The difference between electric valve and solenoid valve

1. Differences in working principles
1. Solenoid valve: The solenoid valve is composed of an electromagnetic coil (electromagnet), a valve core and a valve body. When the electromagnetic coil is powered on or off, it drives the valve core to move, allowing the fluid to pass through the valve body or be cut off.
2. Electric valve: The electric valve drives the valve stem through a motor to drive the valve core to pass or cut off the fluid.

2. Differences in valve types
1. Solenoid valve:
1) Two-way solenoid valve: The valve body has an inlet and an outlet connected to the pipeline. There are two control methods: normally open type (the solenoid valve is closed when energized, and the fluid is cut off), and normally closed type (the solenoid valve is opened when energized, and the fluid is cut off). through the valve).
2) Three-way solenoid valve: The three ports of the valve body are connected to the pipeline and have two holes. It can be used in three control modes: Normally closed type (the pressure port is closed when the power is off, the exhaust port is connected to the cylinder port, and the power is on When the valve is powered on, the pressure port is connected to the cylinder port and the exhaust port is closed), normally open type (when the valve is powered off, the pressure port is connected to the cylinder port and the exhaust port is closed;when the valve is powered on, the pressure port is closed and the cylinder port is connected to the exhaust port) port), universal type (allows the valve to be connected in one of the normally closed or normally open positions).
3) Four-way solenoid valve: Generally used to operate a double-acting cylinder, with four or five pipeline connection ports, one pressure port, two cylinder ports and one or two exhaust (oil) ports.



2. Electric valve:
1) Electric valve with valve body and electric quarter-turn actuator: the electric actuator rotates the angle of the valve plate to control and adjust the valve shut-off and control the flow of the pipeline. The rotation of the output shaft of the electric actuator is less than one revolution, that is, less than 360 degrees. degree, usually 90 degrees to achieve control of the opening and closing process of the valve. Such electric valves are mainly butterfly valves, ball valves, plug valves, etc.
2) For electric valves where the valve body is matched with a multi-turn electric actuator (rotation angle >360 degrees), the rotation of the output shaft of the multi-turn electric actuator is greater than one cycle, that is, greater than 360 degrees. Generally, multiple turns are required to complete the opening and closing process of the valve. control. Such electric valves are mainly gate valves, globe valves, etc.
3) Electric valves whose valve body is matched with a straight-stroke electric actuator (linear motion): the movement of the output shaft of the electric actuator in the driving part is linear motion, not rotational. The opening and closing control is achieved by lifting and lowering the valve plate. . This type of electric valves are mainly regulating valves, single-seat regulating valves, double-seat regulating valves, etc.



3. Differences in control methods
1. Solenoid valve: driven by a coil, it can only open or close.
2. Electric valve: It is driven by a motor. The opening or closing action takes longer to complete than the solenoid valve. The flow can be adjusted by inputting current and voltage signals to the actuator. The general control signal is: current signal (4—— 20mA, 0——10mA) or voltage signal (0——5V, 1——5V).

4. Differences in application scope
1. The solenoid valve is driven by an electromagnetic coil. The driving force is small and it is relatively easy to be damaged by voltage shock. It is generally suitable for pipelines with diameters smaller than DN50 and below. The action time during switching is short, and there are special high-frequency solenoid valves, which are especially suitable for pipes with diameters smaller than DN50 and below. Used for pipelines with high operating frequency or short switching time.
2. The electric valve is generally driven by a motor, which is relatively resistant to voltage shocks and has large driving force. It can control large-diameter valves, and the electric valve can adjust the flow of the pipeline. It is especially suitable for large-diameter pipelines or requirements for pipeline flow. Use in places where adjustments are needed.
3. The solenoid valve can generally be reset when the power is cut off. To reset the electric valve, an additional reset device is required.
4. The solenoid valve is suitable for a wide range of media. Acid, alkali, water, gas, oil, steam and other media can be used. However, there are high requirements for the viscosity and cleanliness of the medium. Before installing the solenoid valve, add Install a filter to ensure the normal operation of the solenoid valve, with low leakage rate and high safety.
5. Electric valves are not only suitable for controlling general fluid media, but are especially suitable for controlling pulp, sewage, media containing fibers and tiny solid particles. The cleanliness of the media is not required, and the leakage rate is higher than that of solenoid valves.