

11.2 Transfer the absorbent to a 30-mL beaker, rinse the graduate and the 500-mL boiling flask successively with two 6-mL portions of isopropanol, and add the rinses to the beaker. 1 1.3 Pipet 0.40 mL of the standard sulfate solution (40 pg of sulfur) into the beaker. Add 2 drops of the thorinmethylene blue mixed indicator solution. Adjust the resultant gray-green color by adding 0.1 M HC1 dropwise to the solution until the color changes to bright green. 1 1.4 The 2-mL buret containing standard barium perchlorate should have its tip positioned just below the surface of the solution in the beaker. The solution must be stirred by a small bar on a magnetic stirrer or with a small propeller stirrer. A white background and good white light may be helpful in obtaining a precise end point. Add the barium reagent at a steady rate of O. 1 mL in 5 (A1) s until the end point is indicated by a rapid, though slight, color change from green to a bluish gray (Note 13). Shut off the buret at the point of greatest rate of color change (Note 14). NOTE 13-It is helpful to match end point colors with solutions saved from prior standardization titrations performed within the last 15 min and weil stirred to prevent drop-out of the colored barium sulfate precipitate. People having a low red-green color sensitivity find that using the blue light of Method D 156, sharpens the end point very considerably. NOTE 14-The end point can be. checked by again adding 40 pg of sulfur (0.4 mL standard sulfuric acid) and retitrating to the end point.

1 1.5 From the working curve, find the total sulfur titrated to the nearest 1 pg. Subtract the 40 pg added. 11.6 For blank determinations, repeat the operations in 8.3 and 8.7, and burn a hydrocarbon stock with a very low or nondetectable sulfur content. Burn for the same length of time as the sample in the normal liquid mode. Subtract from the sulfur figures in 11.5 any blank so obtained. This is the net micrograms of sulfur from the sample.

12. Apparatus

12.1 Photometer-Preferably a spectrophotometer having an effective band width of about 50 nm, and equipped with a blue-sensitive phototube for use at 450 nm, or alternatively a filter photometer equipped with a color filter having a maximum transmission at approximately 450 nm. 12.2 Absorption Cells, having an optical path length of 5 cm. With use the cells may become coated with a film. To remove this film, wash the cells with a detergent, using a soft brush. After cleaning, rinse thoroughly with water. NOTE15-The procedure as written assumes an absorbance change of about O. 10 for each 100 pg of sulfur in 50 mL of solution measured in a 5-cm cell. Photometers employing cells of shorter optical paths will not give the precision of measurement stated in this method.

12.3 Scoop, capable of dispensing 0.30 k 0.01 g of barium chloride dihydrate as specified in 13.2. 13. Reagents 13.1 Alcohol-Glycerin Mixture-Mix 2 volumes of denatured ethyl alcohol conforming to Formula No. 3A of the U.S. Bureau of Internal Revenue or ethyl alcohol (99 % by volume) with 1 volume of glycerin. 13.2 Barium Chloride Dihydrate (BaCl, 2H,O)-Crystals passing a 20-mesh (850-pm) sieve and retained on a 30-mesh (600-pm) sieve conforming to Specification E 1 1. NOTE16-The crystal size of the BaC1,.2H20 is an important variable that affects the development of turbidity.

13.3 Hydrochloric Acid ( 1+ 12)-Add 77 mL of concentrated hydrochloric acid (HC1, relative density 1.19) to a 1-L volumetric flask and dilute to the mark with water. 14. Calibration

14.1 Only by the most scrupulous care and attention to details can reliable results be obtained by this method. Before using new glassware and thereafter as required, clean the glassware with concentrated nitric acid. Rinse three times with tap water and follow with three rinses of deionized water. Reserve the glassware for use in this method alone. 14.2 Into 50-mL volumetric flasks introduce, by means of the buret, 0.25, 0.50, 0.75, 1.00, 1.50, 2.00, 3.00, and 5.00 mL of standard sulfate solution (1 mL = 100 pg S ) . See 6.3. Add 3.0 mL of HCl (1+12) to each flask, dilute to volume with water, and mix thoroughly. Prepare a reagent blank standard in a similar way, omitting the standard sulfate. 14.3 Pour the entire contents of each flask into a 100-mL beaker. Add by means of a pipet 10 f 0.1 mL of alcoholglycerin mixture and mix for 3 min on the magnetic stirrer. Select a stirring speed just below that which might cause loss of sample through splashing. Maintain this speed throughout the entire procedure. 14.4 Allow the solution to stand undisturbed for 4 min. Transfer to an absorption cell and measure the initial absorbance, using water as reference. 14.5 Return the solution to the beaker and add 0.30 f 0.01 g of BaCl,-2H,O crystals, either by weighing this amount or by using the scoop. Stir with the magnetic stirrer for exactly 3 min. Allow to stand for an additional 4 min, transfer to the cell, and again measure the absorbance relative to water.



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Preparation of Working Curve 40 80 120 240

TABLE 2

15.5 Convert net absorbance to micrograms of sulfur by using the calibration curve.

14.6 Following steps described in 14.3, 14.4, and 14.5, obtain a reagent blank reading by subtracting the initial absorbance of the reagent blank standard from that obtained after addition of BaC12.2H20. This reading should not exceed 0.005. 14.7 Obtain the net absorbance for each standard by subtracting the initial absorbance and reagent blank reading from the absorbance obtained in accordance with 14.5. Plot the net absorbance of each standard against micrograms of sulfur contained in 50 mL of solution and draw a smooth curve through the points. 14.8 To detect possible shifts, check the calibration curve daily by making single determinations.

16. Calculation 16.1 Calculate the amount of sulfur in the sample as follows: Sulfur content, pg/g = A/ W (1) where: A = micrograms of sulfur as obtained in 1 1.6 or 15.6, and W = grams of sample burned. 16.1. I Round the result of the test to the nearest 1 pg/g of sulfur. 16.2 Alternatively calculate the concentration in units of grains of total sulfur per io0 ft3 as follows: R (for propane) = 0.083s R (for butane) = O. 1 1 1S (2) R (for propane-butane mixtures) = S[0.366(G - 0.5077) + 0.0831 where: R = grains of total sulfur per 100 ft3 of gas at 15.6'C (60'F) and 0.10132 MPa (760 mm) Hg, S = sulfur content, pg/g, and G = relative density of the mixture at 15.6/15.6'C (60/60'F).

