The principle and structure of hydraulic control valves
Hydraulic control valve is a pipeline medium pressure as the power, which can adjust the opening and closing, the valve gate. It consists of a main valve and attached catheter, needle valve, ball valve and pressure gauge, etc door, depending on the purpose of use, function can be turned into a remote control float valve door, and pressure relief valve, slow close check valve, flow controller, pressure relief valve, hydraulic electric control valves, emergency shut-off valve, etc. Guide valve along with the change of liquid level and pressure of medium action, because the pilot valve is a lot of more phyletic, can be used alone or several combination, can give the main valve of water level and water pressure and flow rate of single and compound adjustment function. But the main valve valve body similar cut-off valve, gate valve fully open, the pressure loss is much bigger than other valve door, and all the more opening loss coefficient and full close state, close to the surge, the bigger the valve gate diameter is more significant. Has the characteristics of the valve gate, near the valve disc movement speed, prone to the impact of water hammer, close to full close valve gate as slowly as possible, so the throttle device can be installed on the valve disc. Another pilot valve throttle and action to avoid setting of small-bore orifice, in order to avoid congestion. When it is necessary to add filter, preventive maintenance, and set the by-pass pipe. Hydraulic control valve diaphragm type and piston type two kinds, the working principle of the same, is more than the downstream pressure difference, pilot valve control, make diaphragm ( The piston) Hydraulic differential operation, entirely by hydraulic automatic adjustment, so that the main valve disc valve fully open or fully closed or in a state of adjustment. When entering the diaphragm ( The piston) Pressure of control room above the water is discharged into atmosphere, or low pressure area downstream effect under lower valve disc and diaphragm pressure value is greater than at the top of the pressure value, and thus pushes the main valve flap valve to the fully open position: when entering the diaphragm ( The piston) Of control room above the pressure in the inlet pressure and export since the middle, the main valve disc valve is in a state of adjustment, adjust the position depends on the catheter needle valve in the system and the guide joint control function of the valve. Guide valve to open or close by the change of the downstream pressure of their own small valve port, thus changing the diaphragm ( The piston) Above the control room of the pressure value, the adjustment of the main valve flap valve position control. Can be used for drinking water and industrial water supply system, fire control system.