The hydraulic valve device precision & advantages and disadvantages

Appearance of Pneumatic Butterfly Valves, the main difference is that they rely on the power source of the drive. Hydraulic valve stand hydraulic power source, the higher oil pressure to push the piston to drive the valve switch. The precision requirements of the hydraulic actuator is very high, a little a bit processing undeserved cause hydraulic oil leak, the oil cylinder is likely to be scrapped. Is the cause of hydraulic pneumatic valve price is expensive. Hydraulic valve output torque relative to the pneumatic valve, power is strong. Hydraulic valves are widely used in water, steam, water, paper, petrochemical, natural gas, solution and pulp two-phase mixed flow medium, and the dust and gas, powder conveying solid medium containing particles fluid is the ideal equipment, using the hydraulic operation, is more convenient for management automation, remote control, hydraulic signal device, can be used for automation and centralized control.
Hydraulic device is made of hydraulic pressure valves to regulate the opening and closing or drive it by control, motivation and actuators are composed of three parts. Control part consists of a pressure control valve, flow control valves, directional control valves and electric control system composition. Drive by the motor or pneumatic motor, hydraulic pump, tank and so on, is the effective power on the electric or pneumatic motor axis into hydraulic transmission fluid pressure can. Actuator has two kinds, one kind is hydraulic cylinder actuators, realize reciprocating linear motion; The other is a hydraulic motor actuators, realize the rotary motion, the advantages and disadvantages of hydraulic device is as follows:
A, hydraulic valve device
1) the simple and compact structure, small volume;
2) is stable and reliable;
3) can get a lot of output torque;
4) the output torque can be accurately by constant pressure relief valve adjustment, including the opening and closing torque adjustment, even can be reflected directly by hydraulic pressure instrument;
5) easy speed regulation;
6) in power, the sudden accident, still can use accumulator to one or several power operation. The long distance pipeline emergency shut-off valve and wellhead discharge automatically
Valve has a special meaning.
Second, the hydraulic valve gear faults
1) the oil temperature is greatly influenced by environmental temperature, the oil temperature change caused by oil viscosity changes, affect the operation;
2) piping trouble, easy to produce leakage;
3) is not suitable for the signal to produce a variety of operations (such as signal amplification, memory, logic, arithmetic).