On Sun, 15 Feb 2009 22:40:50 -0800, "Bill Noble"
wrote:



there are no bellows - the handle presses on a stainless shaft, there is a
steel bushing that is not part of the valve body, through which the
stainless shaft passes (loose fit) - I didn't see any packing nor any way to
retain the packing. The internal pressure must open the valve, the handle
only presses it closed, nothing pulls it open.


It's not that outrageous. Thermostatic heating radiator valve bodies and
solenoid valve bodies frequently have a similar construction, except that they
have a return spring to close the valve.


Mark Rand
RTFM