(1) In general, the valve is not tested for strength, but after the repair of the valve body and bonnet or corrosion damage to the valve body and bonnet should be strength test. For safety valves, the pressure and return pressure and other tests shall comply with the provisions of their instructions and relevant regulations.

 (2) the installation of the valve should be for the strength and sealing test. Low-pressure valve checks 20%, such as failure should be 100% inspection; medium and high pressure valves should be 100% inspection.

 (3) When testing, the valve installation position should be in the direction of easy inspection.

 (4) welded joint form of the valve, with the pressure board can not be used when the cone seal or O-ring seal pressure test.

 (5) hydraulic test will be the best way to exclude the valve air.

 (6) test pressure to gradually increase, not allowed to sudden, suddenly pressurized.

 (7) strength test and sealing performance test duration is generally 2 ~ 3min, important and special valves should last 5min. Small caliber valve test time can be correspondingly shorter, large caliber valve test time can be correspondingly longer. In the course of the test, if in doubt can extend the test time. Strength test, do not allow the body and the valve cover sweating or leakage phenomenon. Sealability test, the general valve only once, safety valve, high pressure valve and other raw valves need to be carried out twice. In the case of tests, low pressure, large diameter unimportant valves and valves that are permitted to allow leakage are allowed to have a trace of leakage. Due to the requirements of common valves, power valves, marine valves and other valves, Should be implemented in accordance with the relevant provisions.

 (8) Throttle valve is not closed Closed test, but should be strength test and packing and gasket at the sealing test.

 (9) test pressure, the valve closing force allows only one person's normal physical strength to close; not with the lever of tools such as force (except torque wrench), when the hand wheel diameter is greater than or equal to 320mm, allowing two common shut down.

 (10) with the seal on the valve should be taken out of the filler for the seal test, the seal on the official, check whether the leakage. When testing with gas, check in the stuffing box. For the packing sealability test, the upper seal is not allowed to be in the sealed position.

 (11) Where a valve with a drive device is tested for its seal, the drive is used to close the valve against the sealing test. For manual drive, it should also be used to close the valve seal test.

 (12) Strength test and seal test After installing the bypass valve on the main valve, the main valve for strength and sealing test; the main valve closing parts should also be opened.

 (13) cast iron valve strength test, the application of copper hammer tapping the valve body and valve cover to check whether the leakage.

 (14) valve test, in addition to the provisions of the plug valve to allow sealing oil, the other valves do not allow oil on the sealing surface test.

 (15) valve pressure test, the blind plate on the valve compression force should not be too large, so as to avoid deformation of the valve, affecting the test results (cast iron valve if the pressure is too tight, but also damaged).

 (16) valve pressure test is completed, the valve should be promptly removed and wipe clean, but also make a good test record.