Insufficient strength of flange and inner lining at pipeline connection, and short or thin connecting bolts. Hot water pipes use rubber cushions, cold water pipes use asbestos cushions, double-layer cushions or inclined cushions, and flange cushions that protrude into the pipe.
Result: The flange connection is not tight, even damaged, and leakage occurs. When the flange lining penetrates into the pipe, it will increase the water flow resistance.
Method: The flanges and gaskets used in the pipeline must meet the requirements of the pipeline design working pressure. The flange gaskets of heating and hot water supply pipelines should be rubber asbestos materials, and the flange gaskets of water supply and drainage pipelines should be rubber materials. The flange lining cannot be inserted into the pipe. It is advisable to reach the flange bolt hole from the outer circle of the solenoid valve manufacturer. Bevel gaskets or multiple gaskets cannot be placed in the middle of the flange, the bolt diameter of the connecting flange should be less than 2mm of the flange hole, and the length of the protruding nut of the bolt rod should be 1/2 of the thickness of the nut.
In the water pressure strength test and tightness test of the piping system conducted by the valve manufacturer, only the changes in the pressure value and water level of the solenoid valve structure are observed, and the leakage detection is not enough.
Result: Water leakage occurred after the piping system was running, affecting normal use.
Method: When the piping system is tested according to the design requirements and construction specifications, in addition to recording the pressure value or water level change within the specified test time, it is necessary to carefully check whether there is any leakage.