Hydrostatic Test Procedure for Pipe

Hydrostatic Test Procedure for Pipe


This document covers hydrostatic test of the piping spool, pipe to vessel to determine general condition and satisfactory operation to the code.

Testing Apparatus

Test pump, hose and fittings connections, test medium, a calibrated pressure gauge to monitoring test pressure, pressure recorder may be used to record variable of test pressure, torch flash for visual inspection of leakage. The pressure gauges and recorder shall be calibrated within 12 months, range of pressure gauge shall not be less than 1.5 times and not more than 4 times.

Safety precautions

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 gauges to be monitored by operator during the test.

Test medium

Test medium shall be cleaned or potable fresh water or rust inhibitor. Note that chloride content in water shall be less than 250 ppm for carbon steel components and chloride content in water shall be less than 50 ppm for stainless steel components.

Test package preparation

The test package shall be submitted for approval include a minimum:

  1. A list of all piping spools or equipment,
  2. GA drawings, P&ID drawings or Isometric drawings,
  3. Test pressure,
  4. Test medium,
  5. Pressure gauges, pressure recorder, thermal temperature,
  6. Pressure test certificate sample,
  7. Calibrated certificates,


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

All raised face of flanges and thread end shall be inspected in good condition and make sure no damaged or deformation.

All connections by bolting, threading shall be tightened and sealed by its nut.

One pressure gauge shall install at a higher point, other pressure gauge(s) shall install at nearly location for monitoring and control by operator.

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

Hydrostatic tests will perform by operator under supervision of Supervisor and QC inspector.

The test pressure shall not less than 1.5 times of the design pressure.

A minimum holding time of test pressure shall at latest 10 minutes.

Temperature measurement of test medium may be recorded during the test.

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

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

All raised face of flange and thread ends shall be properly protected in good condition.

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

Acceptance criteria

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

If leakage found on products or product welds, their location shall be recorded/marked in drawing 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 completion of test package includes:

  1. Client’s job number / project number,
  2. Job number,
  3. Duration of hydrostatic test,
  4. Pressure gauge and recorder,
  5. Calibration certificate of instruments,
  6. Date of test,
  7. Tag name or piping spool number,
  8. Test medium,
  9. Test pressure,
  10. Test temperature,
  11. Test results,

Pressure Test Certificate


please attach form report.

This form in topic Inspection and procedure forms

Thank you for such useful information

Hi Bien,

Do you have a flow chart of hydrostatic test of piping please.

we do not have any flow chart.
As instructed, you may make a flow chart.

Are you agree with me? visual inspection for leakage at above design pressure after depressurizing.

one of factor lead to reduce pressure due to temperature decreased.

Hi Bien it will be very helpful,if you could explain more about

Maximum allowed material / ambient temperature at the time of test.
Pressure drop due to temperature drop (any acceptance criteria).
Safe distance calculation.
Studbolt and gasket type to be used

1 Like

Hi @smitheshsp,
two photos in last topic, the test pressure are accordance to ASME B31.3.

  • Design pressure 22 Bar / Ta at the time of test - 32.6 deg. C
  • Yes, acc. to ASME B31.3, test pressure shall be 1.5 times of design pressure, So, the test items shall withstand at latest 1.5 times specified by code.
    I am not refer other guidelines yet, but the formula regarding relationship of between temperature, volume amount and pressure say yes. I hope that update in next reply.
  • Pressure test calculation as below:

bolting/accessory are applied acc. to the design bolting material - ASTM A193 B7/ A194 2H.