Hydrostatic and Settlement Tests Procedure

Hydrostatic And Settlement Tests Procedure

C LIENT : ILAM Petrochemical Company

Prj. Doc. NO. : 10-VD-PCJ-QC-351144

MFS DOC.NO: MFS –PR-HT(IL)-86-06-441 (02)

ILAM ETHYLENE PLANT-ILAM OLEFIN COMPLEX 02

1.Mar.09

For Approval

R.N

01

28.Dec.08

For Approval

R.N

Rev.

Date

Description

Prepare.

Tech. Dep. Tech. Dep.

C hk.

A.S A.S

Ap p.

OLEFIN PLANT Ilam Petrochemical Complex

National Petrochemical Co.

Masnouat Felezi Sangin Doc.

Hydrostatic And Settlement Test Procedure

No. : 10-VD-PCJ-QC-351144

Rev. No. : 02 Sheet no. :

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CONTENT

1.0

Scope

3

2.0

Applicable Codes and Standards

3

3.0

Test Stages

3

4.0

Sequence of Work

4

5.0

Water

5

6.0

Method

5

7.0

Assessment and Report

10

8.0

Cleaning

10

Level Reference Table

11

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This procedure briefly describes the general methods to be performed for Hydrostatic and Settlement testing after completing welding operation and performing required N.D.T. Test for Storage Tanks. Before hydrostatic test, reports of all inspection and test as per relevant QCP such as joint history N.D.T map, punch list, test certificate, general drawing etc. approval by the owners representative shall be provided.

1.0. Scope The purpose of performing following test is to controlling and measuring any changes to body and foundation level and also to prove integrity of Storage Tanks body. This document applies to Nine Storage Tanks of OLEFIN PLANT ILAM PETROCHEMICAL COMPLEX. After completing erection and performing required Tests, Visual Inspection, Vacuum Box Testing, Pneumatic Test, Hydrostatic operation and settlement test will be performed. Accoding Applicable codes and standards as defined in item 20.

2.0. Applicable codes and standards 

API 650 Welded Steel Storage Tanks.



API 653 Tank Inspection, Repair, Alternation and Reconstruction.(Appendix B.)



Client Documents and specification No: 10-00-spc-ME-1003 Rev.c

3.0. Test Stages This test will divide to following mentioned stages: 

Test preliminaries such as visual inspection.



Inspection of Tank Bottom Welds (Vacuum Box Testing)



Inspection of Reinforcement-Plate Welds (Pneumatic Testing)



Testing of the Shell (Hydrostatic Testing)

It must be mentioned all of the mentioned test must perform after controlling all of the N.D.T. test reports.






4.0. Sequence of Work

N.D.T Test records

Settlement Monitoring Leak test

Water Filling Holding Stage Holding Stage Holding Stage Hydrostatic Test

Water Discharge

Holding Stage at 1/2 Ht

Settlement Monitoring

Holding Stage

Emptying Stage

Cleaning and Drying


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5.0. Water 

For accomplishment of hydrostatic test, storage tanks must filled with plant water and prior to filling the Storage Tank with water.

TEST METHODS IN ACCORDANCE WITH API 650 6.0. Method Describing inspection and test methods for following fixed & floating roof storage tanks, which were fabricated and tested in accordance with API 650: 

C5+Feed Tank (TK-031) Floating Roof



Pyrolysis Gasoline Tank (TK-903 A/B) Floating Roof



Benzene Stripper Feed Tank (TK-985)



Chemical Waste Neutralisation Tank (TK-984)



Caustic Tank (TK-981)



Spent Caustic Holding Tank (TK-941)



Fuel Oil Storage Tank (TK-904)



Sulphuric Acid Storage Tank (TK-982)

6.1. Test Preliminary 6.1.1. Visual Examination

All of the weld seams of bottom plates must be visually inspected. This inspecting shall meet the following requirements: 6.1.1.1. The surface of weld lines must free from cavities and construction derbries using trains of pigs fitted with brushes. 6.1.1.2. There must not be any pronounced lumps or cavities, which have been caused by starting or finishing a weld bead. 6.1.1.3. Welds must free from under cutting. The height and spacing or ripples must be uniform. For welds that attach nozzles, manholes and cleanout openings. 6.1.1.4. The profile of fillet welds must be uniform and surface of the weld must slightly convex and free from over lap at the toes of weld lines.