15. Procedure for Analysis of Absorber Solutions

15.1 Drain the absorber solution into a 250-mL beaker and quantitatively rinse the absorber collecting the rinsings in the beaker. 15.2 Reduce the volume of the absorber solutions to about 25 mL by evaporation on a hot plate. Quantitatively transfer the resultant solution to a 50-mL volumetric flask, rinsing the beaker with several small portions of water. Add 3 mL of HCl (1+ 12) to the flask, make up to volume with water, and mix thoroughly. 15.3 Into a 100-mL beaker pour the entire contents of the 50-mL volumetric flask containing the solution to be analyzed. Proceed as directed in 14.3, 14.4, and 14.5.

NOTE18-The derivatives of constants used in the above equations are based on the following properties of propane and butane: Specific volume for propane (of the real gas at 60'F and 14.696 psia), ft3/lb of gas Specific volume for butane (same conditions as above)

6.3120

NOTE 19-If the relative density of the mixture is not known, determine it by Test Method D 1657. NOTE20-Multiply by 2.2883 to convert grains per cubic foot to grams per cubic metre. Multiply by 35.31 to convert grains per cubic foot to grams per cubic metre.

NOTE17-Should the blank reading exceed 0.020, the precision obtainable will be impaired. If so. make an analysis of the reagents alone to determine whether the atmosphere or reagents are at fault. Place 30 mL of the H202( i .5 %) in the 50-mL volumetric flask, dilute to the mark with HCI (1 +2 1 5 ) , and proceed as described in 14.6. If this reagent blank reading exceeds 0.010, results should not be Considered reliable.

17. Precision and Bias 17.1 The precision of this test method has not been determined. The responsible subcommittee is attempting to attract volunteers for an interlaboratory study. 17.2 The bias of this test method cannot be determined since appropriate reference material containing a known level of sulfur in liquified petroleum gases is not available.

15.4 Obtain the net absorbance of the analysis solution by subtracting the initial absorbance and the net absorbance for the oxy-hydrogen combustion blank or the lamp combustion (depending upon the apparatus used for combustion) from that obtained after the addition of BaCI, 2H,O.

-

The American Society lor Testing and Materials takes no position respecting the validity of any patent rights asseI1ed in connection with any item mentioned in this standard. Users ot this standard are expressly advised that determination ot the validity d any such patent rights, and the risk of infringement of such rights, are entirely their own responsibility. This standard is subject to revision at any time by the respsibie technical commirree and must be reviewed every tive years and 1not revised, either reapproved or withdrawn. Your comments are invit8d either for revision of this standard 01 for additional standards and should be addressed to ASTM Headquarters. Your comments wi// receive careful consideration at a meeting of the responsible technical committee, which you may attend. If you feel that your comments have not received a lair hearing you should make your views known to the ASTM Commirree on Standards, 7976 Race Sr.. Philadelphia, PA 19703.


8.45 I5

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S T D - G P A STD 2140-ENGL 1997

3 8 2 4 b 9 9 0038535 377

=

GPA STANDARD 2174-93 OBTAINING LIQUID HYDROCARBON SAMPLES FOR ANALYSIS BY GAS CHROMATOGRAPHY 1. SCOPE 1.1 The specific purpose of this method is to describe the equipment and procedures for obtaining representative samples of natural gas liquids and the subsequent preparation of those samples for laboratory analysis by gas chromatography. The procedures described in this method may be used for obtaining samples for analysis by methods other than gas chromatography. A S A M P L E P R O B E M U S T BE U S E D TO O B T A I N A REPRESENTATIVE SAMPLE. 2. OUTLINE OF METHODS

2.1 A hydrocarbon fluid sample is transferred under pressure from a source into a sample container by one of the following methods: a. Floating Piston Cylinder Method b. Water Displacement Method 1 (total H 2 0 removal replaced by hydrocarbons; 20% displaced for outage)

at the bottom. It is strongly recommended that the samples be obtained under the supervision of a person knowledgeable i n the phase behavior of hydrocarbon systems and experienced in all sampling operations.

3.4 T h e s c o p e of t h i s method does not include recommendations for the location of the sampling point in a line or vessel, although the importance of the proper sampling location cannot be overemphasized. 3.5 A certain amount of information about a sample is necessary before it can be intelligently handled in the laboratory. Essential information includes the sample source, sample date, cylinder identification, sample source pressure and temperature, ambient temperature, type of analysis required, and the sampling method used. There may be additional related facts such as field-determined results and operating conditions which will assist in the evaluation of the analytical data. This information must accompany the filled sample cylinder.

- 80%

c. Water Displacement Method 2 (partial H 2 0 removal

-

70% replaced by hydrocarbons; 20% displaced for outage; 10% remaining in cylinder) d. Ethylene Glycol Displacement Method (total glycol removal - 80% replaced by hydrocarbons; 20% displaced for outage)

NOTE 1: Methods b, C, and d may not be aPP1icable to the analysis of certain samples containing reactive non-hydrocarbons such as sulfur compounds, carbon dioxide, etc.

3. GENERAL INFORMATION

3.1 The objective of any sampling operation is to secure, in a suitable container, an adequate portion of a hydrocarbon fluid under pressure, having the same composition as the stream being sampled. 3.2 Particular emphasis should be given to the necessity of obtaining accurate, representative samples for analysis since analyses, regardless of the care and accuracy of the laboratory tests, may be useless if the samples are not valid.

3.3 It is not possible, nor is it the intent of this method, to provide a procedure that will be applicable for all sampling situations. T h e s a m p l e s o u r c e h e r e is assumed t o b e a homogeneous, single-phase liquid. All samples must be obtained using a probe designed to secure product from the center one-third of the flowing stream. The location of the probe fitting should be on the top or side of the line rather than

3.6 If the hydrocarbon fluid samples are to be transported by common carrier within the United States, the sample containers must meet the specifications of and be labeled and packaged according to the Hazardous Materials Regulations of the Department of Transportation.

