Well, I actually took the tank to the gas dealer I spoke with, the one who
told me that the RV guy did it wrong.  Now he tells me that the RV people
did it right, and that's what he would do if he were doing it with a small
tank.

So, I called another gas distributor.  Same answer, with more detail, that
that is the correct procedure for a small tank, that only large tanks need
the vacuum procedure.

I'm going to contact Manchester Tank.

mcneely