PRESSURE LEAK TEST OF CONTROL IMPULSE LINES, INSTRUMENT AIRLINES & PNEUMATIC LINE

TOOLS AND EQUIPMENT FOR LEAK TEST

Tools and equipment needed should be in good condition and must be checked by Instrument Supervisor prior to use. Calibration equipment shall comply with the Saudi Aramco Standards requirements and provided with calibration certificate to support the readings of the calibrating equipment. These includes but not limited to:

• N2 Compressed Gas Cylinder.
• Regulator for N2 Gas.
• Hydro Test Pumps ( In-case of demi water).
• Calibrated Pressure Gauges.
• High Pressure Flexible Hose.
• Common hand tools and other relevant tools.
• Test Manifold included Glove V/V (or needle V/V).
• Snoop/ Soap Solution for leak test.

WORK SEQUENCE / PROCEDURES Pre-Installation Activities

1. Ensure that necessary work permit is obtained prior to proceeding with the work in the area, and are available to working crew. Ensure that all personnel are qualified to perform the testing work and are fully familiar with all the tools and equipment to be utilised. Ensure that all reference drawings, data & specifications, and other relevant documents utilised are approved by Client Company prior to commencing with the work. Ensure that latest revisions of IFC drawings, specifications and approved manuals are disseminated to all concerned personnel involve with the work.
2. Ensure that calibration certificate of all tools and test equipment utilised are still valid, remove and send for recalibration test equipment whose calibration already expired. Check and verify the pressure requirement of the instrument tubing and the piping hook-up to be tested against the pipe line classification. Piping and tubing hook-up which has high pressure requirement will be tested using nitrogen and in some cases by hydrostatic testing.
3. Instrument air lines will be tested using compressed dry air only. Check and verify also the requirement of the equipment/instrument whose tubing and piping hook-up to be tested whether this requires line preservation in which nitrogen only will be utilised as testing medium.
4. Check and verify the instrument location and the pipe and tubing hook-up routing and determine the need for scaffolding/work platforms. Ensure that all tools/equipment needed to perform the work are available at designated areas scheduled for testing. Instrument air system shall be pressure tested following the requirements of SAES-J-901 & SAES-L-150 ( THESE ARE ARAMCO STANDARDS). Water shall not be used.
5. Ensure that consumable materials such as Thread Sealant, Snoop Leak Detector and others are available prior to commencing the testing work.
   • Please read also:  METHOD STATEMENT FOR INSTALLATION OF CATHODIC PROTECTION SYSTEM
6. Pressure test relief valve(s) of adequate set to relief at 5% above the test pressure shall installed unless the test pressure is less than 85% SMYS at which time it can be set at 10% above the test pressure. As per SAES-A-004 para 5.5.1. Pressure relief valve(s) shall be tested, dated, tagged within one week prior to the pressure test. In addition to pressure relieving device, the bleed valve shall be provided to protect the piping and equipment from overpressure.
7. Pressure gauges shall have a range such that test pressure is within 30% to 80% of full range. Pressure gauges calibration interval shall not exceed one (1) month prior to test date and calibration certificate shall be made available to inspection personal prior to commencement of the pressure test. Sticker shall be indicating the latest calibration date.

Testing Procedure Impulse Tubing Leak Test

1. Instrument impulse lines, whether tube or pipe, between the process main block valve and instrument isolation manifold should be tested using the nitrogen gas at times the pressure of the piping system or process equipment to which it connected.
2. Any instrument that could be subjected to damage to test shall be disconnected from the system. Instrument impulse line shall be tested by closed the process block valve and safely assembled main necessary test equipments.
3. As a preliminary test, less than 25% of design pressure shall be supplied to the manifold valve and observing the leaks with pressure gauges used in the test. The test pressure shall be increased to full test pressure and shall be held for at least thirty (30) minutes with observing the leaks with pressure gauge used in the test again.
4. The leaks, which cause the test pressure to decrease more than one graduations on test gauge during the holding time, shall not be acceptable.
5. All impulse line should be cleaned by blowing dry air or nitrogen testing gas before start the leak test. Any observed leakage shall be corrected and re-tested of the system shall be carry out until getting a satisfactory result. After the test, have been completed, the instrumentation shall be identified with a  colour code sticker.

2 Way Manifold

• Close Valves 1, 2, 3 and 8. Open valves 4, 5, 6 and 7 then pressurized the system up to required test pressure (in-case method 1) Close valve 1, 2, 3 and 8. Open 4, 5, 6, 7 and 9 then pressurized the system up to required test pressure (in case method 2).
• Confirm there is no leak by pouring soap water or snoop leak solution on each connection.
• Instrument impulse lines shall be leak tested for at least 30 minutes duration time.
• All instrument process tubing through all drain valves shall be cleaned by air blowing before and/or after the test. De-pressurize the system after the test by releasing the pressure in the De- pressuring valve.
• All tests shall be witnessed by Client Company Representative. After successful completion of each testing, the airline piping shall be marked with a yellow sticker.
• QC inspection and test results shall be filled and recorded in applicable forms.

