① Before the Gate Valve leaves the factory, its opening pressure should be adjusted one by one to the setting value required by the user. If the user proposes a working pressure level for the spring, it should generally be adjusted according to the lower limit of the pressure level before leaving the factory.
③ Within the spring working pressure level range indicated on the nameplate, the opening pressure can be adjusted by changing the spring compression amount by rotating the adjusting screw.
④ Before rotating the adjusting screw, the valve inlet pressure should be reduced to less than 90% of the opening pressure to prevent the valve disc from being driven to rotate when the adjusting screw is rotated, thereby damaging the sealing surface.
⑤ In order to ensure the accuracy of the opening pressure value, the medium conditions during adjustment, such as medium type, temperature, etc., should be as close as possible to the actual operating conditions. When the type of medium changes, especially when the accumulation state of the medium is different, the opening pressure often changes. As the operating temperature increases, the cracking pressure generally decreases. Therefore, when adjusting at normal temperature and using it at high temperature, the set pressure value at normal temperature should be slightly higher than the required opening pressure value. How high it is is related to the valve structure and material selection, and should be based on the manufacturer's instructions.
⑥Conventional Gate Valve are used when additional back pressure is fixed. When adjusting the opening pressure after inspection, the setting value should be the required opening pressure value minus the additional back pressure value.