Changing solenoid valve from normally open to normally closed

The only answer is to take it apart carefully and try it out. With this sort of this you normally find it is either very easy or very difficult.

You have to think about what happens when the valve has no power. In your case when there is no power it is Normally Open. When you energise, something happens to close the valve. In the case of solenoids this typically means energising a magnetic field which then moves a coil to close the valve.

You would now have to do the opposite. So I would presume this means moving springs about to ensure the valve is closed when you have no power and then change magnetic polarity to make the valve open. As you are dealing with water or air pressure I would suspect that more engineering is involved to ensure that valve can actually stay closed without power etc.

Hi Avinash,

You can try plugging the top hole and opening the one that is currently capped. Keep in mind these valves have polarity and if you hook them up reversed they will bleed fluid past the valve once the pressure exceeds the compression strength of the internal spring.

John

You can wire the coil through the normally closed contacts of an additional normally closed relay.

ahhhhhh, be careful of what happens on power loss

Looking at the data sheet, you really can’t change this. It is set up as normally open and needs power to energize and become closed. Whenever power is lost, there is a spring that will shuttle the valve over to the opened position. You’d need to look up the manufacturer part number to get the opposite version part number.
Now with logic and a controller you can always invert the logic to get the function you want, but in the case of power loss it is fixed.