[ayeckley]

Originally Posted by Peter Matteson

I was thinking more along the lines of http://www.grainger.com/Grainger/items/6D915?Pid=search

It's smaller and lighter than what you were looking at.

Specific to that relief, I wonder if by "adjustable" they mean "discrete" settings. I've seen some that are adjustable only by means of changing the springs, and others where the springs establish the range of adjustment. The knurled part suggests there is a fine-tuning aspect, which is what most teams will need. Assuming it is, that part seems to be the best option so far.

Originally Posted by Peter Matteson

I'm not sure about the back pressure regulator's legality or if you would want to use it. The p/n you list will constanly bleed air keeping your compressor running constantly. I would just use a second regulator and adjust the pressure down.

That's not how I read the spec for that particular valve, although I agree that the typical backpressure relief valve is designed to operate with constant flow-through rather than shutoff. So, as-written it shouldn't bleed until the upstream side (the backpressure side) exceeds the set pressure (which would be somewhere between 60psi and the rated pressure for the solenoid valve we are trying to protect). I suspect that in reality this BPCV doesn't have shutoff capability, and that your statement effectively correct.