1.hydrostatic test and flushing(r2)

8/2/2019 1.Hydrostatic Test and Flushing(R2)

1/19

YANBU II POWER & WATER PROJECT

PACKAGE: 3

Hydrostatic Test and FlushingProcedure for Piping

Document No. :Revision :Date of Issue :


2/19

YANBU II POWER &WATER PROJECT

Contract PO No.: Hydrostatic Test andFlushing

Procedure for Piping

Date of Issue:

Doc No. : Page 2 of 19

Rev No. :

METHOD STATEMENT FOR SPOOL FABRICATION OF STEEL PIPING

Document No. :

Project Name : YANBU II POWER & WATER PROJECT

Contract No. :

Client :

EPIC CONTRACTOR

Rev Date Description Prepared by Reviewed by Approved by


3/19


Contract PO No.: Hydrostatic Test and FlushingProcedure for Piping

Date of Issue:


Rev No. :

Plant : Document No. : Rev.

Title :

Hydrostatic Test and Flushing

Procedure for Piping

REV. DATE DESCRIPTION BY CHK APP

Project :

Project Co. :


4/19



Date of Issue:


Rev No. :

EPC Contractor :

CONTENTS

SECTION PAGE1.0 SCOPE3

2.0 REFERENCES3

3.0 EXCLUSIONS3

4.0 INSPECTION ....4

5.0 PRESSTRE TEST..4

5.1 General4

5.2 Extent of Testing.4

5.3 Test Preparation..5

5.4 Test Fluid and Test Pressure..6

5.5 Test Procedure.. 7

5.6 Completion of Testing.. 7

5.7 Test Records. 8

6.0 FLUSHING.... 9

Appendix 1 Cleanliness Requirements for Internal of Piping 12

Attachment #1 Piping Line Final Certificate & Pressure Test Certificate (Fuel Gas Line)... 15

Attachment #2 Legend for Pressure Test ... 16

Attachment #3 Standard Detail for Pressure Test... 17


5/19



Date of Issue:


Rev No. :

1.0 SCOPE

This procedure covers the general requirements for flushing and pressure testing of piping systems to be

used for YANBU II POWER & WATER PROJECT. This procedure shall be used in conjunction with

the pressure test flow diagrams line list contained test blind locations, test legends, test pressure, test

fluids, and other pertinent information.

2.0 References

2.1 Relevant Documents

Unless otherwise specified, all reference documents, code and practices shall be taken in their latest

edition

- Design Criteria for Piping

- Piping Material Specification

- Piping Construction Specification

- ASME B31.1 Power Piping

3.0 EXCLUSIONS

The following piping accessories and equipments shall be excluded or isolated from pressure testing of

piping, but not limited to ;

1) Rotating machinery, pumps, compressors, etc.

2) Filter elements of strainers.

3) Pressure relieving devices such as rupture discs and pressure relief valves.

4) Pressure Vessels and Heat Exchangers.

5) All instruments, including level controllers and gauge glasses.

6) Pressure gauges.

7) Expansion joints.

8) Orifice plates.

9) Flow nozzles.

10) Pressure control valves.

11) Deluge nozzles.

12) Any other piping or equipments designated by Company (packaged units /

Equipments shall be isolated or by-passed as required)

4.0 INSPECTION

After completion of fabrication and erection, and prior to hydrostatic/pneumatic testing, the

piping system shall be inspected to ensure that:


6/19



Date of Issue:


Rev No. :

Proper piping material has been used.

Piping has been erected as per drawings

All supports have been installed properly

5.0 PRESSURE TEST

5.1 General

The test pressure shall, unless otherwise specified, be in accordance with ASME B3 1.1 Section 137 or this procedure.

5.2 Extent of Testing

With the exclusion of instrumentation, piping systems assembled in the field shall be pressure tested.

1) To facilitate the testing of piping systems, vessels and other equipments shall be included in the system if the

test pressure specified is equal to or less than that for the vessels and other equipments.

2) Pumps, compressors and other rotating equipment shall not be subjected to field pressure test.

