There is a high flow shut off in the pigtails from the tank to the regulator also. I had both of mine fail a couple of years ago. So even if you have a full tank, open it slowly, you can still not get propane flow.
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