Research Research & Developm Developm ent Dept.
Test Test Procedur e for Testing o f Cryogenic Valves Valves Based o n B S 6364 6364,, API 598 598 and and EPA EPA m ethod etho d 21
RD-416 Rev. E
Test Procedu ro cedure re For Testin st ing g of o f Cryogenic Cryo genic Valv Valve es B ased o n B S 636 6364, 4, A PI 598 598 and EPA EPA Meth Method od 21
Revised Revised B y:
______________________ ____________________________ ______ Vahe Najarian, Eng. Corporate Manager, R&D and Engineering Support
Reviewed By:
______________________ ____________________________ ______ Christian Beguian, Eng. R&D Manager
DATE:
Feb 22, 2007
Rev i s ed B Y:
V. Najarian
REV.:
PAGE No :
E
1 of 9
Research & Developm ent Dept.
Test Procedur e for Testing o f Cryogenic Valves Based o n B S 6364, API 598 and EPA m ethod 21
RD-416 Rev. E
INTRODUCTION
1.
The following procedure covers the testing for sealing and operability of a) Cryogenic valves tested at -196 °C (-320 °F). b) Low temperature valves, tested at -46 °C (-50 °F). This procedure is based on BS 6364, API 598 and EPA Method 21, to the extent applicable and specified herein.
TEST PLAN
2.
The test comprised of the following tests at ambient temperature, then cryogenic or low temperature and again at ambient temperature as given below: 2.1
Ambient Temperature:
2.2
Cryogenic or low Temperature:
2.3
Ambient Temperature
DATE:
Feb 22, 2007
-
Shell and seat test according to API 598.
-
System proving seat test.
-
Repeat system proving seat test.
-
Operational tests for opening and closing torques.
-
Low pressure seat test.
-
High pressure seat test at incremental pressures up to high seat test pressure.
-
Repeat system proving seat test.
-
External leakage test.
-
Visual examination.
Revised BY:
V. Najarian
REV.:
PAGE No:
E
2 of 9
Research & Developm ent Dept.
Test Procedur e for Testing o f Cryogenic Valves Based o n B S 6364, API 598 and EPA m ethod 21
RD-416 Rev. E
3.
TEST TEMPERATURES
3.1
Ambient temperature:
Test performed at 25
3.2
Cryogenic temperature:
Test performed at -196
3.3
Low temperature:
Test performed at -46
4.
SEAT TEST PRESSURES
4.1
Low pressure seat test:
4.2
System proving seat test: Test at high seat test pressure (one increment), as per table below.
± 10
°C (77 ± 18 °F).
± 5
± 3
°C (-320 ± 9 °F).
°C (-50 ± 6 °F).
Test at 80 psig.
Exception: For soft seated ball valves at ambient temperature, Test at low seat test pressure (as per API 598). 4.3
High pressure seat test:
Pressure Class (ASME B16.34) 150 300 600 800 900 1500
*Note:
DATE:
Feb 22, 2007
Raise the pressure in increments up to seat test pressure as given in the table below. Measure and record the leakage rate at each pressure interval. High Seat Test Pressure* (psi) 275 720 1,440 1,800 2,000 2,000
Increment o f Test Pressure (psi) 100 250 375 375 400 400
If the valve maximum permissible working pressure at 20 °C or the valve seat rating is less than that shown in above table, use the lower value as the high seat test pressure.
Revised BY:
V. Najarian
REV.:
PAGE No:
E
3 of 9
Research & Developm ent Dept.
Test Procedur e for Testing o f Cryogenic Valves Based o n B S 6364, API 598 and EPA m ethod 21 4.4
Duration of Seat Test:
4.5
Direction of Seat Test:
RD-416 Rev. E
10 minutes minimum at each pressure interval.
4.5.1 Globe and gate valves:
Seat test is conducted in the normal flow direction for the valve.
4.5.2 Check valves:
Seat test is conducted in the reverse flow direction of the valve.
4.5.3 Ball and Butterfly valves:
Seat test is conducted in preferred direction.
4.5.4 Bidirectional sealing:
For valves, which are capable of sealing in both directions the normal flow (or preferred) direction only shall be tested. Upon specific customer request and agreement, each sealing direction can be tested separately.
5.
