whynotfab
+1y
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!