How to Protect Abnormal Cavity of Gate Valve
Publisher：Botou Valve
There is a pressure relief hole connected inside the valve to solve the abnormal pressure in the middle chamber and balance the pressure in the middle chamber. Opening the pressure relief hole is the most economical and effective solution. The upstream side gate and the inlet side valve are shown respectively. Pressure relief holes are arranged around the seat. When the chamber pressure rises, the pressure in the middle chamber is automatically released to the upstream side, and the pressure in the middle chamber is always equal to the pressure in the upstream side, thus avoiding abnormal pressure rise.
It shows that the internal valve with pressure relief hole installs external bypass pressure release for the manufactured valve, the external bypass pressure and the external pressure release valve can be used to reduce the pressure in the middle chamber, and the valve installs external bypass pressure release using the upstream side of bypass and bypass with cut-off valve. When the main gate closes, the shutoff valve can be closed to change the temperature of the central chamber. When it is too high, it must be opened.
When the main gate valve is opened, the by-pass cut-off valve should be opened first to reduce the pressure in the middle chamber before starting the main gate valve. Fig. 4 Special relief valve is installed outside the valve. The control pressure range of the external pressure relief valve in the gate valve is shown. The discharge pressure of the relief valve is set to the rated working pressure of the main valve. When the chamber overpressure, it will automatically discharge to the set pressure, thus maintaining the main safe operation of the gate valve.
Fig. 5 shows the structure design of the pressure relief valve for reference. The globe valve is installed in front of the relief valve to facilitate the regulation and overhaul of the relief valve. Pressure setting of pressure relief valves can usually be considered as 1.33PN. PN is the nominal stress of system valves. In addition, when debugging valves, especially when debugging electric valves, attention should be paid to the control of closing stroke and torque.
Reduce closing torque as much as possible to prevent the high temperature valve of wedge gate from considering the thermal expansion of the stem at high temperature. The wedge of the door is wedge-shaped. It is suggested to adjust the large diameter gate valve under high temperature and pressure. When the gate is in place, the stem retracts properly to avoid a real epileptic seizure. Conclusion Abnormal overpressure is the invisible killer of double valve gate valve.
It seriously threatens the safe operation of equipment and system. Attention must be paid to gate valves. Especially for high temperature, high pressure, large caliber gate valve design must consider the occurrence of abnormal overpressure and take it. Necessary precautions?
