Wednesday, May 6, 2015

Sample Method Statement of Hydro Static Testing for Above Ground Pipe Work...


Table of Contents
1.    Scope ……………………………………………………………………….        

2.    Purpose ……………………………………………………………………. 

3.    Reference ………………………………………………………………….

4.    Responsibility ……………………………………………………………… 

5.    Acceptance standard ……………………………………………………….      

6.    Testing Contractor Supplied Items.…………………………….. ……….. 

7.    Personnel ……………………………………….………………………….. 

8.    Equipment's And Instruments ………………………………………….…. 

9.    Test Gauges ………………………………………………..………………        

10.  Test Records ……..…………………………………………………….….

11.  Test Source Information……………………………………………………  

12.  Test Medium…………………………………………………………………  

13.  Cleaning……………………………………………………………………... 

14.  Hydro Testing Requirements……………………………………………....  

15.  Preparation of Systems for Testing………………………………..……..  

16.  Testing Procedure………………………………………………………….   

17.  Test with Equipment………………………………………………….…....   

18.  Inspection………………………………………………………………..….   

19.  Retests…………………………………………………………………...….. 

20.  Protection from overpressure………………………………….………….   

21.  Dewatering………………………………………………………………..…   

22.  LAY UP of Plant Piping Systems……………………………………..……  

23.  Completion (Reinstatement)…………………………………………..…… 

24.  Safety Requirement………………………………………………………..… 

1.            Scope

1.1 This procedure defines mandatory requirements governing pressure testing of newly constructed plant piping which are designed and constructed in accordance with ASME codes in this Project.
1.2 This procedure covers mandatory requirements for pressure testing existing plant piping for revalidation purposes or after repairs.
1.3 These requirements of this procedure apply to field/shop fabricated piping systems.

2.            Purpose
The purpose of this procedure is to determine the method of hydro static testing for (above ground) pipe work by Contractor.

3.             Reference
·         ASME B31.3  
·         SAEP 327
·         SAEP-1028
·         SAES-116
·         SAES-L-150
·         SAES-L-350
·         SAES-A-004
·         SAES-A-007  
·         SATIP-A-004-02
·         SAIC-A-2001
·         SAIC-A-2009
·         SAIC-A-2013.
·         SAIC-A-2015
·         SAIC-A-2017
·         SAIC-A-2003
·         SAIC-A-2007
·         SAIC-A-2008
·         SAIC-A-2010
·         SAIC-A-2016
·         SAIC-A-2018
·         SAIC-W-2010
·         SATR-A-2001
·         SATR-A-2009
·         SATR-A-2014
                                 






4.            Responsibility

4.1       Erection-Installation Engineer/Supervisor.

·         Responsible for ensuring that the field installed piping as per the applicable drawings and specifications.
·         Responsible for identifying and arranging the materials required before the final release for hydrostatic test.
·         He should monitors the safe working practices during testing and ensure the safety for both testing and non-testing personnel.
            4.2       QC-Engineer.

·      Responsible to ensure that the pipe is installed with threaded holes and reinforcement pad for hydrostatic test during fit-up clearance stage.
·      Responsible to ensure that the NDT as applicable is done before and after pipe welding and shall witness pipe hydrostatic test.

4.3       HSE Supervisor.

·      Shall advice and assist the personnel involved in executing the hydrostatic test.
·      Monitor the testing activities to confirm all project safety procedures/practices.


5.            Acceptance Standards

5.1      No leaks on each part of the item under test are permitted.
5.2      No permanent deformations are permitted.
5.3     No leaks from hydro test devices directly connected to the item that can mask leaks on item are permitted.

6.            Testing Contractor Supplied Items

All tools and equipment required for piping system pressure tests. Including pumps, compressors connecting pipe work with strainers and storage reservoirs pressure gauge, temporary blinds, plugs, spools, vents and drains, piping equipment gaskets required for test purposes etc., shall be supplied by the Main Contractor.