3) Lines which are directly open to atmosphere such as vents, drains, safety valves discharge should not be

tested, but all joints shall be visually inspected

4) However, such lines if provided with block valve shall be pressure tested up to the first block valve.

5) Seats of all valves shall not be subjected to a pressure in excess of the maximum cold working pressure of the

valve. Test pressure applied to valves shall not be greater than the manufacturers recommendation nor less

than that required by the applicable code. Where allowable seat pressure is less than test pressure, test shall

be made through an open valve.

6) Instruments in the system to be tested shall be excluded from the test by isolation or removals.

7) Restrictions which interfere with filling, venting and draining such as orifice plates etc. shall not be installed

unless testing is completed.

8) Control valves shall not be included in the test system. Where bypasses are provided, test shall be performed

through the bypass.

9) Pressure gauges which are parts of the finished system, but cannot withstand test pressure, shall not be

installed until the system has been tested. Where piping systems to be tested are directly connected at the

battery limits to piping for which the responsibili ty rests with other agencies, the piping to be tested shall be

isolated from such piping by physical disconnection such as valve or blinds.

5.3 Preparation for testing

1) Prior to commencing Testing, QM shall verify with the Company's representative that all required non-

destructive testing (NDT) such as radiography, ultrasonic, post-weld heat-treating, etc., has been completed.

2) Piping to be tested shall be barricaded as precautionary measure in the event of piping system rupture to

eliminate hazards to personnel in the proximity of lines being tested.

3) Test shall be carried out with permanent gaskets installed unless specified otherwise.

4) All piping systems to be hydrostatically tested shall be vented at the high points and the systems purged of air

before the test pressure is applied.

5) All piping field joints and welds shall be left UN insulated, exposed and primer coated for examinationduring the test.

6) Pressure gauges used in testing shall be installed as close as possible to the lowest point in the piping system


7/19



Date of Issue:


Rev No. :

to be tested, to avoid overstressing of any of the lower portions of the system. For longer lines and vertical

lines, two or more pressure gauges shall be installed at locations decided by the Engineer-in-Charge.

7) For lines containing check valves, any of the following alternatives shall be adopted for pressure testing.

8) Where possible, pressurize up-stream side of valve. If this impractical, the check valve shall be reversed or

provide blind on valve flanges and test the upstream and downstream of the line separately and remove the

blind after testing. At these flanges, temporary gaskets shall be provided during testing and shall be replaced

by permanent gaskets subsequently.

9) Piping which is spring or counter-weight supported shall be temporarily supported, where the weight of the

fluid would overload the support. Retaining pins for spring supports shall be removed only after testing is

completed and test fluid is completely drained.

10) When testing any piping system, air of approximately 2 bars may be used as preliminary test to detect missing

gaskets etc. as this avoids the necessity of draining the line to make repairs.

11) All piping shall be adequately supported before the pressure test. Spring or other variable type Supports shall

be locked to prevent movement.

12) Piping containing check valves shall have the source of test pressure on the upstream side or removed

clappers.

13) All in line valves including ball valves shall be pressure tested in the half open position. Other valves shall

be tested in the fully open position. But, all control valves shall be removed prior to testing. Care must be taken

not to damage valve soft seats.

14) Piping and equipment may be insulated before testing, but all circumferential welding joints shall be left UN

insulated until suitable test acceptance by Company.15) Hydro testing shall be performed via a manifold. The test pump shall be isolatable from the system with its

own pressure gauge. Valves, hoses used in tests shall be suitable rated (use rating of max. test on line list

throughout to avoid any confusion)

5.4 Test Fluid and Test Pressure

5.4.1. Test Fluid

1) In general all pressure tests shall be hydrostatic using plant water or raw water which is clean and free of silt.

Maximum chlorine content in water for hydrostatic testing for stainless piping shall be 50ppm.

2) Air shall be used for testing if water would cause corrosion of the system or overloading of supports etc.

Instrument air, service air, cooling air, Co2/N2/H2, fuel gas/oil, LP steam and GT bleed air piping shall be

pneumatically tested.

