Pressure vessel: pressure test of air pressure test

Test medium  

1. Air pressure test medium should be dry, clean air, nitrogen or other inert gas.

2. The Pressure Vessel with flammable media in use must be thoroughly steam cleaned and replaced, otherwise it is prohibited to use air as a test medium.

Test pressure

1. External pressure vessel and vacuum vessel: resistance test by internal pressure:

test pressure: PT = 1.15P[σ]/[σ]t

2. Hydraulic test pressure should be in accordance with the provisions of the drawings.

Test temperature   

 Carbon steel and low-alloy steel pressure vessel test gas temperature shall not be less than 15 ℃. Pressure vessels made of other materials, the test gas temperature should be in accordance with the design drawings.

Test method

1.Prepare for the air test as required.

2.The unit's security department should be supervised on site.

3.The test should slowly rise to (the rate of pressure can not be higher than 0.2MPa / min) 10% of the specified test pressure, holding pressure for 5-10 minutes, and the initial inspection of all welds and connection parts.

If there is no leakage, continue to increase the pressure (the speed of pressure increase is not higher than 0.2MPa/min) to 50% of the specified test pressure. If there is no abnormality, then step up the pressure by 10% of the specified test pressure (the speed of pressure increase is not higher than 0.1MPa/min) until the test pressure, and maintain the pressure for 30 minutes.

Then lower the pressure (the speed of lowering the pressure is not higher than 0.1MPa / min) to 87% of the specified test pressure, maintaining pressure for enough time to check, the pressure should remain unchanged during the inspection.

Continuous pressurization shall not be used to maintain the same test pressure.

The test pressure should be completed by slowly releasing the gas in the vessel (the rate of pressure reduction is not higher than 0.1MPa/minute).

The sudden release method is not desirable to release the pressure. It is strictly to tighten the bolts under pressure during the gas pressure test.

Air pressure test passing standards

Meeting the following conditions means qualified:

No abnormal sound during the test.

No air leakage by soap solution or other leak detection liquid inspection.

No visible abnormal deformation.