TEST SEQUENCE
5.1
Am bient Temperature Tests :
5.1.1 Perform shell and seat test according to API 598. 5.1.2 Purge the valve using helium gas. 5.1.3 Perform initial system proving test. Cryogenic or Low Temperature Tests:
5.2
5.2.1 Cool down the valve. When the valve has reached the required test temperature, allow for one hour of stabilization time, then testing may proceed. 5.2.2 Repeat initial system proving test. 5.2.3 Cycle the valve open-close 5 times. Record the operating torques for the first and last cycle. 5.2.4 Close the valve and pressurize the valve in the seat test direction to 80 psig. Wait at least 10 minutes to stabilize helium temperature.
DATE:
Feb 22, 2007
Revised BY:
V. Najarian
REV.:
PAGE No:
E
4 of 9
Research & Developm ent Dept.
Test Procedur e for Testing o f Cryogenic Valves Based o n B S 6364, API 598 and EPA m ethod 21
RD-416 Rev. E
5.2.5 Record seat leakage rate. 5.2.6 Increase the pressure in stages to the maximum seat pressure as described in Section 3.3. At each test pressure, wait at least 10 minutes to stabilize the gas temperature. 5.2.7 Record the seat leakage rate at each of the pressure intervals. Am bient Temperature Tests after Cryogenic Tests :
5.3
5.2.1 Remove the valve from liquid nitrogen and let it warm back to ambient temperature. 5.3.2 Repeat initial proving test. External L eakage Test
5.4
5.4.1 With the valve half-open, pressurize the valve to 90 psig helium gas. 5.4.2 Use the helium mass spectrometer to sniff the leakage around the valve for the entire test duration. Mass spectrometer is to be calibrated (before use) as per the equipment manufacturers procedure. A one-time packing-bolt, bonnet-bolt, and end-flange-bolt re-torque is allowed during testing. Valve Size 3” to 16” > 16”
Test Time (minutes) 6 9
5.4.3 Retainerless design dual plate check valves are exempt from external leakage test. A retainerless design has no openings through the body, i.e. no packing and no body/bonnet gasket. VISUAL EXAMINATION
5.5
After successful testing, the test flanges on the valve shall be removed and the disc and seat sealing area shall be visually inspected to the extent possible (practical only on large valves).
DATE:
Feb 22, 2007
Revised BY:
V. Najarian
REV.:
PAGE No:
E
5 of 9
Research & Developm ent Dept.
Test Procedur e for Testing o f Cryogenic Valves Based o n B S 6364, API 598 and EPA m ethod 21 6.
ALLOWABLE LEAKAGE RATES
6.1
Seat leakage: Valve Type Ball, gate, globe & Butterfly: Check:
RD-416 Rev. E
Allowed Seat Leak (standard cc/minute/inch) Class 150, 300 & 600 Class 800, 900 & 1500 150 200 300 400
6.2
External leakage:
at no time throughout the duration of the test, shall a reading of >1x10-4 cc/sec or 50 PPM be sustained for more than ten (10) seconds.
7.
TEST SET-UP for CRYOGENIC TESTS:
7.1
The valve to be tested is supported in a stainless steel tank. The sides and the underside of the tank are insulated on the outer faces. The valve is held between blind flanges with small bore piping leading to the fixtures to supply the pressurising media. Stem position is vertical for gate, globe, ball and butterfly valves. Check valves (swing, dual plate, etc.) may be tested in either vertical or horizontal disc position.
7.2
The valve temperature is lowered by filling the tank with the cooling medium (see below table), to a level above the body-bonnet bolting. The valve temperature is monitored by a thermocouple, installed on the valve body or end plate. The test is commenced when the valve temperature is stabilized within the test temperature tolerances, as indicated by the thermocouples. Cooling Medium Liquid Nitrogen. Dry ice, mixed with a heat transfer fluid (eg. Ethylene Glycol).
7.3
Test Valve @ Temperature Cryogenic @ -196 °C (-320 °F). Low temperature @ -46 °C (-50 °F).
Test gas (see below table) from a fully charged bottle is used to provide test pressure on the inlet side of the valve. The opening and closing torques for the valve are measured using a torque wrench. Test Gas Test Valve @ Temperature Minimum 97% pure Helium. Cryogenic @ -196 °C (-320 °F). Minimum 97% pure Helium or Nitrogen, mixed Low temperature @ -46 °C (-50 °F). with 1% Helium (for external leak detection).
