I got the solenoid thing bassackwards! I misread the article. According to an engineer on another forum that is a distributor for Asco solenoids in Oklahoma, I want a solenoid that is N.O. (Normally open) but when it's plugged in it closes. Then when the power goes out it releases oxygen by opening.

Indeed the following paragraph says just that:


Good Morning Cecil,
Just to be clear, solenoid valves are specified ... "what condition will the valve be with NO power to the coil".
So a normally open valve will be OPEN when the coil is NOT energized, closed with the coil energized.
If I understand your plan correctly, you want the valve to open with a loss of power to allow flow of oxygen into the fish tank....?
So you need a N.O. valve.........mh



Emergency Oxygen

For a quick response to a power outage, one option is to have several high-pressure cylinders of oxygen that are connected to an inexpensive normally open oxygen-rated solenoid valve that is simply plugged into a wall outlet. When there is power, the sole- noid is energized and closed. When the power goes out, the sole- noid opens and oxygen flows. A simple oxygen manifold then directs oxygen to an oxygen diffuser in each aquaculture tank. This type of emergency oxygen system can be set up for about U.S. $250.

http://pdf.gaalliance.org/pdf/GAA-Ebeling-March10.pdf

Last edited by Cecil Baird1; 09/21/15 09:43 AM.
If pigs could fly bacon would be harder to come by and there would be a lot of damaged trees.