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If any problems meet in visual inspection, following corrective action must be performed before starting next stage of the test: 

Removing all of the defects by using mechanical means or thermal gouging processes.



Repairing arc strikes which have been discovered in or adjacent to weld lines by grinding and re-welding as required.



The repaired weld shall be visually examined for defects.

6.2. Inspection of Tank Bottom Welds by performing Vacuum Box Test:

After termination of visual inspection and cleaning above-mentioned surfaces, or performing corrective action, vacuum box testing will be executed by using following methods: 6.2.1. Vacuum testing is conveniently performed by using a testing Box with about15 cm wide and 75 cm long with a glass window in the top and sealing the open bottom with using a sponge-rubber gasket and suitable connections. Suitable connection valves and gauges shall be provided on it. 6.2.2. Approximately 75 cm of the seam under test, must brushed with a soap solution or linseed oil. In freezing weather, a non-freezing solution may be necessary. The vacuum box will place over the coated section of the seam, and vacuum will apply to the box. Bubbles will indicate the presence of porosity in the seams or foam, which was produced by air sucked through the welded seam. 6.2.3. A vacuum can be drawn on the box by any convenient method, such as connection to a gasoline- or diesel motor intake manifold or to an air ejector or special vacuum pump. 6.2.4. As an alternate to vacuum box testing, a suitable tracer gas and compatible detector can be used to test the integrity of welded bottom joints for their entire length provided that an appropriate tracer gas testing procedure has been reviewed an approved by the purchaser. \\Server\Users New\monshi\Monshi\SAYER MON 1 Projects\Olefin Petroshimi Ilam\procedure\ITP-02.doc





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6.3. Inspection of Reinforcement-Plate Weld

After completing fabrication and prior to filling the tanks with water for performance of hydrostatic test, all of the reinforcements shall be tested by pneumatic method. Applying up to 100 Kpa Pressure between the tanks shell and openings reinforce pads, with using contrived telltale holes on pads, and covering all of the attachments and welding around the reinforce pads by suitable material such as a soap film or linseed oil. If weld joints contained any defect, bubbles will appeared on the covered material. Suitable convenient method shall be applied for repairing all of the existent defects. 6.4. Testing of the Shell by using Hydrostatic Test Method

After the entire tank is completed but before any permanent external piping is connected to the tank, the shell shall be tested by Hydrostatic Testing. This Test must be performed after completing tank fabrication and finishing all of the welding operation and Radiographic Test, prior to painting and / or insulation. Hydrostatic testing methods consist of filling a Tank System with (Water) containing a max of 25 ppm chloride up to high liquid level or over flow nozzle, until a certain pressure is reached, and observing. A loss of liquid pressure can be attributed to a leak, a decrease in liquid temperature, distortion due to the pressure, or trapped vapor. During test operation, inspector should check for conformity with design drawings and specification, accessibility of valves, controls and gages and proper installation of water pumps. All equipment should be checked for correct identification and operating instructions. Water supply pipe work should be flushed thoroughly at the maximum practicable rate of flow, before connection is made to system piping, in order to remove foreign materials which may have interred during installation or which may have accumulated in the mains system at lower rates of flow. The minimum rate of flow for flushing should be not less than the water demand rate of the system. Filling operation and method will be according to clause 6.4.3 of this procedure.






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6.4.1. Hydrostatic Test provision 6.4.1.1. Interior of the tanks shall be free from greases, weld spatter, scale, slag, rust and any other foreign matter and broom swept. 6.4.1.2. Roof manhole (as vent) shall be open during of filling and emptying operation (very important). 6.4.1.3. All appurtenances inside of the tanks such as coils or pipe supports shall have been installed. 6.4.1.4. Settlement monitoring devices shall be provided prior to filling water. 6.4.1.5. Permanent or temporary tank level gauges shall be provided to monitor the water level. 6.4.1.6. Cleaning Surfaces (Internal / External) completely and pips and fittings should be carefully cleaned before assembly and any loose jointing material should be removed. 6.4.1.7. Installing of valves and fittings. 6.4.1.8. Installing pressure gauges. 6.4.1.9. Temporary water piping and pumps for filling and discharging shall be installed from the tank to water supply point and disposal point. 6.4.1.10. Hydrostatic test shall be commenced and finished during day lights hours. 6.4.1.11. Hydrostatic test chart(time &levels)shall be provided.

