1.1     SCOPE

This document describes the Hydrostatic and Pneumatic Testing Procedure to be applied by company for piping follow codes and client specifications. This testing procedure only applies to shop testing activities.


1.2     PURPOSE

The objective of this work instruction is to give a guideline to the QC Inspector and Workshop’s Foremen/Supervisor to ensure hydrostatic testing is conducted in a safe and efficient manner and in accordance to specification/codes for piping which subject to internal test.



  • ASME B31.3 (*) – Process piping
  • ASME B31.1 (*) – Power piping
  • ASME Section V (*) – Nondestructive examination
  • Client’s specifications

Note: (*) latest edition



Display suitable warnings on the equipment and in the testing areas.

To confirm bolting materials are corrected and met specifications.

Test pump shall constantly attend by experience operator during testing.

Pressure gauge to be monitored by operator during testing.


1.5      TEST MEDIUM

Test medium shall be cleaned or potable fresh water or rust inhibitor.

Chloride content in water shall be less than 250 ppm for carbon steel components.

Chloride content in water shall be less than 50 ppm for stainless steel components.



1.6.1   Production Supervisor

Identify the test medium.

Mark the test limits on the isometric drawing of latest revision and perform the line check.

Locate the pressure gauges, test blinds, vent and drains.

Confirm with relevant QC personnel whether NDEs has been completed and accepted.

Complete the relevant documents as required by the test package.

Orient testing group about handling and usage of testing equipment in order to maintain its measuring accuracy.

Prepare Permit To Work (PTW) for hydrostatic test.


1.6.2   Safety Supervisor

Safety Supervisor shall confirm requirements stated under Section 1.4.

He shall work in-line with the Production Supervisor and QC personnel in fulfilling requirements.


1.6.3   QC Inspector

QC shall inform to the Production Supervisor about the completion and acceptance status of the required NDE.

Review calibration of testing equipment.

Check all applicable joints under pressure for leakage.

Provide welding summaries and NDE reports of the test package.



The test package shall be submitted for approval before testing.

The test package shall include a minimum:

  • A list of all piping spools or equipment.
  • GA drawings, P&ID drawings or Isometric drawings.
  • Test pressure.
  • Test medium.
  • Pressure gauges, pressure recorder, thermal temperature.
  • Pressure test certificate.



  • Test pump.
  • Calibrated pressure gauges.
  • Hose and fittings of required ratings.
  • Chart recorder.
  • Test blinds.


1.9      TEST GAUGES

Pressure gauges shall be calibrated and validated within twelve months.

At least two the calibrated pressure gauges shall use monitoring the test. The first pressure gauges shall locate at lower point where can easily visible for monitoring and another pressure gauge shall locate at the ventilation of higher point.

The range of the gauges shall use within 1.5 to 4.0 times of the test pressure.

A calibrated chart recorder may use during hydrostatic testing for recording.


All examinations and stress relieving activities have to complete before testing.

The Workshop Forman shall ensure all bolts and its nut had tightened.

Barricade must be limited at the testing area with display signboard with “KEEP AWAY HYDROTEST IN PROGRESS”.

Hydrostatic tests will perform by Workshop Forman under supervision of Production Supervisor, QC inspector and/or witness by client,  end users.

The QC inspector shall send the notification to Client before official testing.

The pressure test follows project specification and approval drawings or 1.5 times of the design pressure.

A minimum holding time of test pressure shall be 30 minutes.

The QC inspector shall monitor the testing process and verify that there is no leakage or visual distortion during or upon completion of test.

Upon completion of the test, test medium shall be drained and unbolt flange joint.

All internal pipe spools shall clean and flush with pressurized water, then drying out by dried air



Pressure tests are successful if no leaks, no cracks and no deformations.

If leakage found on products or product welds, their location shall be marked and forward the report to QC Engineer for investigation before re-testing.

If leakage found on flanged joints, threaded joints shall rectify before re-starting test.



The test package includes of a minimum information

  • Client’s job number / project number
  • Job number
  • Duration of hydrostatic test
  • Pressure gauge and recorder
  • Calibration certificate of instruments
  • Date of test
  • Tag name or piping spool number
  • Test medium
  • Test pressure
  • Test temperature
  • Test results


2.1      SCOPE

This document describes the general procedure used for the leak test of piping system requiring this method of leak detection.



  • ASME B31.3  – Process piping
  • ASME B31.1  – Power piping
  • ASME Section V   – Nondestructive examination
  • Client’s specifications

(*) Latest edition



Test medium shall be dried air or nitrogen.

The test package shall be submitted and approved by Client before testing.

Test pressure shall be not less than 1.1 times the design pressure or specification requirements.




2.4.1   Production Supervisor

Identify the test object and test medium.

Locate the pressure gauges, test blinds, vents and drains.


2.4.2   Safety Supervisor

Safety supervisor shall confirm requirements.

He shall work in line with the Production Supervisor and QC personnel in fulfilling requirements.


2.4.3   QC Inspector

Prepare the test package and submit to Client.

Inform the test package to client before testing.

Monitoring the test.


2.5      PRE- INSPECTION     

The test shall be performed by Workshop Forman under the supervision of Production Supervisor, QC Engineer.

All relevant documents shall be reviewed and approved by Client before testing.

Check all valve or equipment to ensure fully open position and correct direction.



Adequate measures for safety and environment control shall be established before test. All required codes and recommendation from principal and or client shall be compiled.

As per pneumatic testing represents special risk, outmost care shall be taken during pressurization and inspection of the system to prevent any danger to personnel or equipment. This task shall be executed under supervision of an experienced Production supervisor.

Tightening of plugs, caps and flange connection is not allowed at pressure above 30% of test pressure. Pressure shall be reduced as required before tightening to carry out.

Testing area shall be marked with warning signs, signboards and to be barricade indicating risk boundaries. Access to test area shall be limited to test personnel only. Unauthorized works shall be away from the testing area.



All relevant authorities have informed (if necessary).

The system or test equipment shall be protected by a pressure relief device having a set pressure of 10% above the pneumatic test pressure of the system.

The system to be tested shall be properly isolated.

All valves are in the opening position.

Liquid detergent soap shall be used for pneumatic testing.

All test pressure gauges shall be calibrated and calibration certificates are available at work site.

Range of pressure gauges shall be not less than 1.5 times or excess than 4.0 times the design pressure.

Minimum of two gauges are required during the test. One gauge should be located at nearest to the inlet pressure application and another at or near to the highest point of the test system.

Temperature of the system or equipment shall monitor and record during the test.



The stage of pressurize or depressurize of test object shall follow fig.- 2

All flange joints and weld seams shall be directly checked by detector solution. Application of the solution shall be in a continuous film relatively free from bubbles. Any indication of bubbles shall be investigated for the location of leakage and retest is required. If it is from the connector point, pressure shall be reduced to zero and repair. If it’s from the weld seam, they shall be dried by using compressed air or gas torch before repairing weld joint. Retest shall be done after weld repairs have cooled down to room temperature.

Test pressure shall be held a minimum of ten minutes or specific in project specification

A pressure relief device shall be provided, having a set pressure not higher than 10% of the test pressure.

No welding shall be performed on the equipment during testing.



The test package includes a minimum of:

  • Client’s job number / project number
  • Job number
  • Duration of hydrostatic test
  • Pressure gauge and recorder
  • Calibration certificate of instruments
  • Date of test
  • Tag name or piping spool ID
  • Test medium
  • Test pressure
  • Temperature
  • Test results


Download: Procedure; Test package; Pressure Test Certificates.



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