3) For pneumatic testing, the test media shall be nonflammable or nontoxic. The use of air for testing shall be

limited to a maximum pressure of 8.0 bars and in case only nitrogen gas for testing shall be limited to a

maximum pressure of 100 bars.

5.4.2. Test Pressure

The hydrostatic/pneumatic test pressure shall be as indicated in the line list or test package.

5.4.3. Hydrostatic Test Pressure

1) The hydrostatic test pressure at any point in the piping system shall not be less than

1.5 times the design pressure, but shall not exceed the maximum allowable test pressure of anyno isolated components such as vessel, pumps, or valves, nor shall it exceed the limits imposed

by Para. 102.3.3(B) of B31.1.


8/19



Date of Issue:


Rev No. :

2) The pressure shall be continuously maintained for a minimum time of 10 minutes

and may then be reduced to the design pressure and held for such time as may be necessary to

conduct the examination for leakage.

5.4.4. Pneumatic test pressure

1) The pneumatic test pressure shall not be less than 1.2 or more than 1.5 times the design pressure of the piping

system. The test pressure shall not exceed the maximum allowable test pressure of any non-isolated

components such as vessels, pumps, or valves, in the system.

2) For firefighting system, the piping shall be pneumatically tested in closed circuit for a period of 10 min. at 40

psi (276 kpa). At the end of 10 min. the pressure drop shall not exceed 20% of the test pressure (Para

7.7.2.2.12 of NFPA 2001- 2008 edition)

3) The pressure in the system shall gradually be increased to not more than one-half of the test pressure, after

which the pressure shall be increased in steps of approximately one-tenth of the test pressure until the required

test pressure has been reached.

4) The pressure shall be continuously maintained for a minimum time of 10 minutes and shall then be reduced to

the design pressure and held for such time as may be necessary to conduct the examination for the leakage.

5.4.5. Test pressure Gauge

1) All gauges used for field testing shall have suitable range so that the test pressure of the various systems falls

in 35% to 65% of gauge scale range. Gauge shall have accuracy of at least 1 % of full scale.

2) Prior to the start of any test or periodically during the field test program, all test gauges shall be calibrated

using a standard dead weight gauge tester or other suitable testing apparatus and test certificate shall beavailable.

3) A minimum two pressure gauges are required for the test system. One pressure gauge shall be on the test

pump and the other on the test system.

5.5 Test Procedure

5.5.1. Hydrostatic Test

1) All vents and other connections used as vents shall be left open while filling the line with test fluid for

complete removal of air. In all lines for pressurizing and depressurizing the system, temporary isolating valves

shall be provided if valve, vents, drains do not exist in the system.

2) Pressure shall be applied by means of a suitable test pump or other pressure source which shall be isolated

from the system as soon as test pressure is reached and stabilized in the system.

3) The pump shall be attended constantly during the test by an authorized person. The pump shall be isolated

from the system whenever the pump is to be left unattended.

4) Test pressure shall be maintained for a sufficient length of time to permit thorough inspection of all joints for

leakage or signs of failure. Any joint found leaking during a pressure test shall be retested to the specified

pressure after repair. The pressure shall be continuously maintained for a minimum time of 10 minutes.

5) The pump and the piping system to be tested are to be provided with separate pressure indicating test gauges.

These gauges are to be checked by the standard test gauge before each pressure test.

6) Care shall be taken to avoid increase in the pressure due to temperature variation during the test, if pressure

rise, some quantities should be drained to maintain the pressure level. .

7) Gradual increase in pressure required for GRP/GRE piping as per vendor recommendations. Sudden pressure

surges or water hammer should be avoided. Test pressure will be 1.5 x Design pressure as shown in line list.


9/19



Date of Issue:


Rev No. :

The test pressure will be held for minimum 10 minute.

8) For pressure tests greater than 2,900 psi (200 bar = 204 kg/cm2 ), the pressure build up shall be as follows

25%, 75% test pressure in stage allowing a period of 5 minutes at each stage in order to permit system to

stabilize.

