We aslo have them in stock.. THey are in our site
im was using a home depot well check valve that works up to 200 psi. yeah, it failed, adn almost took my york with it. i have one from a 18 wheeler store ready to go in now.
Hardware store stuff is not made for higher pressures, let alone DOT approved. Use the right stuff & you won't have problems!!
you can get one at your local NAPA for about 20 bucks
hey man, check out this site: McMaster.com (Check Valves Page)
I bought 2 of the Spring Loaded check valves (first on the page) and they work great. Usually you dont need them as large as 3/8" or 1/2" so this page has other size, and other threads.. so less $/time/hassle of adapting them to fit using nipples/couplings. Let me know if that helps at all.. give them a call, they got mine to me QUICK!
call em up 812-782-3581...i dont think their on the website yet...they have 3/8 and 1/2 for 22.99
The difference between the two are SMC is a diaphragm high flow check valve and the parker is a ball check valve.
i think either would do the trick but the big side to a ball check is it rarely every goes bad. diaphrams wear easier. but with the pressure you have, should be fine. parkers are rated for 2000psi, made of brass so it doesnt rust or break. same with the parker flow controls and mufflers and dot fittings we carry. all brass, plastic just doesnt hold up as well. dot approved or not