The bellows stop valve must be adjusted before installation and put into use, so everyone knows how the bellows stop valve is adjusted! And what do you need to pay attention to when adjusting?

Opening pressure adjustment

Before the bellows globe valve leaves the factory, its opening pressure should be adjusted one by one to the set value required by the user. If the user proposes the working pressure level of the spring, it should generally be adjusted according to the lower limit of the pressure level.

Before installing the bellows shut-off valve to the protected equipment or before installation, the user must re-adjust at the installation site to ensure that the set pressure value of the bellows shut-off valve meets the requirements.



The opening pressure can be adjusted by changing the compression amount of the spring by rotating the adjustment screw within the range of the spring working pressure level indicated on the nameplate.

Before rotating the adjustment 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 adjustment screw is rotated, which may damage the sealing surface.

In order to ensure the accuracy of the opening pressure value, the medium conditions during adjustment, such as medium type and temperature, should be as close as possible to the actual operating conditions. The type of medium changes, especially when the accumulation state of the medium is different (for example, from a liquid phase to a gas phase), the opening pressure often changes. Increase in operating temperature

When, the opening pressure is generally reduced. Therefore, when adjusting at room temperature for high temperature, the set pressure value at room 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.

The conventional bellows globe valve is used to fix additional back pressure. When the opening pressure is adjusted after inspection (the back pressure is atmospheric pressure at this time), its setting value should be the required opening pressure value minus the additional back pressure value.