7.            Personnel

QTY
DESCRIPTION
2
Test engineer
2
Pump operator
1
Driver
10
Test technician


8.          Equipments and Instruments


QTY
Equipment
3
Filling pump
1
Pressurizing pump
3
Water tanker
1
Hydraulic stud bolt pensioner
1
Torque wrench
Lot
Temporary valves (1/2” – 1” – 2”)
Lot
Temporary fittings (1/2” – 1” – 2”)
Lot
High pressure hose (1/2”– 2”)
8
Pressure gauge
1
Pick-up
2
Tool set






      The following list defines the equipment that shall be excluded from the in-situ pressure testing of the tested system.  Also, other unlisted sensitive equipment or as designated by Client/ Inspector can be added:
       a)      Rotating machinery, such as pumps, turbines and compressors;
       b)      Strainers and filter elements;
         c)   Pressure relieving devices, such as rupture disks and pressure relief valves;
       d)     Locally mounted indicating pressure gauges, where the test pressure will      exceed   their scale range;                 
       e)     Equipment that cannot be drained; 
        f)     Instrument Devices.


9.       Test Gauges

9.1      On small single level system, less than 40 m long, one pressure gauge will be used, on other systems two pressure gauge will be used all pressure gauges shall be calibrated by dead weight tester  ever month and certificate  will be signed by client rep. 
9.2       Pressure gauges and pressure recorders shall be calibrated before the tests.
9.3     The calibration interval shall not exceed one (1) month calibration certificates shall be made available to inspection personnel prior to commencement of the pressure test, stickers shall be applied indicating the latest calibration date.
9.4      All gauges shall have a range such that the test pressure is within 30 to 80% of the full range.
9.5    A minimum of two pressure gauges are required for the test system. One pressure gauge shall be on the test manifold and the other(s) on the test system. Their accuracy shall be within 5% of another.
9.6     Recording gauges shall be used where it is necessary to keep a permanent record, e.g. when the test duration exceeds four hours.


10.          Test Record

10.1    Records shall be made for each system tested which shall include:
           A) Date of test.
           b) Identification of piping test.
           c) Item (serial number, drawing, etc.).
            d) Cross reference to test gauge certificate.
            e) Test medium.
            f) Test pressure.
            g) Test duration.
            h) Results of test.
            i) Approval by the inspector.
10.2    Records for piping which require that pressure be held for a specified period of time shall include any corrections of test pressure due to temperature variations between the start and finish of the test.
10.3    Records for piping in which a specified leakage rate is permitted shall include the time at which water was added and the quantity added.
10.4    All test records and authorized inspectors certifications shall be retained in the job records.


11.          Test Source Information

·           Line Designation Tables (LDT'S). The ltd's shall be the controlling documents in determining the type of test, test medium and test pressure.
·           The line Designation Tables indicate (in the mechanical data section) the line number, description, piping material service class, design pressure, design temperature, insulation and tracing requirements and minimum test pressure for each line, the type of pressure test and test medium, if other than hydrostatic.


12.          Test Medium

·           Sea water shall not be used for hydro testing unless approved by Client and other related Local  authorities.    
·           Clean, fresh water free of suspended solids and other foreign matter shall be used for hydrostatic testing of carbon steel piping; water chloride content shall not exceed 300ppm.
·           Demilitarize water shall be used for testing low alloy, austenitic stainless steel and nickel alloy steel piping ( not more than 50ppm chlorides).
·           Potable water (drinking water and raw water) piping systems shall be hydro tested with fresh potable water.
·           Other utility piping systems shall be hydro tested with potable water.   
·           No thermoplastic piping shall be pressurized until it has cured for 24 hours at a surface temperature of 10◦c or higher, or for 48 hours at surface temperature 10◦c.
·           The test pump shall be placed on firm ground away from the piping, the pump and the piping system (piping and equipment) shall be protected from overpressure by relief valve(s) of adequate capacity.
·           Gravity sewers shall be tested from manhole to manhole, or manhole to sump inlet. The upstream manhole may be tested at the same time.


13.          Cleaning

Prior to hydro-test activity starts, Internal cleaning will be done by using a compressed air till the line is free from any dust or any other materials such as gloves, electrodes, sand …etc.                                                                                            


14.          Hydro Testing Requirement

Components in new piping systems which interfere with filling, venting, draining or flushing shall not be installed until after line flushing and pressure testing are completed.  These include orifice plates, flow nozzles, sight glasses, venturies, positive displacement and turbine meters and other in-line equipment.

14.1 General Requirements

·                The effect of the static head of the testing liquid shall be considered when determining the effective test pressure of any elements within a tested system.
·                Relief valve calibration duration shall not exceed one week.
·                Test pressures and test durations shall base on the applicable Aramco standards.
·                Hydrostatic testing duration shall be 24 Hours recorded test for un-exposed joints piping system.


