The difference between solenoid valve normally open and normally closed

The working principle of the solenoid valve normally open solenoid valve is: energize the coil and connect the air circuit. Once the coil is de-energized, the air circuit will be disconnected, which is equivalent to "jogging". The principle of the principality of the normally closed solenoid valve is to energize the coil and the air circuit is disconnected. Once the coil is powered off, the air circuit will be connected, which is also "jogging".

  It is usually selected according to the length of continuous working time: normally closed, normally open, or continuously energized. When the high temperature solenoid valve needs to be opened for a long time, and the duration of excess time to close, the normally open type should be selected. When the opening time is short or the opening and closing time is not long, the normally closed type is selected. However, for some working conditions used for safety protection, such as furnace and kiln flame monitoring, the normally open type cannot be selected, and the long-term power-on type should be selected.

  The solenoid valve mainly uses electricity as an energy source. The current generates electromagnetic force by driving the electromagnetic coil, and then the electromagnetic force controls the valve by controlling the spring magnetic tilting liquid level gauge. Of course, this spring can be used to control the closing of the valve or to control the opening of the valve. So according to this feature, we can either make the air circuit break when the coil is not energized, which is a normally closed valve, or make the air circuit open when the coil is not energized, which is a normally open valve.

  The working principle of the normally open solenoid valve is: the coil is energized and the gas circuit is connected. Once the coil is de-energized, the gas circuit will be disconnected, which is equivalent to "jogging". The principle of the principality of the normally closed solenoid valve is to energize the coil and disconnect the air circuit. Once the coil is powered off, the air circuit will be connected through the electric actuator, which is also "jogging".

  It is usually selected according to the length of continuous working time: normally closed, normally open, or continuously energized; when the solenoid valve needs to be opened for a long time, and the continuous time is excessive, the normally open type should be selected. If the opening time is short or the opening and closing time is not long, choose the normally closed type. However, for some working conditions used for safety protection, such as furnace and kiln flame monitoring, the normally open type cannot be selected, and the long-term power-on type should be selected.