Gate valve installation and use

A gate valve is a cut-off valve, sealing performance is not as good as the globe valve. Gate valve main ‘duty’ is ‘cut off’, as well as to * small resistance: ‘renewed flow’. It should not be used to regulate the flow and pressure of the medium, such as long-term use for regulation, the sealing surface is easy to be flushed by the media wear and tear, affecting the sealing performance. Gate valve medium temperature, pressure, the reliability of the use should be noted. In high temperature, high pressure, due to temperature changes may make the gate wedge, at the same time due to the uneven temperature of the media at all places, easy to produce the phenomenon of non-sealing. Chisel but the gate valve is especially obvious.

Second, the gate valve can be installed in the horizontal pipeline or vertical pipeline, single and double gate valve should be installed in the horizontal pipeline, and the handwheel should be located above the valve, not allowed to be installed downwards. Gate valve media flow direction is not restricted. Gate valve is usually flanged, special occasions are also useful for welding connections.

Third, for large diameter and high pressure gate valve, opening and closing torque is large. In order to reduce the opening and closing torque, can be used to install a bypass valve. Bypass valve is installed in the main gate valve outside, its import and export and the main gate valve on both sides of the practice connection, parallel connection. The main gate valve should be opened before the opening of the bypass valve, into the valve, so that the main gate valve gate before and after the pressure difference is reduced, thereby reducing the main gate valve opening torque. Bypass valve calibre selection should be based on the main valve calibre and use requirements.