Fuel Gas Safety Manometer

[fredrosse]

Installed new gas burners into the Margaret S, and wanted a manometer to measure the fuel gas pressure to the burners. Typical gas pressure for aspirating burners is 11 inches Water Column (In WC). The burners here run OK with gas pressures ranging from 2 in WC up to 12 in WC, so I can adjust the burner output according to how much steam is needed to run the engine.

An ordinary “U-Tube” type of manometer could have been used, but the device pictured has safety features that are worthwhile. If the gas pressure is accidentally turned on too high, the manometer water seal will be blown out, and gas will issue from the manometer atmospheric pressure vent. Since Propane is a heavy gas, it would accumulate low in the boat if there are leaks, a safety concern. Therefore the manometer outlet is directed overboard.

If the manometer water is blown out by excessive gas pressure, this manometer automatically resets itself without having to refill the clear manometer tube. There are two water reservoirs, or "Pots", each having a water surface area that is several times the area of the clear indicating tube. Normal gas pressure is connected to the lower Pot, and drives the water column up the clear tube to measure gas pressure. But if there is excessive gas pressure all the water in the lower chamber is blown into the top chamber, then any passing gas is vented overboard. When gas pressure is reduced by the operator, the water in the upper chamber can flow by gravity back down to the lower chamber, and the manometer function is restored without having to refill anything.

[steamdon-jr]

Fred, good seeing you this past weekend at the Lake Nockamixon steamboat meet. I am always amazed at the stuff you do, you always seem to be one step above others with your builds and everything is very well thought out.

See you in July

[fredrosse]

Thanks for the compliment Don, and we hope to see your new boat on the lake soon!

Well, I have been totally taken with STEAM since about 1951, and have been paid in full time jobs to design STEAM power stuff for very nearly 47 years. I guess that qualifies me for some level of knowledge. Most if the stuff I come up with is nothing new, several things I think I invent, then later find the same thing in a 19th century Sientific American, or one of several other publications.