At 04:34 PM 10/18/2002, Stan Wilder wrote:
>All high pressure cylinders have a double seat valve.
>In other words they must be fully closed or fully open, in either of
>these positions they seat against a seal and should not leak.

Stan, the pressure in these tanks is closer to an acetylene tank  (250 psi)
than an oxygen or other high-pressure tank (2000+ psi).  I'd be happy to
hear that the LP-tank delivery valve is a double-seat type, but I don't
think you can take it as a given just from the pressure.

>The slight leaking in the mid range of the valve is caused by excessive
>pressure and is normal.

Strikes me that a leak you can actually hear is a bit beyond "slight" -- my
welding tanks don't make any noise while shifting the valve, and they're
running at ten times the pressure.  However as you say, if it stops when
the valve is fully open it's perhaps not a big deal.  I'm still not happy
about it though -- the propane stink tends to cling and might obscure a
"real" leak from the regulator etc.

david

--
David Beierl - Providence, RI
  http://pws.prserv.net/synergy/Vanagon/
'84 Westy "Dutiful Passage"
'85 GL "Poor Relation"