Thursday, August 20, 2015

METHOD STATEMENT FOR ABOVE GROUND PIPE HYDRO TEST...


TABLE OF CONTENTS


1........... SCOPE.
2........... PURPOSE.
3........... DEFINITIONS.
4........... RFERENCES.
5........... RESPONSIBILITY.
6........... HYDROSTATIC REQUIREMENTS.
7........... TEST PREPARATION.
8........... CONDUCTING THE TEST.
9........... INSPECTION.
10......... AFTER COMPLETION OF PRESSURE TEST.
11......... SAFETY.. Error! Bookmark not defined.
12......... DOCUMENTATION.



1                 SCOPE


1.1.                 This Procedure describes the test preparation, line check, safety requirements, examination, test requirements and documentation required for hydrostatic test.

1.2.                 This procedure follows the applicable Saudi Aramco standard  or Owner  and Specification


2.      PURPOSE


The Purpose of this Procedure is to establish the work plan, inspection and test requirements with regards to hydrostatic test for Petrochemical Project. Saudi Arabia.


3.      DEFINITIONS


3.1.           Hydrostatic Test: A pressure test conducted using water or other approved liquid as the test medium. It‘s a proof test / strength test.

3.2.           Service test: A pressure test performed to prove the integrity of pipelines and plant piping using the services fluid at the maximum attainable pressure.

3.3.           Strength Test: A Pressure test at an internal pressure determined in accordance with this standard and the applicable code to verify the integrity of the piping system or equipment for service at the design pressure.

3.4.           Tightness Test: A Pressure test to ensure tightness of the piping system at the test pressure.


4.      RFERENCES


SAEP-302            Instructions for Obtaining a Waiver of a Mandatory Saudi
Aramco Engineering Requirement

SAEP-327             Disposal of Wastewater from Cleaning, Flushing and Dewatering Pipelines and Vessels.

SAEP-1160          Tracking & Reporting of Welding, NDT & Pressure Testing for Capital
Projects

SAES-A-004        General Requirements for Pressure Testing

SAES-A-007        Hydrostatic Testing Fluids and Lay-Up Procedures

SAES-B-017        Fire Water System Design

SAES-L-108         Selection of Valve

SAES-L-109         Selection of Flanges, Stud Bolts and Gaskets

SAES-L-150         Pressure Testing of Plant Piping and Pipelines
     
SAES-L-310         Design of Plant Piping
  
SAES-L-350         Construction of Plant Piping
      
GI-0002-102         Pressure Testing Safety

SAES-A-005        Safety Instruction Sheet

ASME B31.3        Process Piping


5.      RESPONSIBILITY


5.1.           Hydrostatic Testing Coordinator shall be responsible for:
5.1.1.       Preparation and revision of this procedure
5.1.2.       Ensuring all NDE associated with the test package have been fully
              Completed and documented
5.1.3.       Request inspection in accordance with SATIPs related to this Procedure
5.1.4.       Safety of Personnel during testing
5.1.5.       Training workers for hydro testing
5.1.6.       Clear the punch works

5.2.           QC Supervisor & Inspector shall be responsible for:

5.2.1.       Review of this procedure

5.2.2.       Preparation of punch lists and monitoring of punch clearing

5.2.3.       Review of the test package that has been fully completed and documented

5.2.4.       Review of test package for compliance  & inspection of the piping system limits

5.2.5.       Inspection of all pressure tests

5.3.  Field Engineer

5.3.1.       The field engineering team shall be responsible for the composition and distribution of piping arrangement drawings & isometric piping drawings, As-built drawings and the compilation of piping test packages resolution of field changes.


6.      HYDROSTATIC REQUIREMENTS


6.1.           During pressure testing, general instruction GI-0002.102 “Pressure Testing safety” shall be followed and to be included on the pack.

6.2.           The effect of static head of the testing liquid shall be considered when determining the effective test pressure of any elements within the system.

6.3.           Test Fluid

6.3.1.       Water used for testing piping shall be clean water in accordance with SAES-A-007 Para 4.2

6.3.2.       Water quality of intended hydrostatic test waters shall be determined well ahead of the actual testing date so that alternative water source may be identified if the original source water fails to meet requirement.

