Switching to Propane from CNG

[Stu Jackson]

Originally Posted by awaywego

I just talked with him on the phone and he has no idea what I was talking about...said he doesn't have anything to do with appliances.....?

Sorry, I thought he'd know.

Then try your hardware store as suggested, or do a Google search. This is such a recurring issue as to not be funny.

[newhaul]

Check with your local Johnstone supply they will be able to get the parts you need . You may need to take one of the old jets into them

[tinkrman69]

the thermostat is a valve and will work with any gas, just like the valves of the burners. the guy at the store may be know his stuff, but the thought of liability is inherent in his thinking and will only lead you to buying not modifying.

do the research and learn or spend the money and buy another stove. either way the responsibility is yours, weather you can sue someone or not.

search the web and cross reference the sites you find. read them through and learn, then take what you learn and rephrase your search words as you gain knowledge. The more knowledge you get the more freedom you'll get.

[newhaul]

Originally Posted by tinkrman69

the thermostat is a valve and will work with any gas, just like the valves of the burners. the guy at the store may be know his stuff, but the thought of liability is inherent in his thinking and will only lead you to buying not modifying.

do the research and learn or spend the money and buy another stove. either way the responsibility is yours, weather you can sue someone or not.

search the web and cross reference the sites you find. read them through and learn, then take what you learn and rephrase your search words as you gain knowledge. The more knowledge you get the more freedom you'll get.

I'm sure the op is capable,e of unscrewing the CNG oriface and screwing in the propane one as well as changing the regulator on the tank end. The cost should be well under 50 USD .
Just one thing that I saw incorrect here you can not drill CNG out for propane its the other way around propane or I faces are about half the size of cng ones.

[Paul54]

I converted my older 1984 CNG system to propane. The burner and oven jets will be smaller in diameter for propane than they are for CNG. I bought some off of ebay I think, very cheap and easy to do. Do a google search on conversions and you will be able to find a close match for the jet size you need. I re-jetted my burners, and used the same line from the stern locker to the stove.

Very IMPORTANT!!!, you will need to make or buy a propane locker for your LPG tank. The locker will allow any gas leaks to "flow" out and overboard, instead of collecting inside your boat. I would also recommend an LPG/Carbon monoxide alarm to be mounted in your bilge or very low in your cabin.

CNG gas system was great, and I think much safer than LPG, but propane sinks and therefore can present a danger. Just learn and understand it. CNG is getting very hard to get refilled.

[boatpoker]

I am a propane user but there are some caveats as there are with any combustible materials. Safe Propane Installations on Boats

[twinboat]

If you don't have thermocouplings on the stove burners you may not be in compliance with insurance regulations.

[pesarsten]

+1 on the thermopiles for the burners, these shut down the gas flow if they cool off ( think burner went out ).

You should be able to purchase gas jets ( metering orifices ) and burner control valves with thermal cutoff protection from any good gas appliance servicer.

[ALAIN97133]

Originally Posted by Uncle Bob

Have you considered re jetting your existing stove ? Not difficult to do and a hell of a lot cheaper...
Agreed on the rejetting. I have gone the other way on a home BBQ. Easy. This issue may be in creating a safe storage locker for the propane. My understanding is that CNG lockers do not need to be vented overboard. LPG lockers do.[/COLOR]

Hi ! I have the same problem: I bought a 1988 Ericson 34 on lake Michigan with 2 unvented CNG bottles in the starboard locker & sailed Sundance to St Barth, West Indies. I was told that there's no CNG to be found east of Florida but I'd like to keep the ss stove which is in great chape (Once cleaned) & change only the 3 burners. Do you know where I can order them ? Also, what's the minimum I have to change ? The injectors if any ?
Thanks for your help
PS: My Ericson has a vented round locker ready to receive a propane or butane bottle once I've changed the burners or the stove.

[rwidman]

Originally Posted by twinboat

If you don't have thermocouplings on the stove burners you may not be in compliance with insurance regulations.

I wouldn't worry about insurance regulations, I would worry about being on board when that big ball of fire hits!

The stove can be converted, but the advice to drill out the jets yourself is bad advice. Buy the correct jets. Make sure your stove has the thermocouple safety shut offs on all burners and the oven. Install an ABYC approved propane locker, a propane regulator, shutoff solenoid and switch and a propane alarm. Also, make sure the lines from the locker to the stove meet the ABYC specifications.

In the end, it may be a better plan to retain what you have and find a source for the fuel.

[Vicki K]

Bacon Sails in Annapolis has lots of used gear, including stoves.


Sent from my iPhone using Cruisers Sailing Forum

[Dsanduril]

re-jetting for propane isn't rocket science, but it does require a little detail.

CNG usually operates at about 4 inches of water column at the appliance, with a range of 3-7. Propane usually operates at about 11 inches of water column, with a range of 10-14. This is for typical appliances we might use on a boat. Hence the smaller orifice for propane, it is mostly because of the higher operating pressure.

You might find this chart useful:

http://www.hvacredu.net/gas-codes/mo...ty%20Chart.pdf

Or this:

Low Pressure Orifice Chart

The first chart has more detail but it's not the most clearly labeled. The top row is the working pressure at the appliance in inches of water column. The chart covers 3-7". For propane they provide the equivalent BTU rating at 11".

Remove a jet from the stove and use a numbered drill set to determine the orifice size. Presuming you don't have a complete numbered drill set you can probably make friends with someone at a machine shop and ask them to measure the orifice size.

Then find the orifice size in the chart. Let's say it is a #64 that would provide 3518 BTU at 4" WC. Head over to the propane column and look for something close to 3518. A #74 orifice at 11" propane will provide 3536 BTU.

Now you can either head to the appliance parts store or the machine shop and see if you can find something close.

[Jenna1]

Just thought I would put in my two cents worth. I'm in the middle of converting a CNG system to propane. I have an older Seaward Hillerange stove/oven. CNG is nearly impossible to get in my area in Canada. I had contacted Sure Marine at Sure Marine Service, Inc. * Since 1972 * Webasto Marine Heating, Air Conditioning, and Galley Equipment and had called them up. They had the jets to convert the stove top and oven (different size). I was advised that my oven control may not work as it should because it was built for CNG. I had ordered a propane locker to keep the boat within the ABYC rules and a propane detector and valve controller. It does add up $$ wise but I would rather be a few dollars poorer than in a boat that blows up :-( I'll let you know how it all turns out in the next week or so. You may also want to look at the Matt & Jessica Sailing Page - mjsailing.com and look under Projects/Maintenance. They have good pictures showing how they did their conversion. Best of luck.

[sailcruiser]

My friend who has a 91 Legend said this:

He put a propane locker that holds 2 11 gallon tanks in the cockpit locker. (Didn't specify side). He said to watch the latches on the locker. His came aluminum and he had to change them to stainless.

Changes orifaces for stove and oven (stressed the oven) and oven thermostat. He changed the pressure hose. Also installed a detection system auto shut off.

He couldn't recall his source for parts but thought it was in California and was a big source for replacement parts.

HTH!


SC

[michaeld]

I too have a Seaward Hillerange... I'm guessing it's a 3132, and it was set up for CNG when I bought our 1985 Kaufman 47. I am also looking for information to convert it to propane. Any updated information on this will be greatly appreciated.