3.7 This method assumes all procedures begin with clean, leak-free sample cylinders. Cylinders must be thoroughly cleaned prior to sampling with an appropriate volatile solvent or by following - manufacturers’ recommendations. The use of detergentlwater solutions or steam is not recommended for the cleaning of floating piston cylinders. 3.8 For floating piston cylinders, it is desirable in most cases to use an “inert” charge gas for the piston cylinder which is not present in the sample so that a leak in the cylinder itself can be easily detected during the analysis. The use of natural gas as a back pressure fluid is not recommended because a leak across the piston may result in compromising the sample with hydrocarbons (or other components) which were not actually present at the source. A method to insure a leak-free cylinder is to pressure test both sides of the piston cylinder. This is accomplished by pressurizing the displacement chamber with inert gas to a typical operating pressure with valve C opened (see Fig. i). Next, close valves C and D and note the pressure reading-on gauge N. After a period of five minutes, a decrease in pressure as indicated at gauge N and a corresponding increase in pressure at gauge M would indicate a leak across the piston. A pressure drop only at gauge N indicates a leaky fitting, valve, gauge, or rupture disc. The inert gas should be removed from the displacement end and the above procedure repeated for the sample side. It is also possible to analyze the inert gas side of

37 --````,,```,,,```,`,,,,,`,,````-`-`,,`,,`,`,,`---



SAMPLE SOURCE

C

PROBE

R1

H

L

SAMPLE

FLOATING PISTON

INERT GAS

I

CYLINDER+

N

INDICATOR ROD

Figure 1. Typical Visual Indicator Sampling System

design) may prevent the flashed product from returning original homogeneous mixture.

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the cylinder to determine hydrocarbon concentration if leakage occurs in that direction. Cylinders should be tcstcd at least on an annual basis.

3.9 Carc must be exercised when sampling liquids having a vapor pressure higher than atmospheric pressure to prevent flashing of lighter components when transferring product from the source to a sample cylinder, or from a primary sample cylinder to a secondary cylinder. For floating piston cylinders, precautions should also be taken to ensure that the inert gas pressure in the piston cylinder never drops below the sampling pressure or the product’s vapor pressure at the existing source temperature, thus preventing flashing of the sample. Theoretically, the product in the vapor state could be returned to liquid phase, but the physical restrictions of the piston cylinder (e.g., rupture disc, valve dead space, and stirring assembly

3.10 Duplicate Samples

3.10.1 When resampling is difficult or impossible, it is advisable to take duplicate samples as a precaution against accidental loss. These duplicate samples must be taken using the same sampling method and from the same sampling location. The sample sequence should be noted on thc sample information a& t.! 4. APPARATUS

4.1 Sample Containers


LO the


S T D * G P A STD ZLqO-ENGL 1777

3824b77 0038537 L b 3

4.1.1 Floating Piston Cylinders

4.1.1.2 The cylinder itself contains a moving piston equipped with O-rings, teflon rings, or other devices to effect a leak-free seal between the sample and the pressurizing fluid while allowing it to move freely within the cylinder. The use of guide rings is recommended to assure smooth piston travel. The piston and sealing device must be non-reactive to the sample, the pressurizing fluid, the cleaning solvents, and expected corrodants. TIOR Some types of lubricating fluids will absorb appreciable amounts of the Cd+ fraction from the gas being sampled, thus compromising the integrity of the sample. It is recommended that non-absorbing lubricating greases, such as, but not limited to DuPont's Krytox AC or AD,be wed to prevent this difficulty. Further details regarding non-absorbing lubricating greases can be obtained from the piston cylinder man ufac turers.

4.1.1.3 All valves and safety devices must meet the appropriate material and pressure requirements for safe design. The pressure reliefs may be of spring or rupture disc types. These allow a partial or complete loss of contents due to thermal expansion or over-pressurization. Should relieving occur, the sample should be considered compromised. 4.1.1.4 Some piston-type cylinders are fabricated from nonmagnetic materials such as the 300 series stainless steel. The piston likewise is fabricated of stainless steel but has magnets attached to the precharge side of the piston. As the piston moves the'length of the cylinder, the magnetic field generated by the magnets flips a series of bi-colored flags. This system, or systems of similar configuration, indicates the piston position and the volume of product in the cylinder. 4.1.1.5 Some piston-type cylinders are fabricated with a rod attached to the piston which extends through the end cap on the inert gas back pressure chamber with appropriate sealing devices to prevent the inen gas from leaking. The traveling rod provides an indication of the piston position and the volume of the product sample in the cylinder. Again, some variations of this style may exist.

4.1.1.6 Other types of floating piston cylinders are available which have no visuai method of determining the sample volume directly. For these cylinders, a displacement cylinder, cylinder Y (Fig. 2), is fabricated from metal tubing. This cylinder must be designed to meet the same pressure requirements as the piston cylinder and have a volume of no more than 80 percent oí the pressurizing volume of the piston cylinder. 4.1.2 Double Valve Cylinders 4.1.2.1 Metal sample containers of a type which insure maximum safety and which are corrosion resistant to the product being sampled should be used. Stainless steel containers are recommended to minimize problems of surface adsorption of heavy components (hexanes and heavier components) and to minimize the reaction of carbon dioxide or other contaminants with the container. Sample containers and valves must have a working pressure equal to or exceeding the maximum pressure anticipated in sampling, storage, or transportation of the sample container. Soft-seated valves are preferable to those having metai-to-metai seats. The size of the container depends upon the amount of sample required for the laboratory tests to be performed. NOTE 2: DOT regulations regarding the use of pressure relief devices on these cylinders must be followed.

