How to select the valve according to the nature of the valve drive
1 power driven valve
Power driven vacuum valve is common drive valve, usually referred to as the form of the drive device for the valve electric device.
The features of valve electric device are as follows:
1) open and close rapidly, can greatly shorten the time required to open and close the valve;
2), can greatly reduce the labor intensity of operators, especially for high pressure, large diameter valve;
3) suitable for mounting in a position that can not be manually operated or difficult to access, easy to implement remote control, and the installation height is not restricted;
4) is conducive to the automation of the whole system;
5) power supply is easier to obtain than gas source and liquid source, and the laying and maintenance of the wire is much simpler than that of compressed air and hydraulic pipeline.
Valve electric device is the disadvantage of complex structure, the use is more difficult in humid places, when used in explosive media, the need for flameproof measures.Valve electric device driven by different types of valves can be divided into Z type and Q type two categories. Z type valve electric device output shaft can turn out a lot of laps, suitable for driving gate valve, globe valve, diaphragm valve, etc., Q valve electric device output shaft can only rotate 90. Suitable for driving plug valves, ball valves and butterfly valves. According to the type of protection, there are a common type, flameproof type, heat resistant and three in one type.Valve electric device generally by the transmission mechanism (reducer), motor, stroke control mechanism, torque limiting mechanism, manual - electric switching mechanism, the opening indicator, etc..
2 pneumatic and hydraulic valves
Pneumatic vacuum valve and hydraulic pressure based on a certain air, water or oil as the power source, using the cylinder and the movement of the piston to drive the valve, the general pneumatic air pressure is less than 0.8MPa, the hydraulic or hydraulic pressure is 2.5MPa~25MPa. Sanitary diaphragm valve; rotary gas and liquid driving device is used to drive the ball valve, butterfly valve or cock valve. The driving force of the hydraulic device is large, which is suitable for driving large diameter valves. If used to drive the plug valve, ball valve and butterfly valve, the piston must be converted to the reciprocating movement of the rotary surface. In addition to the cylinder to drive the piston, there is no use of pneumatic film drive, because its travel and driving force is small, it is mainly used for sanitary regulating valve.
3 manual valve
Manual vacuum valve is the most basic way of driving the valve. The utility model comprises a hand wheel, a handle or a hand plate which are directly driven and driven by a transmission mechanism to realize two kinds. When the starting torque of the valve is larger, the utility model can be driven by a gear or a worm gear to achieve the purpose of omission. Gear reduction ratio is small, suitable for gate valves and globe valves, worm gear reducer is relatively large, suitable for cock flash, ball valve and butterfly valve.