Solenoid Valves: Difference Between Normally Open & Normally Closed

November 28

As the title of this blog suggests, here we are gonna discuss the two major types of Solenoid valve. Mostly the solenoid valves come up in two conditions, either they are normally open or normally closed. If you are not aware of solenoid valves, kindly click here to read the full article about industrial solenoid valves. Whenever you choose any solenoid valve to utilize at your working line, it comes up in an idle condition. In that condition, either the valve allows the flow to pass out or prevents it. The normally open solenoid valve allows the flow in idle condition while the normally closed solenoid valve stops the flow.

Normally Open Solenoid Valves

Normally Open Solenoid Valves require energization to stop the flow. A 2-way solenoid valve has two ports called inlet and outlet, between these two ports a plunger set in an orifice. In idle condition, this plunger is set to the open position and allows the flow via orifice from the inlet port to the outlet port. When the solenoid valve energizes the plunger closes the orifice and prevents the flow from passing out from the outlet port.

The normally Open Solenoid Valve remains open until you energize the solenoid coil.”

Solenoid Valve


Normally open Solenoid Valves are a very useful and cost-saving device for applications, where the minimum stoppage is required. It saves energy because you have to energize it when it requires to operate, otherwise it allows the fluid to pass away in an idle condition.


Usage of a normally open solenoid valve for constant stoppage of fluid for a long period may increase the cost. You can’t use it at the end of the pipe as a shutoff valve.

Normally Closed Solenoid Valves

Normally Closed Solenoid valve works opposite of the normally open condition solenoid valve. In this valve, a plunger has been set to shut off the orifice and prevent the fluid to pass through. When the solenoid valve energizes the plunger opens the orifice and allows the flow to pass out.

The normally Closed Solenoid Valve remains close until you energize the solenoid coil.”


Normally Closed Solenoid valves are used where the constant stoppage is required. It requires energy when you need to allow the fluid from the valve. Therefore it can be used to set as an end closing valve.


Usage of a normally closed solenoid valve for the stoppage of fluid for a short period may increase the cost.


Here we discussed the major facts and the working phenomena of both kinds of solenoid valves. Both kinds of Valves are useful as per the user’s requirement. So, you have to decide which type of solenoid valve is suitable to fulfill your working requirements with cost-saving devices.