Propane range safety ?

[PP]

After talking to a "certified LP tech", I am looking for a knowledgeable answer to this question. For 30+ years, I have been enlarging the orifice on the main stove top burner to generate more heat. The wife and I use our gas range all the time and we find we need a burner that gets hotter (french fries, donuts, you get the idea) than the factory setup. I have the same old hat pin that I've always used since our old schoolie back in the 70's to enlarge the jet orifice. I then slip the air regulator wide open and end up with a burner that will heat a kettle of water in minutes, not days. By opening the air up, I eliminate the yellow tips on the flame. The tech informed me that I am flirting with disaster. I disagree. Who's right?
Thanks for any informed opinions as well as others LOL, Will
PS- I know Cody must do this on every burner just to thaw out a kettle of water

[TomC]

Course the tech is going to tell you that to CYA.  Sounds like you've done it all along and know what you're doing-don't see a problem.  I would suggest you install an electric solenoid valve on the propane tank with the switch in the kitchen.  Then if anything happens, you can shut off the propane from inside.  I only have the stove and furnace running off propane, so I like to keep the gas off unless using it-which the solenoid works perfectly for.  Good Luck, TomC

[cody]

I don't know, I've never done it but you can buy them in different sizes for more BTU's, main thing if your going to adjust it yourself is to make sure the flame is blue, sounds like you've got the orifice and air adjusted pretty much right.

[eddiepotts]

I don't know anything about the orifice but I would like to know about cooking in your coach. Just the thought of the grease on the walls and floor keeps me from installing a range. Do you have any problems with that. This may need a new thread but I am really just asking PP about this. It just seems like a small area to be deep frying french frys or anything with boiling grease.

[PP]

TomC, I like that idea, but I'm not sure where to plumb it in. We have a 35G built in tank, a 10G portable bottle, and a valve for connecting to an external source when available (Hosting in CG's). I'll need to install it after all the LP sources and before the appliances. Right now that is only the range and the Cat heaters, but I plan to install instant Hot water within the next year also. Adding the solenoid will definitely be in that project if not before. Thanks, Will
PS-just got your reply Cody. That's what started me questioning my actions in the first place. A friend was complaining about his low flames and inquired at an LP business about larger jets and they informed him that such things weren't available for stove tops. He then went to an RV outlet and they claimed they'd never heard of anything like that. But they would be glad to come out and check his propane system for a nominal fee. I don't want the liability of modifying someone elses stove if it's not kosher, and no, I don't charge,

[rv_safetyman]

Tom, what solenoid valve do you use?

There was a great system made by CCI (7719) where the detector would shut off the propane if a leak was detected.  I always recommended that system be added when someone installed my fire suppression system.  I simply wired a NC relay in the wiring to the solenoid valve and if my system detected a fire it opened up the wiring to the valve.  Unfortunately, CCI went out of business.  Their valve appeared to be a standard unit, but 9V.

I often wonder if there is a special requirement for a propane solenoid valve.  Never can find the time to do any research on the subject.

Jim

[PP]

Eddie, we keep a kettle of oil on hand in an old pressure cooker (lid seals tight so we don't have to worry about spillage on the road) just for deep frying. There is a skylight in the kitchen that we open and a vent directly over the stove that we run. The screen on the vent needs cleaning periodically, but not all that often and my wife is a clean freak. The range is cleaned almost daily after doing the dishes and surprisingly, there isn't much more to it. We have a lot of natural wood in the kitchen that we oil at least once a year because we maintain 40%  humidity or less in the coach and it dries out with time (walnut). Boiling water for pasta creates much more of a problem than deep frying   Will

[Sean]

Interesting you should ask, as we just had a long discussion about LP ranges on the other board, and I did a little discourse on stoichiometry over there.  The thread is here:
http://www.busnut.com/bbs/messages/11/43139.html

The short answer to your question is, yes, you might be flirting with disaster.  There are two reasons.  One is that by modifying the LP orifice, you are changing the air/fuel ratio, and if that results in non-stoichiometric reagent quantities, you will get harmful products-of-combustion including carbon monoxide.  Tell-tale indicators of improper mixture include any yellow at all in the flame, and/or molecular carbon (soot) accumulating on the burner, cookware, etc.

