Originally Posted by gypsmjim
That's what I thought. I don't see any check valves in the ones I just bought.
If you open the tank valve with nothing attached, nothing comes out. But the old style tanks (that were outlawed 12 years ago) would empty completely if you opened the valve. That's why I thought the check valves must be on the tank.
There is a high flow shut off valve in the tank. The pigtails, the ones with the big green knob anyway, have them also. These tanks will still accept the older screw in connectors with left hand threads. Is this what you have? If so I doubt they have the shut off valves in them, but I don't know about that. I didn't even know you could still buy these old style, but I just don't know.
2006 GMC 2500HD CCSB 4x4 Duramax/Allison, Titan 52 gallon fuel tank, Prodigy Controller, B&W Companion Hitch
2010 Jayco Designer 35RLTS, Cummins/Onan RV QG 5500 EVAP, Progressive Industries EMS-PT50C, TST Systems 507 TPMS, RV Flex Armor Roof