Shell test and leakage test
1.The medium for shell test and leakage test of the screw gate valve includes water(containing presservatives),kerosene or other kinds of suitable liquid with a viscosity not larger than water.
2.For the screw gate valve with the seal pair adopting non-metal seal,the leakage and shell tests and requirements conform to provision of GB/T13927-92D.
3.Regarding the screw gate valve with the seal pair adopting metal seal,the leakage quantity for the leakage test is calculated by 1×DNmm3/s for those with requirements for sealability and no such provision for those without requirements for sealability.
4.For those screw gate valves provided with electric,hydraulic or pneumatic actuators,shut three times after the off position is set and then carry out the shell and leakage tests in accordance with requirements in 1 and 3.
5.The requirements for cleanness of the screw gate valve conform to provisions of JB/T7748.
6.Static pressure lift test.
7.The times for static pressure test of the screw gate valve are subject to the provisions and other technical requirements to provisions of JB/TZ234.
2.For the screw gate valve with the seal pair adopting non-metal seal,the leakage and shell tests and requirements conform to provision of GB/T13927-92D.
3.Regarding the screw gate valve with the seal pair adopting metal seal,the leakage quantity for the leakage test is calculated by 1×DNmm3/s for those with requirements for sealability and no such provision for those without requirements for sealability.
4.For those screw gate valves provided with electric,hydraulic or pneumatic actuators,shut three times after the off position is set and then carry out the shell and leakage tests in accordance with requirements in 1 and 3.
5.The requirements for cleanness of the screw gate valve conform to provisions of JB/T7748.
6.Static pressure lift test.
7.The times for static pressure test of the screw gate valve are subject to the provisions and other technical requirements to provisions of JB/TZ234.