6.4.2. Type of settlement :

Type of settlement will be according to API653 Appendix B, clause B2 and should be recorded upon related formats.

6.4.3. Settlement Monitoring:

To restrain and monitoring foundation settlement, according to following mentioned method, filling will be done under controlled condition, which was measured with






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concerning speculation upon soil settlement and soil bearing capacity which have been concluded from ground research. Considering and marking 12 points (0º, 30º, 60º, 90º, 120º, 150º, 180º, 210º, 240º, 270º, 300º, 330º) around storage tank base ring as leveling references and measuring the elevation with 1mm accuracy with dial gauge. Before filling tanks with water the level at each mentioned reference point will be registered. Permanent reference level will be established in unaffected location of tanks (Bench Mark). Gauge contact surfaces should be provided with glued glass plates or similar for a smooth contact. 6.4.4. Filling 6.4.4.1. Filling operation

The test water shall be filled slowly until the water level reaches minimum 300 mm height. The water-filling rate shall not exceed 900 mm depth per hour, and then inlet nozzle shall be gradually opened and continuing filling operation. Water will be filled in to the tanks by approximately filling rate about

900mm /hr, until water level reach

to1/3Ht, at such a head, filling will stop for 6 hours and level at the reference points will be recorded. Continuing filling operation with 900mm/hr water flow rate up to water level reached to 2/3Ht of required hydro test level at such a head, filling will stop for 12 hours and levels will be measured and checked and comparing with registered measure before start of filling (while tanks were empty) to ensure that uneven settlement have not occur. In this situation, filling will proceed by the same rate up to water leveled reached to required height. Each day levels at reference points will register and recorded. (Refer to page 12 for filling diagram). 

The filled tanks will be maintained for 24 hours and provided levels remain consistent, the tank can be off loaded prior to calibration for service.

As filling of tanks, according to the mentioned method, will be done gradually and in steps, it prevents non-uniform settlement. During hydro test and after finishing of each one of filling steps or emptying stages, checking will be made on followings: \\Server\Users New\monshi\Monshi\SAYER MON 1 Projects\Olefin Petroshimi Ilam\procedure\ITP-02.doc





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

Settlement Monitoring



All shell welding joints lower than liquid level



Corner joints including the fillet weld between shell and bottom, which shall visually check for water tightness.



Shell roundness

Note: For repair of any leakage ad weld, water level shall be drained 330 mm below the failure point and after repair, hydrostatic test shall re-started from actual level. It must be mentioned prior to the roof installation, fixed roof column supports shall be inspected for plumbness and tank shells shall be inspected for distortion or ovalization. Roof support columns which are out-of-plumb by more than 15mm in every 3m and/or more than 60mm for the total length shall be realigned. 7.0. Assessment and Report

Gauge measurements and visual inspection shall be assessed and reported together with measurement records, including gauge plots relative to water levels. The measurement records shall be issued to the engineering manager and company and the engineering manager shall review and interpret measurement records if anomalies are happened, the engineering manager shall instruct the site immediately to stop the water filling, and shall discuss with Company. 8.0. Cleaning

The tanks shall be completely drained and thoroughly dried immediately after hydrostatic Test. If necessary during discharging the test water, put the inflatable boat on the test water and brushing the wall by using the boat as water level goes down. After the tanks were emptied, surfaces of the bottom plates shall be cleaned with fresh water. Water, which will be used for cleaning, shall be same quality as test water. All sand, sludge and rubbish shall be removed from the tanks bottom. After final draining and drying, brushing, broom or vacuum cleaner shall clean surface of the tanks bottoms.






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Level Refrence Table

Reference Point

Height of Level Indicator

Date

0º 30º 60º 90º 120º 150º 180º 210º 240º 270º 300º 330º


Time

Hydrostatic and Settlement Tests Procedure

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