DATE:
Feb 22, 2007
Revised BY:
V. Najarian
REV.:
PAGE No:
E
6 of 9
Research & Developm ent Dept.
Test Procedur e for Testing o f Cryogenic Valves Based o n B S 6364, API 598 and EPA m ethod 21
RD-416 Rev. E
7.4
All instruments (flowmeter, pressure gauges, torque wrench, etc.) are to be calibrated.
7.5
A typical test rig is shown on sketch ‘A’.
8.
Flowmeters, Flowmeter Calibration, Seat Leak, and Correcti on Factors:
8.1
Flow meter type: Any type may be used, provided that it can be calibrated.
8.2
Flow meter calibration: Are to be calibrated for the test gas (Helium or Nitrogen). Or, the manufactures correction factor is to be used to relate the calibration gas (typicall y Nitrogen) to the test gas.
8.3
Seat leak: Allowed seat leak is measured at the flowmeter, and are at standard atmospheric conditions.
8.4
Temperature Correction: Temperature of exiting test gas is to be measured (before flow meter). “Charle’s law” is to be used for temperature correction. I.e. V1*T2=V2*T1. Therefore, Q1*T2=Q2*T1. Where: V1 is test gas volume exiting the flowmeter. V2 is test gas volume expressed (corrected) at ambient temperature. T1 is test gas temperature exiting the flowmeter ( °R). T2 is the standard ambient temperature (528 °R). Q1 is test gas flow exiting the flowmeter (cc/min). Q2 is test gas flow exiting the flowmeter and expressed (corrected) at ambient temperature (standard cc/min).
8.5
Pressure Correction: Pressure of the exiting test gas is near atmospheric, and assumed to have negligible effect. Therefore, measurement of exiting pressure, as well as correction is not required.
8.6
Exemption: Some flow meters (eg. Electronic mass flow meters) are not affected by pressure or temperature changes, and can be calibrated to provide a direct reading at standard conditions. When such a flow meter is used, test gas pressure and temperature (as well as correction) at the flow meter is not required.
DATE:
Feb 22, 2007
Revised BY:
V. Najarian
REV.:
PAGE No:
E
7 of 9
Research & Developm ent Dept.
Test Procedur e for Testing o f Cryogenic Valves Based o n B S 6364, API 598 and EPA m ethod 21
DATE:
Feb 22, 2007
Revised BY:
V. Najarian
REV.:
RD-416 Rev. E
PAGE No:
E
8 of 9
Research & Development Dept.
Test Report fo r Testing o f Cryogenic Valves Based o n B S 6364, API 598 and EPA m ethod 21 Velan Order/Item/Position:
Test Date & No.:
Customer Order No.:
Project Name: Valve Fig. No.: Valve Type/Size/Class: Actuator Type & HW
RD-416 Rev. E
(in)
∅:
Flowmeter Type:
Valve Tag No.: Test Temperature Cooling Medium Test Gas: Allowed Seat Leak: Allowed External leak:
≥ 97% ≤
Pure scc/min
≤1x10-4 cc/sec or 50 ppm 3 Note: scc/min = standard cm /minute
AMB IENT TEMPERA TURE – INITIA L PROVING TEST:
Test Pressure (psig)
Duration of Seat Test (min)
Seat Leak Rate (scc/min)
CRYOGENIC or Lo w Temp TEST:
Valve stabilization Temperature (°F):
Initial Proving Test Pressure (psig)
Duration (min) Cycle
Valve stroked 5 times Record Operating Torques
Time: Seat Leak (cc/min)
Opening Torque (ft.lbs)
Closing Torque (ft.lbs)
st
1 5th
Low Pressure Seat Test (psig)
Duration (min)
Seat Leak (cc/min)
Incremental Seat Test:
Increment 1st 2nd 3rd 4th 5th
Pressure (psig)
Duration (min) Measured Seat Leak (cc/min) Corrected Seat Leak (scc/min)
Am bi ent Temp erat ur e Tests Initial Proving Test Pressure (psig)
Duration (min)
External Leakage Test Pressure (psig)
Seat Leak (scc/min)
Duration (min) Bonnet Joint
Valve Body Stem Seal
Visual Examination or Comments:
PASS ( ) FAIL ( X )
Tested By
DATE:
Feb 22, 2007
Approved By
Revised BY:
V. Najarian
Customer Witness
REV.:
PAGE No:
E
9 of 9