4.2 Sample Transfer System 4.2.1 Transfer lines, valves, and gauges in the transfer system shall be designed consistent with maximum anticipated pressure and be resistant to all expected corrodants. (Stainless steel is preferred.) The transfer lines should have a minimum diameter of 114 inch (6.35 mm) and be as short as is practical. The use of filters and dryers is discouraged. 4.3 Composite Sampling Mechanism 4.3.1 A composite sampling mechanism is a device which is used to obtain a representative sample from a flowing product stream over a given period of time. The unit consists of a sample probe, either a flow-through sample injection valve, whether automatic or manual (see Figures 3 and 4) or a probemounted sample pump (Fig. 5) and utilizes a floating piston cylinder as its collection chamber. The system must include a method to mix the product sample in the collection chamber. This is necessary regardless of whether the original floating piston cylinder is removed and used for laboratory analysis or a transfer of the product sample is made into a secondary cylinder as described herein. (Figure 6 depicts a typical automatic sampler and the various parts required. Figure 5 depicts a typical proportional sampler using an injection pump and the vanous parts required.)



--````,,```,,,```,`,,,,,`,,````-`-`,,`,,`,`,,`---

4.1.1.1 The container required for this method is constructed of metal tubing, honed and polished on the inside surface. The cylinder is preferably closed with removable end caps to provide access to remove and service the moving piston. The end caps are drilled and tapped for valves, gauges, and relief valves. The cylinder is designed consistent with the maximum pressure anticipated during sampling and to be nonreactive to materials being sampled, the pressurizing fluid, the cleaning solvents and the expected corrodants. The volume of the cylinder will depend on the amount of sample needed for the laboratory analysis.

UMPLE

PISTON INERT GAS --````,,```,,,```,`,,,,,`,,````-`-`,,`,,`,`,,`---

h

CX!NDER

Y

AIR (ATMOSPH E RIC PRESSURE)

Figure 2. Displacement Cylinder Sampling System

4.4 Sample Filters

5. SAMPLING PROCEDURES

4.4.1 The sample filter is an optional device used to protect the sampling valve from scoring due to h e presence of foreign contaminants such as metal shavings, dirt, etc., in a NGL sample. The filter should be of a small total volume, of an inline-type design, and contain a replaceable/disposable element.

5.1 Floating Piston Cylinder Method

5.1.1 Technique of using a cylinder equipped with visual indicatorfor liquid phase samples of “spot” or “instantaneous” type (see Figure 1 )

CAUTION; A filter may introduce error if not handled properly. The filter should be clean and free of any residual product from previous samples so that a buildup of heavy-end hydrocarbon components does not result. (This may be accomplished by a heatinglcmling process or inert gas purge, etc.) The filter element should be 15 micron size or larger so that during the purging process NGL is not flashed, causing fractionation and bubble formation.

5.1.1.1 With sample side of cylinder evacuated (from cleaning operation) and valve C open, fill displacement end with inert gas to a pressure at least 10 psi (69 P a ) above sampling pressure. Close valve D.

5.1.1.2 Open valve A at sample source and thoroughly blow

out any accumulated material. Close valve A at sample source.



I

?I

i

r ?? i

-

-+- -

---

-

4-73

S T R U M SAMPLE-

/

PROBE ~~

~~

~

Figure 3. Typical Sample Probe Installation on Orifice Flange

Figure 4. Typical Sample Probe Installation for a Pump

5.1.1.3 Connect piston cylinder to sampling source at valve A.

5.1.1.8 Close valves D, C, and A in that order. Open valve B to release pressure on the sample line. Disconnect the cylinder from sample source.

5.1.1.4 With valves B and C closed, open source valve A to full open position. Observe sample pressure on gauge L. Crack

valve B and fitting at valve C to purge line. Do not allow pressure L to drop below original sample pressure. Discontinue purging after a sufficient time and only when liquid product is present. If the product flashes without leaving a liquid residue at valve B and the fitting at valve C, the operator must use judgment in determining when to discontinue purging. Close valve B and tighten fitting at valve C.

5.1.1.9 Do not take outage or reduce pressure on piston cylinder. Check valves C and D for leaks, cap valves to protect threads, prepare sample information tag and box for transportation as per Department of Transportation or applicable requirements.

5.1.2 Technique of using cylinder not equipped with visual indicator for liquid phase samples, via displacement cylinder, of ?spot? or ?instantaneous? type (see Figure 2)

NOTE 3: If the diameter of the indicator rod is of significant size

compared to the piston, then the pressure on the inert gas side will be

5.1.2.1 With sample side of the piston cylinder evacuated (from cleaning operation) and valve C open, fill displacement end with inert gas to a pressure at least 10 psi (69 kPa) above sampling pressure. Close valve D.

slightly higher than the sample side, Le., gauge N will read higher than gauges L and M. This comment applies to all subsequent comments regarding equal pressures on gauges L.M and N.

5.1.1.5 Adjust pressure on gauge N to equal pressure L by releasing adequate inert gas through valve D.

5.1.2.2 Open valve A at sample source and thoroughly blow out any accumulated material. Close valve A at sample sourcc.

5.1.1.6 With valve D closed, slowly open valve C completely. There should be no pressure change on gauge N and pressure at gauges L, M and N should all be equal.

5.1.2.3 Connect piston cylinder X to sample source at valve A and displacement cylinder Y to piston cylinder. Displacement cylinder Y should be filled with air at atmospheric pressure. For proper cylinder sizing refer to Section 4.1.1.6.

5.1.1.7 Partially open valve D,slowly allowing inert gas to vent to the atmosphere. To prevent flashing, do not allow pressure M to drop below sampling pressure. Continue the operation until the indicator designates the cylinder contains 80% by volume of product (following manufacturer?s instructions).

5.1.2.4 With valves B and C closed, open sample source valve A to full open position. Observe sample source pressure on gauge L. Crack valve B and fitting at valve C to purge line. Do not allow pressure L to drop below original sample pressure.

--````,,```,,,```,`,,,,,`,,````-`-`,,`,,`,`,,`---



--````,,```,,,```,`,,,,,`,,````-`-`,,`,,`,`,,`---

Product flow meter

Minimum 5 Diameters

/

r

Center-stream sample probe

injection pump

totalizer

___ f

1 P P ~

I

I I

4

:

Pulse divider circuit

i 1 puise per "X" bbis.