6.3.3.       Water quality of hydrostatic test waters shall be reconfirmed by testing as close to the time of the hydrostatic test as practicable. In cases where individual tanker trucks are used to supply a test, the water Samples shall be drawn from a representative number of actual truck Loads being delivered to the test site.

6.3.4.       Water used for any part of the hydro test or subsequent lay-up shall be clean and free from suspended matter.

6.3.5.       Water that could result in harm to humans must not be used for hydro test.


6.4.           Protection from overpressure

l All piping system while being hydrostatic tested shall be protected from overpressure by the following:

6.4.1.       Relief valve(s) of adequate capacity set to relieve at 5% above the test pressure shall be installed unless the test pressure is less than 85% SMYS at which time it can be set at 10% above the test pressure. Sizing of these relief valves used for testing shall follow the requirements of API RP520, part 1. The relief valve(s) shall be tested, dated and tagged with one week prior to the pressure test for new construction projects.

6.4.2.       In addition to the pressure relieving device a bleed valve shall be provided to protect the piping from over pressure. The bleed valve shall be readily accessible in case immediate depressurization is required.

6.4.3.       An isolation valve shall be provided between the pressure testing manifold and the system being tested. The isolation valve shall be rated for the manifold test pressure when in the closed position.

6.4.4.       Before employing the pressure testing manifold in the actual system Pressure test, it shall be separately pressure tested to at least 1.2 Times the system test pressure but not less than discharge pressure of the pump used for the pressure testing. Test manifold for new construction shall be revalidated for new project.

6.5.           All newly construction plant piping and prior to initial operation unless exempted by this procedure shall be subjected to a hydrostatic test in accordance with the requirements of this procedure and ASME B31.3 as applicable.

6.6.           Sampling piping system shall be pressure tested as an integral part with the Piping to which it is connected.

6.7.           For piping systems that has already passed 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. In case PWHT is not required and only for the following cased second pressure testing is not required.

l  Seal welds of threaded connections.

l  Attachment welds of non-pressure containing parts, such as wear pads.

6.8.           Drains, vents and piping downstream of pressure relieving devices that discharge directly to the atmosphere with a maximum internal pressure not exceeding 0.69Bar (10Psi) can be excluded from in-situ pressure testing.

6.9.           If block valve(s) are used for blocking or isolating hydro test sections, the Differential pressure across the valve seat shall not exceed the rated seat       Pressure during the tightness test.

6.10.         For internally Fusion Bonded Epoxy (FBE) coated piping system, the test Pressure shall not produce hoop stresses in the pipe that could damage the internal coating. However it shall not be less than the minimum required by the applicable code and shall confirm to company.

6.11.         Hydrostatic Test Package contents as follows:


6.11.1.     Pressure Test Diagram which shall include the limits of piping(including test manifold) included in each pressure test, high points (vent) & low points (drain), location of pressure gauges, test pressure, test temperature, test fluid, safety precautions (shall be appeared in DWG a test symbol legend).

6.11.2.     Relief valve capacity, testing and calibration certificates.

6.11.3.     Pressure gauges and pressure recorders calibration certificates.

6.11.4.     Company safety instruction sheet (for critical piping)

6.11.5.     Test report form (SA-2642-ENG)

6.11.6.     Copies of P&ID and isometric drawings of the piping system to be pressure tested.

6.11.7.     Piping spools control sheet with NDT extent and results.

6.11.8.     Pre-pressure test check list.

6.11.9.     Re-instatement check list.

6.11.10.  Flange set completion documentation for permanent installations.

6.11.11.  Test manifold hydro test verification

6.11.12.  Line list

6.11.13.  Lay-up method to be applied (where applicable)

6.11.14.  Verification of chemical calculations if any

6.11.15.  Test Package shall be submitted for approval for inspection department to Owner at least 7 days prior to the start of the testing.

7.      TEST PREPARATION


7.1.           Site preparation

7.1.1.       This procedure shall be available at the site prior to commencing any hydrostatic testing activities.

7.1.2.       Prior to filling and pressurization the line shall be cleaned in Accordance to a detailed applicable procedure agreed on by  PMT, Proponent and Inspection Agency (SAES-L-350 Para 15.1)

7.1.3.       Soft seated valves and control valves shall not be installed until after the lines have been thoroughly flushed.

