Features of hydraulic gate valve

The hydraulic gate valves are widely used in the automatic
control systems and remote control systems, featuring the hydraulically
controlled opening and closing, stable performance and easy operation.
Typical gate valves should never be used for regulating flow, unless
they are specifically designed for that purpose. On opening the gate
valve, the flow path is enlarged in a highly nonlinear manner with
respect to percent of opening. This means that flow rate does not change
evenly with stem travel.
Features of hydraulic gate valve can be summarized as:
1) Hydraulic actuator installed on the top of the bonnet with controls the open and close of the valve by hydraulic pressure;
2) Metal seal between the body and bonnet;
3) Backseat seal between the stem and the bonnet, easy for the change of sealing stuff under pressure; 
4) Sealing surface is hard-faced or the QBQ with the performance of anti-corrosion, wear-resistance;
5) Low operating torque.
From the original1gatevalve
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