I

:

114" to îJ2"

tubing

I

1

I I

I

AC - - - - Power

_---

Power

I

I I

Pressure recomer

I

Pressure regulator

I

k4

Pressure

Check valve

Sample transfer tap

Bleed valve

Figure 5. Typical Proportional Sampler Using an Injection Pump



PRODUCT FLOW METER

;L--imTfp STREAM SAMPLE

3

TOTALIZER

1 ) -

i

1 PPB

AC POWER

' i

r---

c

1 PULSE PER "x" BELS. --)---

POWER INTERPOSER

PROBE

A

FILTER

I

Y

DIVIDER

I

3

--

FLOW-TH RU SAMPLE INJECTION VALVE

i

--_--

I I

4

x-

PRESSURE TUBING

RECORDER

7

I INERT GAS PISTON SAMPLE

a. SAMPLE TRANSFER TAP 7 PRESSURE SUPPLY

VALVE

SAMPLE MIXING DEVICE

Figure 6. Typical Automatic Proportional Sampler



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K

5.1.3.4 All samples must be obtained using a probe. (Refer to Section 3.3 for specifications and location.) A bypass device that causes a differential pressure, such as an orifice plate or a small pump, is used to supply fresh liquid to a location for filling the sample container, either manually or by use of sample injection valves. The bypass sample line utilizes short lines of a small diameter connecting the fresh sample source to the floating piston cylinder receiver (see Figures 3 and 4).

Discontinue purging after a sufficient time and only when liquid product is present. if the product flashes without leaving a liquid residue at valve B and the fitting at valve C, the operator must use judgment in determining when to discontinue purging. Close valve B and tighten fitting at valve C. 5.1.2.5 With valve E closed, open valve D and observe pressure on gauge N. Adjust pressure N to equal pressure L by slowly venting inert gas through valve E. Close valve E.

5.1.3.5 The floating piston cylinder should be connected to the purged sample line via the composite sampling device. Inert gas pressure or appropriate pressurizing fluid should be applied to the cylinder to force the piston to the starting end of the sampling cylinder. The inert gas pressure should be maintaincd at a pressure which exceeds by 200 psi (1379 kPa) the equilibrium vapor pressure of the fluid sampled under expected varying temperature conditions. At pressure differences less than 200 psi (1379 kPa) the chance for erroneous samples increases.

5.1.2.6 With valve E closed, slowly open valve C to full open position. There should be no pressure change indicated on gauge N and pressure at gauges L, M and N should all be equal. 5.1.2.7 Close valve D. Open valve E and properly vent pressure through valve F. Close valve F. 5.1.2.8 Slowly open valve D, allowing inert gas from cylinder X to flow into cylinder Y. Observe gauge M so as not to allow pressure M to drop. Continue operation until-pressure of all three gauges equalizes. At this point, a volume equal to cylinder Y has been displaced into cylinder X by the product sample. Sample cylinder X now contains 80% by volume of sample, leaving sufficient inert gas space to insure safe storage and transport.

5.1.3.6 The automatic sample injection valves will require adjusting to obtain incremental samples at a rate such that the floating piston cylinder will have adequate capacity to hold the sample during its period of sampling. Care should be exercised to prevent overfilling of the sample container so that relieving does not occur, thus changing the composition of the sample and creating a serious safety hazard.

5.1.2.9 Close valves D, C, and A in that order. Open valves B and F. Disconnect displacement cylinder Y. Disconnect piston cylinder X from sample source.

5.1.3.7 Increasing or decreasing the volume of sample desired can be accomplished by changing the volume of the incremental sample obtained with the injection valve and/or by changing the frequency of the proportioning device which controls the injection valve.

5.1.2.10 Do not take outage or reduce pressure on piston cylinder X. Check valves C and D for leaks, cap valves to protect threads, and prepare sample information tag and box for transport as per Department of Transportation or applicable requirements.

5.1.3.8 The sample obtained by the sampler apparatus and stored in the floating piston cylinder must be mixed thoroughly by either a mechanical device or a liquid pump and circulating system,

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5.1.3 Technique of using floating piston cylinders for liquid phase samples of “composite” type via manual or automatic systems (see Figures 5 and 6 )

5.1.3.9 The floating piston cylinder used i n the above system may be removed from the composite sampling device after the desired product has been sampled.

5.1.3.1 Automatic proportional samplers take small samples of the flowing stream proportional to the flow rate. Time increments may be used only when the flow rate is consmt.

CAUTION: Under no circumtances should the cylindcr be filled beyond 80% of its capacity with sample.

5.1.3.2 Thorough purging of sample lines, pumps and connections to the sample cylinder is necessary to avoid contamination of the sample. Sampler systems should be designed to minimize stagnant areas which could result in the sample not being representative of the fluid source.

5.1.3.10 Do not take outage or reduce pressure on the cylinder. Check valves for leaks, cap valves to protect threads, and prepare sample information tag and box for transport as per Department of Transportation or applicable requiremenis.

5.1.3.3 Precautions shall be taken to avoid vaporization in sample loop lines when operating near the equilibrium pressure of the liquid. In some instances, it may be necessary to insulate the sample line and sample container, or control the pressure or temperature of sample containers containing volatile materials.

5.1.3.11 If it is not possible to disconnect the primary floating piston cylinder from the automatic system, the sample may be transferred to a secondary floating piston cylinder. Once the sample in the primary cylinder is adequately mixed, proceed



S T D - G P A S T D ZLVO-ENGL 1997

as in step 5.1.1, treating the primary cylinder as a flowing source. (In this particular transfer situation, as sample is withdrawn, the master sample container will partially depressurize. The product vapor pressure al the existing master sampler temperature must be maintained or exceeded to prevent flashing.) 5.2 WaferDisplacement and Ethylene Glycol Displacement Methods - Total displacement

5.2.1 A double valve sample cylinder filled with clean ethylene glycol or water and a vessel to measure the displaced liquid are required for these two methods (see Figure 7).

3824b99 0038543 4b5

Ethylene glycol must be the glycol t y p used. Water must have a pH between 5.0 and 7.0. Water with a pH greater than 7.0 must be acidified to bring the pH within the proper range. (0.1 N H2SO4 is a satisfactory acid solution.) 5.2.2 The total volume of the sample cylinder must be found, then 80% of the total volume should be calculated. (For example, if the total volume of the cylinder is 500 ml, then 80% of the total volume is 400 mi.)

