residual magnetism in the coil is quite possible, as well as the valve body if it is a steel body. They do offer almost eery valve in brass and some in stainless as well.

If it is a 2" valve with a really large C.V. the maximum pressure on the valve might be lower than the 40 psi you are using. Try running it at 20 psi or 10 psi just for kicks and to eliminate the pressure theory.

You might try swapping coils as well.

Also, make sure that what you have is an AC valve. not only do they make AC and DC coil packs in a range of voltages, but the innards of the valve assemblies differ as well. You cannot just put a DC coil pack on a valve designed to take an AC coil. Nor will the opposite work properly. The coils will FIT, but the actuators are designed specifically for each's respective fields.

Results of 1 hour with tech support on ASCO valve problem:

I talked to the tech for a while and he actually talked me through a full dismantling of the valve and actuator assemble. I will try to talk in visual phonetics as I describe what I did. I took off the green coil and then using a fairly large wrench I unbolted the long polished silver rod that comes out of this valve (the rod that the coil slid on). After opening it I found that inside that rod there is a piece of metal that slides inside the silver rod and when the valve is energized (Open) it is pulled up the silver rod away from a seat and allows air to enter a chamber that actuates the valve. When the valve is de-energized a small spring pushed the piece of metal in the silver rod is pushed back over the seat thus stopping the airflow and closing the valve. Apparently at some point in the past, the valve was open and someone took out that spring. That is what led to the symptoms I had. The valve would always open but would not close as de-energizing it wold just let the metal rod rest in the open position. Why would removing the energized coil cause it to shut? Magnets have a field that is stronger in some places than others. As I would pull off the coil, the magnetic field was moved to a point where it would act on the piece of metal inside the silver rod pushing it to the closed position. When I put the energized coil back on it would function as usual.

Make sense? I was thinking about doing a youtube video on this as it is so hard to describe. They wanted $265 for a rebuild kit that contained the spring but that is out of my budget. Against their advice I built my own spring out of a pen and the valve seems to work great so I know that was the problem. Anyone have the hook up on the correct spring? Let me know if you have any more questions and thanks for the ideas.

If anyone out there is real experienced with standard 20 lb accumulators, 1/2 inch and 3/4 inch discharges I am looking for some one to shoot some ideas off of. It would save me a bunch of testing.

Thanks! - Greg