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

7.1.5.       Pressure gauges and pressure recorders shall be calibrated before the tests.

l 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.

l All gauges shall have a range such that the test pressure is within 30 to 80% of the full range.

l 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 high point. Their accuracy shall be within 5% of one another.

l When large systems are tested, inspection personnel will determine the need for additional gauges.

l Recording gauges shall be used where it is necessary to keep a permanent record, For example: When the test duration exceeds four hours or otherwise as required by this procedure.

l Pressure and temperature recorders shall be used for 24 hours test.

7.1.6.       Expansion joints and spring hangers or spring support shall be provided with temporary restraints where needed to prevent excessive travel or deformation under the test loads.

7.2.  Isolation of test section

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 by the supervisor, CSD piping unit. When this is not practical, closed block valves (gate, globe, plug and ball) May be used to isolate piping sections provided the valves are not passing, Otherwise the spectacle plate/blind shall be installed in the closed position. If closed block valves are used in lieu of blinds, provisions shall be made to ensure no overpressure can occur in the system that is not being tested due to possible leak through the valves.

7.3.           Vents and drains

7.3.1.       Vents shall be provided at all high points in the tested system as needed.

7.3.2.       Unless the check valve has a by-pass valve, the disc of the check Valve shall be removed and securely attached to the outside of the Check valve prior to the pressure test.

7.4.           Temporary connections and supports

7.4.1.       Temporary connections shall be provided for de-pressurizing and draining of the system to the sewer or disposal area.

7.4.2.       Temporary supports shall be installed prior to hydrostatic testing and Flushing of the piping if they were determined to be required by SAES-L-150. These and flushing of the system to the sewer or disposal area.       

8.      CONDUCTING THE TEST


8.1.           This procedure shall be conducted in accordance with Saudi Aramco applicable code and standard. In addition, the following requirement shall apply.

8.1.1.       Filling and pressurizing shall be injected at the lowest point in the system to minimize entrapped air. When filling at the lowest point is not practical, the inspection department / operations inspection engineering unit shall be consulted. All vents shall be open during filling.
8.1.2.       After the test pressure is reached and before commencement of inspection of the system the isolation valve between the temporary tested manifold. Piping and the piping under pressure test shall be closed and the test pump disconnected. The isolation valve downstream of the manifold shall be opened after the pump is disconnected.

8.1.3.       The pressure shall be maintained for at least 30 minutes ensure that there are no leaks in the system.

8.2.           All piping shall comply with the lay-up procedures per SAES-A-007.
8.3.           Test records shall be recorded on pressure test report form 2642-ENG including applicable SATR and SAIC.

8.4.           Lighting and visual aids

l When performing the test the requirements of ASME V Article 9, T952 – Direct Visual Examination, T953-Remote Visual Examination shall apply.

8.5.           Repair and retest

l When leakage is observed the location of the leak(s) shall be marked. The component shall then be depressurized and the leak(s) repaired as required by the referencing code section. After repairs have been made the repaired area or areas shall be re-tested.

9.      INSPECTION


9.1.           During hydro test all exposed pipe, bolted and welded joints, fittings and valves shall be carefully examined for leakage.

9.2.           The hydrostatic test shall be repeated after the repair of any defects until the system is provided satisfactory.

9.3.           The piping shall be satisfactory if there is no evidence of leakage or pressure loss after the specified test period.

9.4.           Inspection and test plan shall be applied per SATIP-A-004-02 and applicable Saudi Aramco inspection checklist.

10.   AFTER COMPLETION OF PRESSURE TEST


l After hydrostatic testing has been successfully completed and approved by the company’s inspector, the following operation shall be made.

10.1.         Draining of test fluid

l  Water draining and lay-up requirements shall be in accordance with SAES-A-007.

l Release of pressure and draining shall be done on the downstream side of check valves. All vents shall be opened before draining to facilitate drainage and to prevent formation of a vacuum. No test fluid shall remain in low spots.

10.2.         Disposal of test fluid

l The test fluid shall be disposed in accordance with SAEP-327 or as directed by the company.

10.3.         Test vents and drains
l Vents and drains used only for the pressure test shall be plugged seal welded and Penetrant tested.

