Probably more involved than that, but I am note sure of how CNG stove safety systems are set up…
the big issue, as you are probably aware, is that propane is heavier than air (and CNG is lighter than air). What this means is that a propane leak will result in propane settling low in the hull. Any ignition source will then cause an explosion.
CNG, on the other hand is lighter than air, so theoretically will drift up and out of the boat….so it is inherently way more safe.
To mitigate the dangers with propane, the propane tank must be housed in a locker of some sort outside of the cabin, and it must be vented out the bottom, so any propane leak in the locker would “drain” out to the atmosphere.
Another safety feature is a solenoid, that opens a valve in the propane locker to.et the gas flow only when a switch in the cabin is flipped to “on”. The idea is that when not in use, the propane is contained in the vented locker, and that reduces the chance of a propane leak in the piping. You could just open and lose the tank valve, but I guess the regulations assume we are all too lazy to open and close the valve.
On a non-safety issue, I assume that the orifice also needs to be changed on the appliance.
My old stove doesn’t use a thermocouple….. turn on the valve and light the burner. My oven does include a pilot light and a thermocouple. I light the pilot, and once the thermocouple gets hot, it will open the gas valve for the oven. We need the pilot light because the oven burner must be able to cycle on and off. And then light again when needed. Of course, once I am done using the oven, I turn the solenoid switch to OFF, and that kills the pilot light. Nso I need to relight it every time I use the oven.
Newer stove/ovens may have auto-ignition…mine 36+ year old boat is pretty basic. I keep a butane match next to the stove to light the burners or oven Pilot.
Too bad CNG isnt as available as propane…certainly a safer alternative. But if you can’t get it, it doesn’t do much good.
Greg