5 Way Manifold

• Close Valves 1, 2, 3, 4, 5 and 10. Open valve 6, 7, 8, and 9 then pressurized the system up to required test pressure (incase method 1). Close valves 1, 2, 3, 4, 5 and 10. Open valve 6, 7, 8, 9, 11 and 12 then pressurized the system up to required test pressure( incase method 2).  Confirm there is no leak by pouring soap water or snoop leak solution on each connection.
• Instrument impulse lines shall be leak tested for at least 30 minutes duration time. All instrument process tubing through all drain valves shall be cleaned by air blowing before and/or after the test.
• De-pressurize the system after the test by releasing the pressure in the De-pressuring. All tests shall be witnessed by CLIENT Representative. After successful completion of each testing, the airline piping shall be marked with a yellow sticker.
• QC inspection and test results shall be filled and recorded in applicable forms.

 Leak Test for Air Line Piping

1. Close Valves “A”. Open valves B and disconnect the tube at valve regulator I/P side and install OD plug on the tube then pressurized the system up to required test pressured.
2. Bubble leak test shall be carried out for Instrument air tube fittings of I/P regulator side with permanent instrument air at site.
3. Confirm there is no leak by pouring soap water or snoop leak solution on each connection.
4. All instrument air line piping through all drain valves shall be cleaned by air blowing before the test.
5. Leak test for Instrument Air sub headers, blowing of the circuit to be tested, through all drain valves and Air Filter drain, by test medium, as per SATR-J-6001.
6. Note: To avoid dirt, sand, threaded sealant’s liquid material entering into the regulator and positioner.
7. Introduce instrument air to control valve’s regulator/positioned after completing the Blowing Test for Instrument Air Sub-Header piping.
8. Instrument Air sub header lines / instrument air line to individual instrument to be tested at the operating pressure. Instrument process lines to be tested at commodity pressure. During the Pressure Test, all the connections and fittings of the circuit shall be bubble checked with leak detector solution.
9. Vacuum service systems to be checked at 30 PSIG unless limited by a lower pressure design of the line.
10. Test duration shall not less than 30 minutes. Refer to SAES-L-150 para. 5.12.1. De-pressurize the system after the test by releasing the pressure in the De- pressuring valve. All joints which are found defective shall be repaired immediately and be re-tested by the original test method.
11. All tests shall be witnessed by Client Representative. After successful completion of each testing, the airline piping shall be marked with a yellow sticker.
12. QC inspection and test results shall be filled and recorded in applicable forms.

Leak Test for Analyzer Sampling Tube (Bare Tube, Pre-insulated Tube, Bundle Tube, etc.)

1. Close Valves 1 and 6. Open valves 2, 3, 4 and 5. Disconnect the tube at Analyzer side and connect the test pressure with end tube then pressurized the system up to required test pressured. Instrumentation that could be subject to damage due to test shall be disconnected from the tested system. Test pressure shall be set at 1.1 times of design pressure Confirm there is no leak by pouring soap water or snoop leak solution on each connection.
2. Analyzer sampling lines shall be leak tested for at least 30 minutes duration time. All instrument process tubing through all drain valves shall be cleaned by air blowing before and/or after the test.
3. De-pressurize the system after the test by releasing the pressure in the De-pressuring. All tests shall be witnessed by client Representative. After successful completion of each testing, the airline piping shall be marked with a yellow sticker. QC inspection and test results shall be filled and recorded in applicable forms.
4. Leak Test for Utility Connections (Calibration Gas Line, Carrier Gas line, Air supply line, Nitrogen supply line, Cooling Water Connection line, Steam Connection line, Drain tubes and all other Tube and Pipe which related to instrumentation.) Instrumentation that could be subject to damage due to test shall be disconnected from the tested system.
5. Pressurize system up to required test pressure(1.1 times of design pressure) Confirm there is no leak by pouring soap water or snoop leak solution on each connection. All utility connection lines shall be leak
6. tested for at least 30 minutes duration time.
7. All utility tubing through all drain valves shall be cleaned by air blowing before and/or after the test.
8. De-pressurize the system after the test by releasing the pressure in the De-pressuring. All tests shall be witnessed by client Representative. After successful completion of each testing, the airline piping shall be marked with a yellow sticker.
9. QC inspection and test results shall be filled and recorded in applicable.

SAFETY PRECAUTIONS FOR LEAK TEST

1. Barricade the working area.
2. All safety precautionary signboards must be visibly posted.
3. Wear full body harness when working at heights.
4. Ensure that only authorized personnel are within the affected area.
5. The work shall be executed in accordance with the approved Total Safety Task Instructions (TSTI).
6. Maintained TSTI at worksite by work Supervisor, requirements shall be discussed in daily TBT. (See attachment).
7. All Tools and equipment’s used shall in accordance with Safety rules and regulations.