10.4.         Removal and reconnection of components.

l All temporary items installed for testing purposes (For example: manifold, valves, blinds, spacers and support) shall be removed.

l Items that were removed from testing shall be reinstatement.

l Items, such as instrument air tubing, check valve discs which were disconnected before testing shall be reconnected.

l Isolation valves closed for the test purposes and that are required to be in the open position for process reasons shall be opened. If the valve cavity has a drain, the cavity shall be drained

11.   SAFETY.


l Safety procedure shall be applied to GI-0002-102 (Pressure test Engineering SAES-A-005 (Safety instruction sheet).

11.1.         Only essential personnel are allowed into the designated exclusion zone and they shall be fully aware of safety requirement.

11.2.         Contractor test supervisor shall not allow entry of all personnel into the exclusion zone.

11.3.         The exclusion zone shall be positively identified by placing clear warning signs at all vehicles and pedestrian accesses. If the test pump station is inside the exclusion zone, the test pump station shall be protected.

11.4.         During pressurization, depressurization, contractor test supervisor or designated operator shall remain at the test pump station. All personnel with the exception of the contractor test supervisor and his designated team remain outside the exclusion zone. The Main Contractor test supervisor shall control the entry to the test zone (Company test or safety supervisor shall have right of access to any section of test but must inform to Owner Supervisor). A register of all persons entering the exclusion zone shall be maintained at field office outside of test area by a designated person of Main Contractor test supervisor. All persons shall sign off such register after having completed their activities in the exclusion zone to ensure that all persons have left the prior to proceeding with the next test stage.

11.5.         The compressors and pressure gauge of manifold shall be located in a safe place so that they and the operators and test supervisors are at all times protected either by natural obstacles or temporary barricades.

11.6.         No work shall be carried out on a system while the system is under pressure.

11.7.         A test system under pressure shall never be left un-attended until system is depressurized.

11.8.         When testing at high elevation, strong and safe scaffolding shall be prepared. Ladder or mobile access lift can also used.

11.9.         Control pressure rise

l The pressure rise during a pressure test shall be gradual and control to allow time for material to strain and time for personnel to check for leaks.

l Do not exceed the following pressures until weaknesses have been repaired and leaks have been stopped.

Ø Strength tests using a liquid test medium: 50 percent of the strength test pressure.

l After preliminary checks for leaks at the above pressures the pressure shall be increased in steps with at least 10 minute holds at each step to permit inspection for leaks and weaknesses.

l In strength tests using a liquid as the test medium the pressure shall be increased in steps no greater than (15) fifteen of the strength test pressure after the preliminary check at 50 percent of the pressure.

l Do not proceed to a higher pressure after each of the above steps until weaknesses have been repaired and leaks have been stopped.

11.10.      Depressurize before stopping leaks or repairing

l Working on a system while it is under pressure is very hazardous because a failure could be initiated by the work due to addition of stresses in the material, therefore a system shall be depressurized (With the exception of pressure due to head of liquid) before any work is done to stop leaks or repair weaknesses including the tightening of bolts. In a tightness test, bolts may be tightened without depressurizing if specifically approved in the written procedure.

11.11.      Depressurize Safety

·         Upon completion of the test, the system should be emptied in such a way as not to cause vacuum and collapse. The depressurizing valve and piping shall be arranged for safe discharge of the test medium upon completion of the test. Do not depressurize a system by loosening bolts in a flange or unscrewing fittings because this could lead to injury.
·         Some systems, such as those with heat exchangers may have to be depressurized slowly monitored with pressure gauges to avoid damage to internals such as tube sheets which may not be designed for the momentary differential pressure that could occur with a rapid depressurization.

11.12.      Temporary gaskets shall not exceed the specified rating indicated by manufacturer’s data sheet or spiral round permanent gaskets must be used for those ratings where temporary gaskets are not available.

12.   DOCUMENTATIONS


12.1.         Complete all attachments along with applicable Company Inspection Check lists prior to approval of hydro test package.
12.2.         The hydro test report shall be prepared as per as Company format or  Company approved format.
12.3.         The report shall contain the test system detail. Measuring instruments details, test pressure & duration of test details.
12.4.         The company inspection representative will be signed the report for evidence to witness of the test.





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