Propane overfill by a "professional"

How did the fellow know to shut off the flow at 7.6 gals?

Spitter valve.

I don't get it. After the first time he filled it incorrect, I'd never go back. Final! That's it! Why did you keep going back? Why not complain to his manager? But why blindly let him keep doing it?

Hardly blind, my friend! Frankly, he's never managed to get quite so much propane into these tanks before. 7.0, 7.1, a little over but not enough to be scary. "Only one last straw", like I said.

What I'd do is put that tank in service NOW, use it to heat water and the RV while you are packing to move, by the time you are on the road you should be good.

Aye, it's been running the furnace, keeping the rig defrosted until we're ready to roll. It's well below 80% now.

NOTE: there is an alternate method for telling when a portable tank is full that works well. SCALE THE THING.

Hmm. I've always bought propane by volume, never by weight. They just don't do it that way out here in the west -- I gather that it's more common back east. Here, most stations don't even have a scale. I've only seen one exception, and that was a rusty old beam scale made in the 1930s. A nice collector's piece, really.

It's a good thing you put professional in quotes. I attended a formal course by the state of FL for dispensing propane but didn't have to. Most places you only need one certified person for every 8 or 10 dispensers. The non-certified folks usually get a 5 minute briefing on how to do it, then they're turned loose on live customers.

When I was a kid, I worked at a gas station that also sold propane. My total training was the owner doing a show-and-tell with me a couple of times, and then I was a genuine propane pumpin' professional! At least I had the brains to say "I don't know how to fill this" when someone brought me a weird-looking tank I'd never seen before. (Which I now recognize as a liquid-service forklift cylinder, but at the time....)

So the question came up once already. Did he charge you for more propane than was supposed to be put in the tank?

As noted, it's sold by volume here. Paid for what I got, got what I paid for, and made good use of it.