"A tank filled on a cool morning to 80%.. Well by the time it sat in the hot afternoon sun for a few hours. that valve was venting propane. "
You may have a point there. It was cold as a lawyere's heart the morning I had it filled and the last few days have been warmer by several degrees. Checked it a half hour or so ago and no strong odor, and it is cooler now. I did smell a very slight odor but then the air is stirring a bit this PM, especially in the RV shed that acts like a tunnel running west/east