Opening the air admitter can help to bring the mix back into stoichiometric proportion, but only to a point.  That's because there is an element of fluid dynamics involved:  the designer of the burner assembly has allowed for a certain air amount to be drawn into the burner through venturi action, and above certain flow rate you will disrupt the laminar flow and not be able to draw in enough air.  In short, unless you have the background in fluid dynamics and a good understanding of burner jet design, you could very easily create a situation wherein a stochiometric mixture of reagents is no longer possible.  While non-blue flame and soot are possible warnings, it IS possible to be creating carbon monoxide (CO) gas without either of those symptoms.  CO is colorless, odorless, and deadly, and does not generate symptoms of breathing difficulty as does, for example, carbon dioxide (CO₂).

The second reason is that all the burner components have been designed for a certain maximum temperature as dictated by the burner's rated BTU/hr rate.  It is quite possible that parts of the burner can be damaged, even melt, if you significantly increase burner output.  In addition to leading to non-stoichiometric combustion as described above, this can actually result in an explosion as quantities of unburned LP might be allowed to accumulate in parts of the burner.

Of course, it is possible to do this without any adverse results, so long as neither of the above situations is reached.  But you are putting a lot at risk that you will not exceed either of the limits by making a modification like this without benefit of engineering analysis.  To put it another way, I am an engineer and I routinely modify things to bend them to my will, but I would never modify a gas-burning appliance beyond the limits established by the manufacturer.  Too much risk for my blood.

No need in this case, anyway.  LP burners are available in almost any heat output, all the way to 50,000 BTU/hr.  If that's what you need, my recommendation would be to buy one that is designed and built for the purpose.

Do remember that burning LP indoors, even when at ideal stoichiometric mixture, uses up fresh air at a prodigious rate, and produces CO₂ and water vapor.  The bigger the burner, the more fresh air exchange you will need.  I discussed the quantity ratios in the thread I linked above.

FWIW.

-Sean
http://OurOdyssey.BlogSpot.com

[cody]

Wow, an expert in fluid dynamics now too, sean is my hero.  I have a small parts bin with orifices of different sizes for stoves and heaters, the main thing is to get the air to gas ratio right, a blue flame is your first indicator of proper settings or at least close.  I trust it's still ok to profess admiration for anothers life achievements here.

[kyle4501]

I design & build gas burning machines for the manufacturing industry. We use burners ranging from 29,000 BTU/hr to over 2,500,000 BTU/hr.

You can't always go by the color of the flame, often there are impurities in the combustion air or the gas itself that will burn yellow regardless of ideal stoichiometric ratios. We have used gas & air mass flow meters to ensure the perfect air fuel ratio & still get yellow in the flame.

Enlarging the gas orifice for a home appliance is very different than changing the one in your coach. Your home appliance doesn't change altitude, your coach does, so if you have maxed out the air supply, you can find yourself in a situation where it can't get enough air for max fire.

Propane is heavily regulated & as a result, it is safely used by almost everyone. So safe that some will disregard the inherent dangers & make risky choices.

All that said, I do believe you can 'safely' enlarge the gas orifice to increase the burner output. I also KNOW that by doing that, you will be reducing the safety factors the engineers built into the system. How far the capacity can be safely increased is not something I'm willing to speculate on, so I will purchase a correctly sized burner & save my exceeding the published ratings for the engine & drive train. . . .  

[TomC]

Now don't laugh to hard-I bought my propane solenoid valve from Camping World-designed and sold as such.  Good Luck, TomC

[brando4905]

PP,

It's hard to beat deep fried donuts made from a can of biscuits!!

Brandon

[PP]

PP,

It's hard to beat deep fried donuts made from a can of biscuits!!

Brandon

A man after my own heart