15.          Preparation of Systems for Testing

15.1       Isolation of test sections:
           Paddle blinds or spectacle blinds shall be used to isolate the test sections. They shall be the same class rating of the system or may be fabricated based on appropriate calculations. When this is not practical, closed block valve (gate, globe, plug, and ball) may be used to isolate equipment or piping sections (provided the valves are not passing. If closed block valves are used in lieu of blinds provisions shall be made to insure no over pressure can occur in the system that is not being tested due to possible leak through the valves.
15.2    Temporary blind flanges and test blinds used to isolate a test system shall be of an adequate thickness to withstand the test pressure.
15.3    Instrument connections shall be closed with a properly gasket blind flange, or with a threaded plug.
15.4   All system to be tested must have vents at highest points and drains in the lowest point.
15.5   Control valves, thermo wells, orifice plates, strainer baskets, filter elements, expansion bellows, in line, instruments and all other in line components shall be removed and replaced with temporary spools spacers.
15.6   All piping shall be accessible during test shall not be insulated, backfilled or otherwise covered until satisfactory completion of testing.
15.7   Valves except socket weld valves shall not be used to isolate a test system except for lines not pressurized in service.
15.8    If the pressure is to be applied downstream of check valves, the valves shall have their internals removed.
15.9     Expansion joints shall not be included in pressure tests.
  15.10  The test rig shall be provided with relief valves of adequate capacity to contain the system at not more than 10% above the specified test pressure.
15.11  The test pressure gauge shall be located at the high point of system pressure gauges shall have current certification of accuracy.
15.12 Strainers shall be included the piping system and care shall be taken to ensure that dirt and debris cannot be forced into instrument branches or pockets in lines.
15.13 All piping shall be accessible during test and shall not be painted insulated, backfilled or otherwise until satisfactory completion of testing in accordance with this specification.


16.          Testing Procedure (Hydrostatic Test)

16.1       The manifold shall be separately pressure tested at least 1.2 times the system test pressure but not less than the discharge pressure of the pump used for the pressure testing.
16.2       Adequate vents shall provide at all high points of the being tested to facilitate purging air pockets during filling.
16.3       The test pressure shall be gradually applied to minimize any shock effect on the system under test; the application of pressure shall be carefully controlled to prevent any over pressurizing of the piping.
16.4       Upon completion of hydro static test, the pressure shall be gradually reduced to zero.
16.5       Before draining of the testing medium, high point vents shall be opened to avoid the imposition of a vacuum in the piping system and to prevent any collapse.
16.6       Prior to filling the system with the test medium, the system shall be inspected for fabrication completeness and satisfactory test preparation, including the placement of pressure gauges and suitability of the test rig.
16.7       After completion of flushing the area around the system under test shall be cleared of unauthorized personnel and warning notices posted during the time that the piping system is pressurized for the test. The arrangements made to exclude unauthorized personnel, and the perimeter of the hazard zone, shall be agreed with the inspector.
16.8       Liquid testing medium shall be introduced at the system low point to avoid air pocket formation vents at high points shall be left open and not closed until test medium flow from the outlet all air must be removed before pressure greater than the required to fill the system is applied.
16.9   Hydro static testing with water as a test medium shall not be performed when there is a falling air temperature of 5◦c or less. Should these conditions occur during a test, the test shall be aborted and the system depressurized.
16.10    Hydro static pressure testing shall not commence until the test fluid temperature is in equilibrium with the pipe work system. The rate of pressure increase in approaching the test pressure shall not exceed 4.83 brag per minute.
16.11  For hydro static tests, pressurize to the specified test pressure and hold for a sufficient length of time to allow piping to equalize strains. The test pressure shall be held until all joints (threaded, socket-weld, butt welded and flanged) have been inspected for leaks, but in no case for less than the following:
Shop fabricated spool 30 minutes final line hydro test for systems with test pressure below 35.5 barg. 1 hour.
Final line hydro test for systems 35.5 barg and higher. 2 hours.
16.12    Upon completion of hydrostatic test, the pressure shall be gradually reduced to zero.
 16.13    Before draining of the testing medium, high point vents shall be opened to avoid the imposition of a vacuum in the piping system and to prevent any collapse.
          16.14 Conversely if the test is started during the cool part of the day and the pressure increase increases beyond the test pressure due to the increase in temperature, then the system will have to be periodically relieved back to the test pressure. The total time that the line is held at the required test pressure should not be less than that indicated above. If the pressure holds then the test is complete.
 16.15   There shall be no testing at night or in the rain.


