On a related note, somehow over the winter the main on/off 'tap'
thingy got broken off.  No idea how.  I only noticed it after the
propane dude filled my tank so it appears to be open and everything
working fine.  No leaks as far as I can tell (did the soapy water
test).  Can someone tell me what this 'tap' is actually called, and
can I replace it without replacing the entire tank?  I've done that
once already.

Thanks
Jeff
85 Westfalia GL