HYDROSTATIC TESTING
DOC NO: SA/QC/PH/04
Rev
:01
Page :1 OF 4
METHOD STATEMENT FOR
HYDROSTATIC TESTING
HYDROSTATIC TESTING
DOC NO: SA/QC/PH/04
Rev
:01
Page :2 OF 4
1. OBJECTIVE
To define pressure testing requirements of pressure vessels, boilers and piping spools in
accordance with applicable Code requirements.
2. SCOPE
This procedure is applicable for the shop pressure testing (hydrostatic test only) of pressure
vessels, boilers and piping components (spools). When required, a separate procedure shall
be established for Pneumatic testing taking into account all the requirements of applicable
Codes.
This procedure does not cover the requirements for carrying out pressure tests at field sites
where a specific procedure shall be developed depending on the type of field work involved.
3. APPLICABLE CODES

ASME Code Section VIII Division 1
4. PREPARATION FOR TEST
4.1.
Ensure that the item is ready for pressure test and all examination and inspection
activities required to be completed prior to pressure tests have been satisfactorily
completed and where required, acceptance has been obtained from Client/TPI.
4.2.
Ensure that all applicable non-conformities have been satisfactorily resolved and
closed.
4.3.
Ensure that the item under test contains no foreign objects and is properly supported
for the test.
4.4.
Prepare and close the openings using suitable closures capable of withstanding the
test pressure except for the upper most nozzles, which shall be closed only after it is
ensured that the vessel is fully filled with the test medium. Install suitable pressure
gauge, vent, drain and pressurizing connections.
5. TEST MEDIUM & FILLING
5.1. Test medium for carbon and low alloy steel shall be potable or town water unless
vessel specific requirements are identified in the ITP or drawing.
5.2. Test medium for stainless steel or other high alloy steel shall be water with chloride
contents not exceeding 50 pm. Contract specific requirements if any shall be identified
in the ITP or drawings.
5.3. When required by the contract specifications, suitable inhibitors shall be added to the
test medium.
HYDROSTATIC TESTING
DOC NO: SA/QC/PH/04
Rev
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5.4. During filling and vent all high points to ensure that item under test is completely filled
with the test medium and to purge possible air pockets.
5.5. All low pressure filling lines shall be disconnected or isolated by valves or other
suitable means after filling and venting is completed.
6. TEST GAUGES AND RECORDERS
6.1.
Location
A minimum of two nos. calibrated pressure gauges with proper assembly valves shall
be attached to the item under test such that the gauges are clearly visible to the
operator who is pressurizing the system. At least one gauge will be mounted close to
the highest point on the item.
6.2.
Range
The range of pressure gauges shall be about double the intended test pressure but in
no case it shall be range be less than 1.5 nor more than 4 times the intended test
pressure.
6.3.
Gauge Calibration
All test gauges shall be calibrated at least every year (or earlier if there is a reason to
believe that the gauge is not accurate) as per the calibration system against a Dead
Weight Tester or a Calibrated Master Pressure Gauge. The maximum permissible
error shall not exceed ± 1.5% of the full scale reading.
7. TEST TEMPERATURE
7.1. For U and U2 items, it is recommended that the metal temperature during test be
maintained at least 30 °F (17 °C) above the minimum design metal temperature to
minimize the risk of brittle fracture. The permissible test temperature is specified on the
drawing.
7.2. If the metal temperature during test exceeds 120 °F (50 °C), it is recommended that
close examination of the item under test be delayed until the temperature is reduced to
120 °F (50 °C) or less.
8. TEST PRESSURE – UPPER LIMIT AND STRESS DURING TEST
8.4. The test pressure shall be based on the applicable requirements of the Code and shall
be specified on the drawing.
HYDROSTATIC TESTING
8.5.
DOC NO: SA/QC/PH/04
Rev
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Direct sunlight on equipment can cause an increase in temperature resulting in an
increase of pressure during the holding time. If this condition exists, pressure is to be
monitored and vented as necessary.
9. APPLICATION OF TEST PRESURE, HOLDING TIME & EXAMINATION
9.1.
The pressure shall be gradually increased until the required pressure has been
reached. Once the pressure has been achieved and stabilized (for about ten minutes)
the pressurizing system must be isolated from the pressure source.
9.2.
The minimum holding time at test pressure shall be specified on the drawing/QIP.
9.3.
Close examination shall be carried out on all welds and the regions of high stress
such as head knuckles, areas around openings and thickness transition areas. The
following is recommended for close examination during test:
a. For ASME Code Section VIII Division 1, the close examination is made at the
pressure not less than test pressure divided by 1.3
9.4.
Upon completion of the test, the pressure shall be gradually reduced to zero before
opening the drains.
10. ACCEPTANCE CRITERIA
The pressure test shall be considered as acceptable when there is no evidence of leakage
and there is no visible deformation on any component
11. HSE INSTRUCTIONS
The following safety precautions shall be taken during the test:

Cordon-off the test area and put warning signs as necessary

Only authorized personnel are allowed inside the cordon-off area.

The test is continuously monitored during the test by a competent personnel

Provide proper access (scaffolding/ladder) to all parts of the vessel for close
examination

All authorized personnel to wear adequate personal protective equipment during the
test.
No hammering/grinding/welding work is permitted when the item is under pressure

12. Related Documents
Hydrostatic Test Certificate
Gauge Calibration Certificate