5.5.2 Pneumatic Test

1) When testing with air, pressure shall be supplied by means of a compressor with a

receiver, after cooler and oil separator.

2) Piping to be tested by air shall have joints covered with a soap and water solution so that

the joints can be examined for leaks.

3) All other details shall be same as per hydro testing procedure (specified above).

5.6 Completion of Testing

1) After the hydrostatic test has been completed, pressure shall be released in the highest vent point in a manner

and at a rate so as not to endanger personnel or damage equipment.

2) All vents and drains shall be opened before the system is to be drained and shall remain open till all draining

is complete, so as to prevent formation of vacuum in the system. After draining, lines/systems shall be dried

by air.

3) After testing is completed, the test blinds shall be removed and equipment/piping isolated during testing shallbe connected using the specified gaskets, bolts and nuts.

4) Items that were removed from test shall be reinstalled.

5) Pressure test shall be considered complete after approved by the Owner. Defects, if any, noticed during

testing, shall be rectified immediately.

5.7 Test Records

Test records shall be prepared and submitted by the inspector for each piping system for the

pressure test done in a defined format.

6.0 FLUSHING


10/19



Date of Issue:


Rev No. :

6.1 The flushing shall be carried out after pressure testing. But in case water flushing shall be carried

out after pressure testing. Pipe work shall be free from dirt, grease or temporary protective

coatings, e.g. tape, at all joints including welded attachments.

6.2 The flushing shall be proceeded to expedite the progress even though the document review (like NDE review) was

not done. Any outstanding repairs will require re flushing, unless specifically approved otherwise.

6.3 All flushing activities must be witnessed by Companies Representative and Contractor QC inspector.

The Cleanliness of flushed pipe work must be to the satisfaction of Companies Representative.

6.4 Preparation and Procedure

1) Generally the flushing medium shall be plant water, raw water, steam or compressed air and

seawater for GRP/GRE lines. In cases where water flushing is not desirable in the piping system (e.g.

instrument air etc.), flushing by compressed air shall be carried out.

2) For air flushing, the pipe line/system will be pressurized by compressed air to the maximum

pressure of 50 psig or up to design pressure whichever is lower. The pressure shall then be released by

quick opening of a valve, already in line or installed temporarily for this purpose. This procedure shall be

repeated as required till the inside of the pipe is cleaned to the cleanliness levels of particular piping

system as indicated in Appendix 1 of this document. Caution: small bore pipe work which is safety

hazard shall require personnel barriers.

3) The cleaning fluid shall not flow through vessels, pumps and other rotating equipment whichare already cleaned and preserved by respective vendor. The pipe line shall be disconnected and blanked

off before flushing/blowing.

4) Pumps and other rotating equipment designed with tight clearances as well as some control

valves and in-line instruments like orifice plates, Rota meters, and safety valves etc. which may interfere

or be damaged by flushing (water, steam or compressed air) shall be removed, blocked off or isolated.

5) All in line valves such as Butterfly valve, Gate valve, Ball valve (equal or less than 4),

Globe valve and DBB valves shall be flushed in fully open position. But, other valves such as Control

valves, Flange type Check valves shall be removed or bypassed.

6) All instrument impulse pipe work shall be disconnected prior to flushing and shall remain

disconnected during pressure test.

7) All check valves larger than 2.5 shall be removed for duration of flushing.8) The screens/meshes shall be removed from all strainers before flushing. Screens/meshes

shall be reinstalled after flushing but before testing.

9) The contractor shall carry out all the activities required before, during and after the flushing

operation as per flushing requirements, such as removal of valves, special items, distance pieces, inline

instruments and any other piping part before flushing. The flanges shall be disengaged andprovided with

temporary gaskets at the time of flushing. Refer to P&IDs and piping isometric drawings.

10) After flushing is completed, the valve, distance pieces, piping specials etc. shall be

reinstalled by the contractor with permanent gaskets. However, flanges at equipment nozzles and other

places where isolation is required during testing, only temporary gaskets shall be provided. A proper

record by marking on the P&IDs and the isometric drawings shall be maintained.

