Flammable gas in hydronic heating system

Mitch_4

The gent was using well water, and Nat gas seeped into the H2O.

I got the call because his relief valve popped, and the gas in the water lit off, and melted the overflow (plastic ) pipe.

Took a bi of anayzing from the experts to find that one..Only case like that I had, never heard of another.

Is he on well water?

dean olsen

flammable gas in hydronic heating system

I am searching for some information regarding the build up of flammable gasses in a hydronic heating system. I have a customer that must vent alot of gas from his system, for some reason he decided to see if it would ignite, which it did. The gas was analysed and shown to contain a considerable amount of light hydrocarbons and hydrogen (57.43%). Also the sample contains a significant amount of carbon monoxide (8.6%). The system is charged with 12% Inhibited ethylene glycol and with a molybdate based corrosion inhibitor. Any information will be appreciated. Thank-you
Dean Olsen

Ragu

Dean

I seem to remember an issue of the RPA newsletter from around 1998, and there was a technical article about venting hydrogen gas from a hydronic system.

dann crist_2

flame on !!

I cannot tell you the reason for the flamable gas but I did have an experience many years ago with it. I had drained the system down to do some piping changes at the boiler (boiler was located above all piping going to several hanging unit heaters) after sweating apart one of the fittings, the open pipe continued to flame for almost one full minute !!????

dann crist_2

PS

PS this system had no chemicals in the fluid--ie antifreeze etc.

FERGUS SMITH

GAS IN SYSTEM

THE PROBLEM IS A WATER GAS REACTION. IF A CARBON SOURCE IS HEATED RED HOT ALONG WITH WATER (STEAM), THE WATER AND CARBON REACT PRODUCING HYDROGEN AND CARBON MONOXIDE. IT SOUNDS LIKE SOOT/COMBUSTION GAS IS SOMEHOW COMING INTO CONTACT WITH STEAM IN THE BOILER. IT WON'T TAKE MUCH TO PRODUCE A LOT OF GAS.

FERGUS SMITH

GAS IN SYSTEM

IT'S ALSO POSSIBLE THE ETHYLENE GLYCOL IS REACTING WITH THE WATER IF THE BOILER HAS A HOT SPOT. BEYOND THAT, HYDROGEN COULD BE PRODUCED BY ELECTROLYSIS. IS THERE A HOT WATER HEATER WITH A BAD ELEMENT, A STRAY CURRENT, OR DISSIMILAR METALS IN SERIESFORMING A CLOSED CIRCUIT? ELECTROLYSIS, HOWEVER, DOES NOT EXPLAIN THE CARBON MONOXIDE.

Larry Weingarten

Heat source?

Hello: If your heat source is a tank-type water heater, hydrogen gas will be produced by the action of the anode in the tank. Of course that doesn't explain the CO.

It does seem ignition of this "system gas" is not really a concern unless it builds up and is released all at once in the presence of a flame or spark. Because of the CO, is there a way to vent it away from the living space?

Yours, Larry