quick and dumb OBA question- pressure relief valves

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

Oct 19, 2004
I just ordered some parts to complete my On Board Air set up. I got a new tank and a pressure relief valve. Both are made by viair. The place I ordered from only had 175# valves, while the tank is a 150# tank. I am thinking of calling them back to cancel the relief valve order, and I'll get one from someplace else even though the guy on the phone said it would be fine to use that valve with the tank. What do you think? Is a 175# relief valve okay to use with a 150# tank?

You might as well just plug the hole where you would insert the relief valve and save yourself some money. Just don't be too close when the tanl blows up.
I will find a lower rated relief valve. But mostly because of my gauge- which only goes to 160#. My cut off switch is at 145#.

I have heard different things about air tanks. 1- they dont blow like a stick of dynamite. They peel or crack, slowly, usually at a bung or seam- so you'll hear it releasing air- prob as much or more than a relief valve.
I also read they are rated at 1/2 to 1/3 or so their max rated pressure. So a 150# tank could hold 450# before blowing.
I am actually not super concerned that at 160# or 175# the tank is gonna bust. But more so that it would fatigue the tank and everything else around it like gauges and my York. It is more pressure than the 160# gauge is rated at.

2 things-

Get a mini adjustable pressure relief valve from mcmaster.com. I have used these on half a dozen OBA apps and they work great. Huge adjustability range.

Run a check valve on the york. You won't damage the york without one, but you will leak back through it. mcmaster also stocks an inexpensive one that is very small and works great.
update. I got my checkvalve and adjustable pop valve from mc master earlier this week ( speedy delivery). Got the viair tank today, and their instructions reccommend the 175# popvalve they sell in their kits. oh well. I needed a check valve anyway, and my gauge only goes to 160#..

thanks guys-

Users who are viewing this thread

Top Bottom