My sister has propane at her house. The propane company shut off the tank
because they said they tested the line and found evidence of a leak
(without knowing where the leak is). My sis called a couple of plumbers
and asked for quotes to work on the line. A couple of them told her they
didn't work on propane lines.

Any idea why they wouldn't? What's the difference between a propane line
and a regular natural gas line that they wouldn't do the work?

--
charles