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Gas-Fired Steam without Electricity? (6 Posts)
Gas-Fired Steam without Electricity?After losing power for close to 20 hours, I started thinking about the different methods of heating and generators and inverters and all of that kind of stuff you think about when you're without power and have nothing to do except worry about frozen pipes.
My single-zone gas-fired boiler (with standing pilot) requires 120V to operate the gas valve, vent damper and circulator.
If I had a one-pipe gas-fired steam system (which I've had in the past), wouldn't it be possible to operate it without electricity in the event of a power outage? No circulator, no zone valves... What about the gas valves? Most typical gas-fired water heaters don't need electricity to operate their gas valves. Are these types of gas valves available for boilers? It sure would beat having to hook up a generator, or use a battery and inverter after doing all of the wiring modifications to get the circuit powered.
"Powerpile" systems used onmany steam boilers all over the Northeast have run no matter what happens to the grid. They use a pilot generator that puts out about 750 millivolts which is sufficient to operate the gas valve manufactured for that purpose
They are no longer on gas equipment since the mandate of 1979 for dual seated "redundant gas valves" in order to insure a safer operation the odds on two valves failing to close versus one valve. Powerpile valves could not operate with a dual valve set up so they are no longer allowed on heating equipment. We still see them on decorative appliances, unvented space heater's, pool heaters. The Amish still have access to powerpile in some areas. They were a great system. See my posting about my experience this weekend with the snow storm on the Wall.
What kind of gas valves do regular run-of-the-mill gas water heaters use? For safety, I'd imagine they'd have to have double-seated gas valves as well, and they don't use line voltage. If they don't have to use double-seated gas valves, why do boilers?
I'll be sure to take a look at that post of yours; It sure was one hell of a storm! National Grid wasn't too bad in getting the power back on here in Cranston, but I definitely think I'll be investing in a small generator next year at least to power the 3 boilers (mine being one of them) in my 3-family.
NickThis post was edited by an admin on February 10, 2013 3:15 PM.
Water heaters usea single seated set up with total regulation of gas pressure and incorporate an ECO (195° fusible link safety) which is a one time fail system. The valve is operated from a standing pilot system using a 30 millivolt thermocouple for the pilot safety system. The temperature is controlled by the rod and tube inserted into the water which is attached to a single seat mechanism. The ECO would typically be considered the safety versus a dual seat application.
so would it be possibleto setup a series valve arrangement (like we see on commercial gas trains) using two modern millivolt valves, with two pilot TCs separately heating?
When you say modernmillivolt valves what make and model are you talking about? It really is not feasible to do what you are asking. I have done old large gas actuated boilers with two safety pilots, retrofitted to a powerpile system with one pilot handling the generator (750 millivolts) and the other pilot using a cabinet mounted 30 millivolt pilot safety tied into the 750 millivolt valve. This insures that if any pilot system fails the complete boiler is shut off. That would not however cover the design requirements for redundancy today.