--Coles used to sell a pressurized diaphragm valve for a fuel
system, set up so that if pressure fell in the boiler it automatically
shut off the fuel supply. What more does one need?

--
"Steamboat Ed" Haas : Heartily sick of
Hacking the Trailing Edge! : "oldies" stations!
http://www.nmpproducts.com/intro.htm
---Decks a-wash in a sea of words---