5.2.3 Open valve A at sample source and thoroughly blow out any accumulated material. Close valve A at sample source.

L

SAMPLE SOURCE

["i rl CYLINDER

--````,,```,,,```,`,,,,,`,,````-`-`,,`,,`,`,,`---

GRADUATED CYLINDER

b

Figure 7. Liquid Displacement Sampling



S T D * G P A S T D 2 L 4 0 - E N G L 1997

3 8 2 4 b 9 9 00118544 3 T L

m

5.2.4 Connect the sample cylinder to sampling source at valve A exactly as shown in Figure 7.

5.3.3 Open valve A at sample source and thoroughly blow out any accumulated material. Close valve A at sample source.

5.2.5 With valves B, C, and D closed, open sample source valve A to full open position. Observe sample pressure on gauge L. Crack valve B and fitting at valve C to purge line. Do not allow pressure L to drop below original sample pressure. Discontinue purging after a sufficient time and only when liquid product is present. If the product flashes without leaving a liquid residue at valve B and the fitting at valve C, the operator must use his judgement in determining when to discontinue purging. Close valve B and tighten fitting at valve C.

5.3.4 Connect the sample cylinder to sampling source at valve A exactly as shown in Figure 7. 5.3.5 With valves B, C, and D closed, open sample source valve A to full open position. Observe sample pressure on gauge L. Crack valve B and fitting at valve C to purge line. Do not allow pressure L to drop below original sample pressure. Discontinue purging after a sufficient time and only when liquid product is present. If the product flashes without leaving a liquid residue at valve B and the fitting at valve C,the operator must use his judgement in determining when to discontinue purging. Close valve B and tighten fitting at valve C.

5.2.6 With valve D still closed, slowly open valve C to full open position. Pressure at gauges L and M should be equal. 5.2.7 Slowly open valve D to allow a slow discharge of the glycol or water displacement liquid into the measuring vessel. To prevent flashing, do not allow pressure M to drop below sampling pressure. Continue operation until 80% by volume of the displacement liquid has been displaced by product in the sample cylinder.

5.3.6 With valve D still closed, slowly open valve C to full open position. Pressure at gauges L and M should be equal.

--````,,```,,,```,`,,,,,`,,````-`-`,,`,,`,`,,`---

5.3.7 Slowly open valve D to allow a slow discharge of the water into the measuring vessel. To prevent flashing, do not allow pressure M to drop below sampling pressure. Continue operation until 70% by volume of water has been displaced by product in the sample cylinder.

5.2.8 Close valves D, C and A in that order. Open valve B to release pressure on sample line.

5.3.8 Close valves D, C, and A in that order. Open valve B to release pressure on sample line.

5.2.9 With sample cylinder still attached to source valve A, slowly open valve D to drain the remaining 20% displacement liquid from the sample cylinder. After 1 5 ml has been withdrawn, the operator should reduce the drain rate and carefully extract the remaining water or glycol. (The displacement liquid may become cloudy just prior to the end point, although the effect is less noticeable with glycol.) At this time, reduce the rate to 10 ml/min maximum. When the first indication of product appears, usually a flashing bubble, close valve D immediately with no further loss of product. Disconnect cylinder from sample source.

5.3.9 With sample cylinder still attached to source valve A, slowly open valve D to drain another 20% of the water from the sample cylinder. (At this point, 10% of the water still remains in the sample cylinder.) Disconnect sample cylinder from sample source. 5.3.10 Check valves C and D for leaks, cap valves to protect threads, prepare sample information tag and box for transportation as per Department of Transportation or applicable requirements.

5.2.10 Check valves C and D for leaks, cap valves to protect threads, prepare sample information tag and box for Uansportation as per Deparunent of Transportation or applicable requirements.

6. LIQUID PHASE LABORATORY HANDLING AND PREPARATION

6.1 Recommended Procedures for Liquid Phase Samples Prior to injection of the Sample into the Test Device

5.3 Waier Displacement Method - Partial Displacement

6.1.1 Floating Piston Cylinders

5.3.1 A double valve sample cylinder filled with clean water and a vessel to measure the displaced liquid are required for this method (see Figure 7). The water used must meet the same requirements as in 5.2.1.

6.1.1.1 For floating piston cylinders refer to Figure 8 and proceed as follows: Connect a source of inert gas to valve A so that pressure may be applied to the sample via the floating piston. Apply a pressure not less than 200 psi (1 379 kPa) above the vapor pressure of the sample at the temperature of the sample injection valve by opening the valve on the inert gas source ard valve A. The inert gas pressure is to be maintained

5.3.2 The total volume of the sample cylinder must be found; then 70% and 20% of the total volume should be calculated. (For example, if the total volume of the cylinder is 500 ml, then 70% of the total volume is 350 ml and 20% is 100 mi.)



S T D n G P A S T D 2140-ENGL L997

3824b77 0018545 238

CAUTION: Extreme care must be used to ensure that no flashing of sample occurs in the inlet sampling line and valve system. Any measurements should be taken al sample purge valve C , never at sample valve B . The sample line and valve system should remain at 200 psi (1379 kPa) above the vapor pressure of the product.

on the sample container at all times during the analysis via a prcchargc regulator or similar device. 6.1.1.2 The sample should be thoroughly mixed per the cylinder manufacturer’s recommendations, whether it be by “mixing dasher”, “mixing ball” or equivalcnt, immediately prior to each analysis.

6.1.1.6 Operate the liquid sample valve either manually or automatically to inject the liquid sample into the carrier gas flow immediately ahead of the chromatographic column. The sample injection valve should be actuated quickly and smoothly to place the sample onto the column all at once and to ensure continuous carrier gas flow through the column.

6.1.1.3 Connect the sample end of the cylinder, valve B, to thc inlet of the chromatograph liquid sample valve. A l l connections and tubing are to be made of material impervious to the sample composition with the smallest diameter and shortest length of plumbing practical, thereby minimizing “dead space”. All tubing between the sample cylinder and liquid sample valve should be the same diameter.

6.1.1.7 When sample injection is complete, close valves B and A in that order, then close valve on inert gas source. Slowly open valve C and vent any remaining unused sample in the system through an appropriate vent.