11) The cleanliness shall be verified visually or if required by other appropriate method

specified

12) In case the piping system cannot be taken into commissioning directly after Pressure Testing


11/19



Date of Issue:


Rev No. :

such as feed water, main stream and fuel gas piping. The piping shall be dried prior to introducing

nitrogen and preserved with nitrogen.

13) All opening in cleaned system shall be sealed with cap, plug or blind plate.

14) The system shall be pressurized with nitrogen up to 0.3 kg./cm2 and maintained with the

pressure between 0.2 kg/cm2 and 0.3 kg/cm2 by adding nitrogen.

15) Records shall be prepared by the inspector of the Contractor and submitted to the Owners

representative to sign acceptance of cleanliness, if the Owners representatives want to review it.

6.5 Steam Blowing

Follow the document of Steam Blowing out Procedure: will be informed later.

6.6 Air Blowing

1) This method should be used as a cleaning method for fuel gas, fuel oil, instrument/service air and N2/Co2/H2

gas lines and feed water line. Two main methods of air blowing shall be used depending on the diameter of

the lines, the quantity of fluid to be used and the time needed to fill in the system at the desired pressure.

2) Practically, continuous air blowing may be used up to NPS 6 pipe, the quick decompression method for

pipes over NPS 6.

3) Air is continuously blown from a source (Air compressor of a large capacity) at a high velocity through the

lines to carry away the foreign matters. Due to high velocity of the air, a light erosion of the walls generally

can occur during the air blowing, which is beneficial with regards to cleaning. Blowing of galvanized steel

pipe shall be mild so as not to affect the galvanized coating.

4) Quick decompression

5) A pipe network is pressurized by compressed air up to a maximum pressure of 50 psig or up to design

pressure whichever is lower. The pressure shall then be released by quick opening of valve, already in line or

installed temporarily for this purpose. The quick decompression causes a high velocity of air flow in the pipes,

thus removing foreign matters and performing a light erosion on the walls which eliminates rust.

6) For some operations, oil free air/dried air might be needed.


12/19



Date of Issue:


Rev No. :

Fluid

Code

System

Description

Flushing/BlowingFluid

Chemical

Cleaning

Cleanliness Class (SeeNote A,B,C,D)

Remarks

FG Fuel Gas Air/N2 No 450 mg/m2 Note C

HS High Pressure

Steam

Steam No or Yes As per Steam Blowing

Procedure

HR Hot Re-heater

Steam

Steam No or Yes As per Steam Blowing

Procedure

CR Cold Re-heater

Steam

Steam No or Yes As per Steam BlowingProcedure

LS Low Pressure

Steam

Air or Steam No

GS Sealing Steam Air or Steam No

LO Lube Oil Oil No

FO Fuel Oil Water or Air No

FW Feed Water Water No C

CN Condensate Water No C

SM Sampling Water or Air No C

CF Chemical Feed Water or Air No C

MWMark-up Water

Water No C

CC Closed CoolingWater

Water No C

DW De-mineralized

Water

Water or Air No C

TW Permeate Water Water or Air No C

SA Service Air Air No 250mg/m2 Note C

CA Cooling &Sealing Air

Air No250mg/m2

Note C

IA Instrument Air Air No 250mg/m2 Note C

NG N2 Gas Air No 250mg/m2 Note C

CS Co2 Gas Air No 80mg/m2 Note C

HY H2 Gas Air No 80mg/m2 Note C


13/19



Date of Issue:


Rev No. :

6.7 Water Flushing

1) Closed Cooling water piping systems shall be flushed with a circulation of water at velocities greater than

those in services fluid but at a minimum velocity of 1.5 m/sec through the pipe.

2) Chloride content in water for flushing of stainless piping shall be 50 ppm maximum.

6.8 Cleanliness Criteria

1) The degree of cleanliness required of components and systems is in relationship with the function of the

particular component or system after construction.Four classes of cleanliness are provided in this document. Ifno cleanliness class is specified, internal surfaces shall meet the requirements for class D cleanliness as a

minimum.