17.          Test with Equipment

Connecting piping is not to be tested through equipment unless approved by the Client/ Consultant.


18.          Inspection

18.1       During hydro test, all exposed pipe, joints, fittings, valves, and hydrants shall be carefully examined for leakage.
18.2   The hydrostatic test shall be repeated after the repair of any defects until the system is proved satisfactory.


19.          Retest

If a line does not meet the test, any leaks or defects must be repaired; lines must be depressurized before tightening threaded connections and drained before starting any weld repairs. No leaking forged-steel screwed connections may be seal-welded without specific approval. The repaired line shall be retested at the pressure originally specified.


20.          Protection from Over pressure

20.1       All systems while being pressure tested shall be protected from being over pressured by Relief valve(s) of the adequate capacity set to relief at 5% above the test pressure.  
20.2       All systems while being pressure tested shall be protected from being over pressured by relief valve(s).
20.3       Every pipeline, after construction and prior to initial operation shall successfully pass a hydro static test.
20.4       Every existing plant piping after repairs or alterations have been made that affect the integrity of the pressure containing parts shall successfully pass a hydro static test.
20.5       For piping systems that has already a successful pressure testing a second pressure testing is required if it is subjected to new welding activities and post weld heat treatment (PWHT) is mandated due to these new welds.
20.6       In case PWHT is not required and only for the following cases second pressure testing is not required.
20.7       Seal welds of threaded connections.
20.8       Attachment welds of non-pressure containing parts, such as wear pads.
20.9       Piping such as drains, vents and piping downstream of pressure relieving devices that discharge directly to the atmosphere.


21.          Dewatering

21.1       During dewatering the loop all vents shall be open position.
21.2       Water will be completely drained at safe location with arranging with Aramco.
21.3       Blowing the completion of loop dewatering, flushing will be carried out using an air compressor.
21.4       All temporaries will be removed and all line elements will be reinstated.
21.5       Immediately following completion of all operation, the test certificate will be signed by Sun Con QC Mechanical, Contractor QC and  Client QC.
21.6       All gaskets used with temporary blinds or spades shall be replaced.
21.7       Water disposal of loops by return test water to tanker as passable.
21.8       Water disposal plan will be achieved according to SAEP- 327.


22.          Lay up of Plant Piping System

·         Dry layup process by using dry air.
·         Dry layup with dry air (dew point - 1◦c or less). Repeat flushing until cleanlines is verified by observing the absence of any solids impact on a polished metal target at the exit.


23.          Completion (Reinstatement)

23.1    Then the tests are completed all blanks and blinds, shall be removed all valves, expansion joints, filter elements, and other components removed for the test shall be re installed.
23.2       Temporary test valves shall be replaced with line class plugs.
23.3  Plugs shall be seal-welded where required by piping fabrication and erection specification; finally, temporary supports and spring hanger gages shall be removed.
23.4       Permanent gaskets and bolts shall be installed.
23.5       The Contracto inspector shall sign the reinstatement certificate.




24.          Safety Requirement

24.1      All personnel involved in testing operation shall wear full PPE including hard hats, safety boots, and gloves to be worn by mechanical operation.
24.2       The test equipment will be located in a safe position.
24.3       Warning signs will be erected outside the cordoned off area.
24.4       No personnel will be allowed to work within 30 mt. Of the pipe while testing operations are in progress.
24.5       The tested system shall not never be lifted without attendance.

24.6       If during pressurizing or test holding time leaks are located , the pressure will be bled down to zero pressure head and leak rectified , no tightening of flanges will take place while system is under pressure. 


 HYDRO STATIC TEST ACCEPTANCE CERTIFICATE MODEL.
       
TEST SYSTEM :
TEST PACK.NO. :
NOMINAL DIAMETER  :
MATERIAL CLASS  :
ISOMETRIC NO.
P&ID DIGRAM :
TEST MEDIUM  :
AREA :
TEST PRESSURE :                                            BAR
TIME :                                HOUR                      FROM                          TO
PRESSURE ( ACTUAL )                                    BAR
HYDROTEST ACCEPTED                                 REJECTED

1.GAUGE NUMBER                                           EXPIRY DATE


Sub Contractor
Name :
……………………………….
Sign.  : ……………………………….
Date  : ……………………………….
Contractor
Name : ……………………………….
Sign.  : ……………………………….
Date  : ……………………………….
Client
Name : ………………………………
Sign.  : ……………………………….
Date  :  ……………………………….

PREPARED BY : M.AJMAL KHAN.

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