6.1.1.4 With valve C closed, open valve B to fill the sample valve and associated lines.

6.1.1.8 Disconnect the cylinder from the inlet of the chromatograph liquid sample valve and the inert gas source.

6.1.1.5 Slowly crack valve C to purge the sample valve and associated lines. Be sure sufficient volume is displaced to purge unmixed areas in the sample cylinder as wcll as the sample injection system. When the purge is complete, close valve C.

6.1.1.9 If the sample is to be reused, do not take an outage

I

‘111.

CARRIER

CARRIER GAS

CHROMATOGRAPH

LIOUIDVALVE UMPLING

l

FLOATING PISTON l PRESSURE N G RNEEDLE q bVALVE [

1

1

r

CYLINDER NEEDLE VALVE

CYLINDER OUTLET VALVE

NEEDLE

VENT VALVE

o

GAS

RELIEF VALVE VALVE

INERT

GAS

1

1

NGL

RELIEF VALVE

Figure 8. Repressuring System and Chromatograph Valving with Floating Piston

47 --````,,```,,,```,`,,,,,`,,````-`-`,,`,,`,`,,`---



or reduce pressure on the piston cylinder. Check valves for leaks, cap valves to protect threads, and store the cylinder in a suitable location. 6.1.2 Double Valve Cylinders

6.1.2.1 For double valve displacement cylinders, refer to Figure 9 and proceed as follows: Connect the sample cylinder Y to cylinder X so pressurizing fiuid can enter into the bottom of cylinder Y. (The pressurizing fluid should be same type used to secure the product.) With this configuration the hydrocarbon sample will be taken from the upper portion of the cylinder. Open valve A and pressurize cylinder X w i t h inert gas. Maintain a pressure at least 200 psi (1379 kPa) above the vapor

pressure of the hydrocarbon sample at operating conditions. Open valves B and C to admit pressurizing fluid into sample cylinder Y. 6.1.2.2 Mix the sample thoroughly by gently inverting cylinder Y several times. Fix cylinder Y in a vertical position by means of a ringstand or similar device. Allow it to remain immobile in the vertical position at least 2 minutes before injection of sample into the chromatograph.

6.1.2.3 Connect the sample outlet valve D on cylinder Y to the inlet of the chromatograph liquid sample valve. A!l connections and tubing are to be made of material impervious to the sample composition, utilizing the smallest diameter and

VENT VALVE PRESSURE REGULATOR

r c CHROMATOGRAPH LIQUID SAMPLING

CARRIER GAS

CARRIER GAS

l

l

I

CYLINDER

->

CYLINDER

'Y

-- -- -- LAYER NGL -

--- -- --

. .......

.......

.. .. .. .. .. ....

..'GLYCOL' : ;., OR " . WATER

.-*GLYCOL' : : . OR .. WATER

$AS

.,o.

o

e

o.

.*

.:

. . . . ..

. . . .

Figure 9. Repressuring System and Chromatograph Valving with Double Valve Displacement Cylinder

48 --````,,```,,,```,`,,,,,`,,````-`-`,,`,,`,`,,`---



shortest length of plumbing practical, thereby minimizing “dead space”. All tubing between the sample cylinder and liquid sample valve should be the same diameter.

6.1.2.10 Check the valves for leaks, then cap valves io protect the threads and store the cylinder in a suitable location. 7. SAFETY PRECAUTIONS

6.1.2.4 With valve E closed, open valve D to fill the sample valve and associated lines. 6.1.2.5 Slowly crack valve E to purge the sample valve. When the purge is complete close valve E.

CAUTION: Extreme care must be used I O ensure that no flashing of sample occurs in the inlet sampling line and valve sysrem. Any measurements should be taken at sample purge valve E , never at sample valve D . The sample line and valve system should remain at 200 psi (1379 kPa) above the vapor pressure of the product. 6.1.2.6 Operate the liquid sample valve either manually or automatically to inject the liquid sample into the carrier gas flow immediately ahead of the chromatographic column. The liquid sample valve should bc actuated quickly and smoothly to place the sample onto lhe column ail at once and to ensure continuous carrier gas flow through the column. 6.1.2.7 When sample injection is complete, close vaives D and C on cylinder Y and valves B and A on cylindcr X, in that ordcr, then closc the valve on the inert gas source. Slowly open valve E and vent any remaining unused sample in the system through an appropriate vent, (If the sample is to be reused immediately, do not take an outage or reduce pressure on the sample cylinder. If the sample is not to bc reused immediately, procecd to next step, 6.1.2.8.) 6.1.2.8 Disconnect cylinder Y from the inlet of t h e chromatograph liquid sample valve and disconnect from cylinder X. Disconnect Cylinder X from the inert gas source.

6.1.2.9 With cylinder Y remaining in the upright position, remove 20% by volume of the pressurizing fluid for outage. This is accomplished by slowly opening valve C to allow a slow discharge of the pressurizing fluid into a measuring vessel.

7.1 Sampling hydrocarbon fluids can be hazardous. Persons responsible for obJning samples should be familiar wilh and adhere to safc practices for handling flammable fluids under pressure. 7.2 In all cases, a 20% (or more) inert gas charge should be present in all floating piston cylinders and a minimum of 20% displacement fluid outage in all double valve sample cylinders. 7.3 Disassembly of the Piston Cylinder

CAUTION; D i s a s s e m b l y of the p i s i o n cylinder f o r maintenance requires special precautions. If either end cap is removed while pressure is on the cylinder, the end caps and he piston can be ejected with such a force as I O cause serious injury to personnel and damage to adjacent equipmenl. 7.3.1 Clamp the piston cylinder firmly to a steady work surface. Caution should be taken not to dent or bend the cylinder by applying excessive pressure. 7.3.2 Using a suitable venting apparatus (e.g. vent hood), properly vent both ends of the cylinder before attempting to remove either end cap. 7.3.3 The work surface at either end of the cylinder should be clear before the end plug is loosened.

7.3.4 Provide a mechanical plunger to dislodge the piston from the cylinders, provided the plunger is of suitable material as to not scratch the cylinder bore. Do not use fluid Dressure to flislodnethe piston, KOTE 4: For reproducible sample volume limils see GPA publication 2177.

