Wenzhou Unique Valve Co., Ltd.
Dos and Don'ts for Valve Pressure Tests (Part Two)
Jan 14, 2021
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(8) The closure member of the throttle valve shall not be tested for leakage, but the strength test shall be done, and the leakage test at packing and the gasket shall also be performed.
(9) During pressure test, only one person's normal force can be allowed to close the valve. Do not apply force with tools such as the lever (except the dial torque wrench). When the diameter of the handwheel is greater than or equal to 320mm, two people are allowed to close the valve together.
(10) The valve with the back seat should be tested for leakage after the packing is taken out. After the back seat is closed, check the valve for leaks. When testing the valve with gas, fill the packing box with water for inspection.
(11) Valves with driving devices shall be tested for leakage after the valves are closed with the driving devices. For valves with manual driving equipment, the leakage test should be done after the valves are closed manually.
(12) For the bypass valve installed on the main valve after the strength test and leakage test, the strength test and leakage test of the bypass valve should be done again on the main valve. When the closure member of the main valve is opened, that of the bypass valve should also be opened.
(13) During the strength test of cast iron valves, tap the valve body and the bonnet with a copper hammer to check whether there is any leakage.
(14) When the valve is tested, the sealing surface of the valve is not allowed to be oiled except the plug valve.
(15) During the pressure test of the valve, the snap-in force of the blind ram on the valve should not be too large, so as to avoid deforming the valve and affecting the test effect (If the cast iron valve is pressed too tightly, it can also be damaged).
(16) After the valve pressure test is completed, the stagnant water in the valve shall be removed and the valve should be wiped clean in time. The test record shall be made.
(9) During pressure test, only one person's normal force can be allowed to close the valve. Do not apply force with tools such as the lever (except the dial torque wrench). When the diameter of the handwheel is greater than or equal to 320mm, two people are allowed to close the valve together.
(10) The valve with the back seat should be tested for leakage after the packing is taken out. After the back seat is closed, check the valve for leaks. When testing the valve with gas, fill the packing box with water for inspection.
(11) Valves with driving devices shall be tested for leakage after the valves are closed with the driving devices. For valves with manual driving equipment, the leakage test should be done after the valves are closed manually.
(12) For the bypass valve installed on the main valve after the strength test and leakage test, the strength test and leakage test of the bypass valve should be done again on the main valve. When the closure member of the main valve is opened, that of the bypass valve should also be opened.
(13) During the strength test of cast iron valves, tap the valve body and the bonnet with a copper hammer to check whether there is any leakage.
(14) When the valve is tested, the sealing surface of the valve is not allowed to be oiled except the plug valve.
(15) During the pressure test of the valve, the snap-in force of the blind ram on the valve should not be too large, so as to avoid deforming the valve and affecting the test effect (If the cast iron valve is pressed too tightly, it can also be damaged).
(16) After the valve pressure test is completed, the stagnant water in the valve shall be removed and the valve should be wiped clean in time. The test record shall be made.
