The solenoid valve is magnetically attracted by the electromagnetic coil to overcome the pressure of the spring to drive the spool, and the electromagnetic coil has a simple structure and a low price, and can only realize the switch;
The electric valve drives the valve stem through the motor to drive the spool, and the electric valve is divided into (shut-off valve) and regulating valve.
The shut-off valve is a two-position operation that is fully open and fully closed. The regulating valve is equipped with an electric valve positioner on the above, and the valve is dynamically stabilized in one position by closed loop adjustment.
The use of electric and solenoid valves:
Solenoid valve: Switch control for liquid and gas lines, is a two-DO control. Generally used for the control of small pipes.
Electric valve: Analog adjustment for pipe media flow in liquid, gas and wind systems, is AI control. In the control of large valves and wind systems, electric valves can also be used for two-position switch control.
Solenoid valve: It can only be used as a switch quantity. It is DO control and can only be used for small pipe control. It is common in DN50 and below pipes, and it is rare.
Electric valve: It can have AI feedback signal, which can be controlled by DO or AO. It is more common in large pipes and dampers.
1, switch form:
The solenoid valve is driven by the coil and can only be turned on or off. The switching time is short.
The drive of the electric valve is generally used for the motor. The opening or closing action requires a certain amount of time for the analog quantity, and can be adjusted.
2. Nature of work:
Solenoid valves generally have a small flow coefficient and a small difference in working pressure. For example, a general 25-caliber solenoid valve has a smaller flow coefficient than a 15-caliber electric ball valve. The solenoid valve is driven by a solenoid valve coil and is relatively susceptible to damage by voltage surges. Equivalent to the role of the switch, is the role of opening and closing.
The drive of the electric valve is generally a motor, which is more resistant to voltage shock. The solenoid valve is fast open and fast closed. It is generally used in small flow and small pressure, and the electric switch is required in the place where the switching frequency is large. The opening of the electric valve can be controlled. The state has open, closed, half open and half closed, which can control the flow of the medium in the pipeline and the solenoid valve can not meet this requirement.
Solenoid valves can be reset by general power failure. For such functions, electric valves require a reset device.
3. Applicable technology:
Solenoid valves are suitable for some special process requirements, such as leakage, special fluid media, etc., which are more expensive.
Electric valves are generally used for adjustment and also have a switching quantity, such as: fan coil end.