49 --````,,```,,,```,`,,,,,`,,````-`-`,,`,,`,`,,`---



PROPANE DRYNESS TEST (Cobalt Bromide Method) tube which in turn shall be partially surrounded by a metal shield. The glass tube shall be sealed at its inlet end to a pipe fitting and at the other end to a fine capillary orifice which serves as the outlet. See Fig. 2. The moisture indicators may be purchased ready for use or they may be prepared as follows: The cotton plugs shall be shaped and sized to fit in the glass tube loosely. Each plug shall be Fpyoximately ?' in. i long. After soaking in a szturated solution of cobaltous bromide the plugs shall be placed in a test tube or flask and dried. Drying is accomplished by heating to a temperature not to exceed 212 F while simultaneously evacuating the container. When properly dried the plugr; will be green or blue. They may be stored in sealed bottles or a desiccator, but the preferable method is to encase each plug in a separate gelatin capsule. (b) Pressure Gage. An accurate pressure gage of suitable range and scaIed in single pounds shall be provided. (c) Needle Valve. The needle valve required shall be capable of accurately controlling the flow of gas through the equipment with a minimum of adjustment. (d) Ice Bath. The ice bath shall consist of a container filled with water and cracked ice to a depth sufficient to immerse the cooling COU and all but the tip of the attached indicator. The temperature of the ice bath shall be maintained within a range of 32-34 F. (e) Cooling Coil. The cooling coil shall consist of at least 2 feet of % in. O.D. copper tubing coiled so that it may be conveniently immersed in the ice bath. The inlet of the coil. shall extend well above the bath and shall be fitted with a suitable connection to accommodate the pressure gage and needle valve. The outlet of the coil shall point upward so that when attached to the indicator it can be readily immersed up to within in. of the tip of the indicator. (i) Caps or Plugs. Adequate caps or plugs shall be provided for the inlet and outlet of the assembly to prevent moisture from entering the apparatus when the test is not being performed.

SCOPE 1. This test is intended to give an indication of the dryness of Commercial Propane and Propane HD 5.

APPARATUS 2. The apparatus shall consist of the following:

(a) The Indicator. The indicator is essentially a device for intimately contacting a gas or vapor with finely divided cobaltous bromide under conditions such that the color of the cobaltous bromide may be observed at all times. The indicator shall consist of a lightly folded plug of cotton impregnated with cobaltous bromide. Thio plug of cotton shall be held in a glass

r-----

R

? i $

SAMPLïNG

FIG. I-ASSEMBLED

3. All tests shall be conducted with the apparatus connected directly to the vapor space of the tank, tank car or tank truck containing the propane to be tested, except in cases where local conditions will not permit. In such cases a dry sample container having a minimum capacity of 20 gallons shall be used and a liquid sample of not less than 70 per cent nor more than 80 per cent of the volume of the sample container shall be obtained.

APPARATUS'

'The required protective cap (see parogroph 2(f)) like that shown on top of the Indicator wos not shown at the base of the needle volve for reasons of sketch clarity.

50 --````,,```,,,```,`,,,,,`,,````-`-`,,`,,`,`,,`---



S T D - G P A S T D 2LLiO-ENGL

1777

m

3824b77 0038547 9 8 3

Chah

16 Threads R r Inch

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lhu13 Threadr

Per Inch

on

'window Both Sides

7

Cotton Impregnated With Cobaltous Bromide

A

Glass Tube 1.0. 3/1{

0.0.*y64

v4* Natlonal Plpe Threads

SECTION 8 - 8

MATERIAL Make From 5/< Hex Brass Bat, Except Cap To Be Made From Dlameter Brass Bar.

s/14

SECTION A-A

Finlrh FIG. 2-DETAIL

OF INDICATOR



- Whlte

Nickel

____

S T D - G P A S T D 2L40-ENGL 1777

ASSEMBLY OF APPARATUS 4. la) The apparatus shall be assembled as shown in Fig. 2. The needle valve shall be attached to a vapor outlct of the propane container by means of suitable pipe or tubing connection of minimum length. (b) The ôssembled coil and indicator shall be adjusted to a vertical position. The ice bath shall then be placed in such a position that the coil and all but rpproximately 1,- in. of the tip of the indicator will be immcrsed. PRECAUTIONS

5. (a) All tubing and fittings must be absolutely dry and free of oil or foreign matter, CO that the indicator will not be contaminated or the results of the test obscured. (b) Keep the caps or plugs on the inlet and outlet of the asrembly at all times when the apparatus is not in use and remove the cap on the outlet orifice only when the actual testing is in progress. (c) The final color of the indicator will be the original blue, lavender or pink. Extreme care shall be exercised in distinguishing blue from lavender color as any change from the original blue color indicates a marginal moisture content..

=

=

from the outlet of the indicator. (b) The needle valve, Fig. 1, shall then be carefully opened until the pressure gage registers 50 -C 2 pounds per square inch and shall be edjusted i o maintain this pressure for the duration of the test. If the container pressure is less than 50 psig secure a sample as outlined in Sect. 3. (c) If the original blue color persists for 30 minutes of test exposure, the pressure shall then be reduced to 7 pounds t 2 pounds for five minutes. If the original blue color persists throughout this period, the material shall be reported as being “dry.” If the color changes to lavender or pink at reduced pressure, then the material shall be reported as being “wet.” (d) If the color changes to lavender or pink during the 30 minutes of test exposure at 50 f 2 pounds per square inch (it may occur in a few minutes), the material is either “wet” or the tubing and fittings contain water. To determine the cause of the color change. the pressure on the apparatus shall be adjusted to 5 pounds per square inch or less. (1) If the indicator turns blue it can be assumed that the tubing and fittings are free of water and the material shaii be reported as being “wet.” (2) If the indicator remains lavender or pink it can De assumed that the tubing and fitti I .s contain water. The apparatus and r.onnections shall be dried and the test repeated.

TEST PROCEDURE AND INTERPRETATION 6. ia) The valve on the source of propane vapor to be tested shall be opened and the cap removed


382Lib99 0018550 b T 5

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GPA 2140 - Liquefied Petroleum Gas Specifications and Test Methods

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