When we brought our "new to us" two year old 5th wheel home from the dealer I noticed the smell propane very strong. Upon inspection of the two 30lb cylinders I noticed one was venting propane uncontrollably. I had the valve shut off. The dealer had topped both tanks before we left as part of the deal. Now what should I do? After a moment or two of panic, I disconnected the tank and carried it 100yds into an open hay field behind my house and just let it set there. Eventually it stopped venting and I brought it back near the house. I called the dealer on Monday morning and he said the OPD valve must have been defective allowing the tank to be overfilled !!!! He instructed me to return the tank in exchange for a new one. Now here is the problem I have with this. If the OPD valve can be "defective" who's to say this cannot happen to anyone anywhere? I don't trust the OPD to make the determination of how much it will hold. I fill my tanks to less than full always. Have the tanks weighed and determine how many gallons will take it to 3/4 full.