2) Cleanliness class and criteria for specific system are indicated in Appendix 1 in this document.

Appendix 1- Cleanliness Requirements for Internal of Piping

Fluid

Code

System

Description

Flushing/Blowing

Fluid

Chemical

Cleaning

Cleanliness Class

(See

Note A,B,C,D)

Remarks

SW Service Water Water No D

PW Potable Water Water No C

WO Oily Waste

Water

N/A No

WW Waste Water Water No D

WS Sewage N/A No

FF Fire Water Water No D

RW Raw Water N/A No

XF Vent N/A No

ZZ Drain N/A No

Note

A. Cleanliness to be verified by visual inspection unless specific requirement is described.

B. Vent and drain piping is excluded from the requirements of this specification,

unless otherwise specified.

C. Cleanliness verification for the fuel gas line and other lines require air blowing


14/19



Date of Issue:


Rev No. :

should be as per recommendation.

After internal surfaces have been cleaned and dried, dry smear samples shall be takenfrom representative surfaces of the piping and verified clean to the mg/m2 levelsspecified in the above table.

This verification can be by the optical comparison method of Figure 6 orthe reflectance meter method or equivalent method.

D. Cleanliness class and criteriaClass A

A very high level of cleanliness there is no evidence of contamination of the surface, eitherunder visual examination, with or without magnification, or with the aid of sensitive detectionmethods.

Class A cleanliness is applied to special systems and/or components such as delicate instruments and

other close tolerance or carefully controlled surfaces or assemblies. Such systems or components should

receive their required level of cleanliness at the point of manufacture and cleanliness must be maintained

at the construction site.

Normally any required site cleanliness inspection and/or re-cleaning should only be performed by

suppliers representatives or under the suppliers supervision.

Class BA high level of cleanliness meets the following guidelines.If flushing is the only practical means for

evaluating the cleanliness of internal surfaces, a 20 mesh (850micrometer, ASTM E- 11, Specification for

Wire Cloth and Sieves for Testing Purposes) or finer filter, or the equivalent, shall be installed in the system

or component flushed with water. The system or component shall be flushed at the required velocity until

the screen shows no more than a slight speckling and no more than a slight rust staining. There shall be no

particles larger than 0.8mm by 1.6mm long. In water flushed systems, there shall be no visual evidence of

contamination such as oil or discoloration in the effluent flush water.

Note : Class B cleanliness should be specified for carbon steel and low alloy steel surfaces only in

special cases because of the difficulty in maintaining such surfaces in the condition after the flush.

Class C

An intermediate level of cleanliness in which the surfaces meet the requirements for Class B exceptas follows.

-Thin, uniform rust films on carbon steel surfaces are acceptable.

-Hard rust which forms in a crusty film and tends to break off in pieces or flakes and/or heavy

rusting is not acceptable for carbon steel and must be removed.

Class D

A nominal level of cleanliness the following are acceptable.

-Rust films on both corrosion resistant alloys and carbon steel and low-alloy steel surfaces.

-Tightly adherent mill scale on non-machined carbon and low-alloy steel surfaces.

- Paint or preservation coatings on carbon and low-alloy steel surfaces that will not peel or flake when

subjected to cold water flushing.

- Particles no larger than 1.6mm by 3.2mm on 14 mesh (1.4mm, ASTM E-1 1, Specification for WireCloth

and Sieves for Testing Purposes) or finer filter, or equivalent.


15/19



Date of Issue:


Rev No. :

ATTACHMENT # 1: Piping Line Final Certificate & Pressure Test Certificate (Fuel Gas Line)


16/19



Date of Issue:


Rev No. :


17/19



Date of Issue:


Rev No. :

ATTACHMENT # 2: LEGEND FOR PRESSURE TEST


18/19



Date of Issue:


Rev No. :


19/19



Date of Issue:


Rev No. :

ATTACHMENT # 3: STANDARD DETAIL FOR PRESSURE TEST