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Small Cabin Forum / Off-Grid Living / I need some propane Help Plz
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funk62
Member
# Posted: 30 Nov 2010 18:02
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Hi: i would like to run a few propane appliances in my cabin....i need to start from scratch and have questions like regulators and size of main pipe coming form the tank...do i use copper or steel pipe for the main lead coming from the tank....what size fittings are most appliances...etc...

basically my cabin back wall is 12 ft. long and would like to start with the propane tank on the outside of the wall ofcourse then fridge on inside then a stove/oven combo then a propane free stand fireplace possiby and maybe a propane light...

do all these items have there own regulators or do i need a regulator at the tank too...and if so what size...

sure would appreciate the help starting from the tank on through...


thx Funkl62

MtnDon
Member
# Posted: 30 Nov 2010 18:11 - Edited by: MtnDon
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What kind of tank is planned? An on ground 200 gallon or larger? Or 20, 40 or 100 pound portable cylinders?

A large tank will usually use dual regulators. A small setup using the portable cylinders can get away with an RV type regulator, as long as it has the capacity to pass enough propane. The regulator(s) are placed outside the building and only the low pressure gas is piped inside.

Each appliance will have a BTU use rating. Add them all up to see what the total would be. The regulator and the main pipe has to be sized to handle that. The pipe can get smaller as you progress down the line in many cases.

The type of pipe (copper, iron, etc) can vary by location. Some states do not allow copper in certain places (underground for example). There are special coated pipes for underground use. Black iron is great above ground.

funk62
Member
# Posted: 30 Nov 2010 18:21
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Thanks for a quick reply....propane size would be no larger then 100 lb. tank and as far as BTU im guessing 60,000
the type of pipe... it will be coming direct through the wall and all appliances will start on the other side of the wall.... from the tank to the furthest appliance will be approx 12 ft. if this helps

does it hurt to over estimate the size of the regulator for future add ons ?????
Funk62

MtnDon
Member
# Posted: 30 Nov 2010 19:37
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I use a two stage automatic changeover RV type regulator on our cabin. Very handy as two tanks can be connected and it lets the first run dry and then automatically switches to the second (full) tank. I believe ours will do something like 120,000 BTU.

I run 1/2" black iron pipe from it through the floor and up inside the wall. With your distances you can do the same. I have three black iron stub outs that pass through the wall spaced along the kitchen wall. Each is fitted with a shutoff valve. They feed the propane fridge, range and water heater. There is a second line that runs to the other side of the cabin for a wall heater.

Depending on the appliance you could most likely run 3/8 copper from the 1/2 iron to each appliance. One appliance per 3/8 branch

hebegbz
Member
# Posted: 30 Nov 2010 21:51
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I use propane for all my heating needs.
Here is how I do it.
My gas range has a 20lb tank under the cabinet right next to it. Lasts about 30 days for normal cooking and baking. Much longer during the hot months when I use my solar oven for almost all cooking.
My single user, on demand hot water heater is hooked to a 20lb tank. Lasts about 60 days for washing dishes and taking showers.
My 22k btu vented wall heater uses a 100lb tank that is right on the other side of the wall, outside. When the temps are 30-50F you can go through 100lbs in 2 weeks. And my cabin is very well insulated.
My gas dryer(paid $25 converted to propane for $30) is in the generator shed on it's own 20lb tank. Only use is in the winter and for things I don't want to hang out. Tank lasts for probably 4 or 5 months.
My point is that normally, your appliances are easier to run on individual tanks, each with it's own regulator.($20 at harbor freight tools) I considered plumbing gas from each appliance to a big main tank but two years later, I'm glad I didn't.
It's hard to haul a 100lb tank around.
Hope this helps.

funk62
Member
# Posted: 30 Nov 2010 22:19
Reply 


Thank you so much for all the useful info.... i jus have one question left... to do with the regulator.... For example.... if all my appliances add up to 60,000 btu's and i use a regulater rated for 120,000 btu's....I'm assuming this is OK as long as i dont go over 120,000 BTU's...am i understanding this correctly....Also... what size regulator does ur average size trailer have on it
Again thanks so much for the info...dealers don t want to tell u anything nor do they want to go to my cab in...lol
Funk62

MtnDon
Member
# Posted: 30 Nov 2010 22:47
Reply 


I have this one on my RV, and a similar one on the cabin. It does 125,000 BTU maximum. I believe that is typical. No problem if you don't use that much capacity.

bobrok
Member
# Posted: 1 Dec 2010 09:01
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I will add this not to reflect negatively on any of the good information given above but just because it has been my experience. I offer this without the knowledge of whether your's is a live-in or a part-time cabin and that could make a difference (I do not live at my cabin).

I have a space heater, RV hot water heater, range/oven and a refrigerator all running off 3/8" copper from one master tank outside. No trunk lines. This is the way it was when I bought my place. I've had service techs do testing and everything passed with flying colors and adequate pressure with everything running at the same time. I was pleasantly surprised with those results.

Point is, if your circumstances are similar it may not be necessary to over engineer the gas distribution system. Everything at my place passes underneath and strapped to the floor joists with T's and shutoffs where necessary.

Of course codes and such are different all over so that will come into play.

One last thing. Just the other day I found out that there is now on the market (in the US at least) plastic high pressure gas tubing. Bendable, flexible, and with Pex-type crimp fittings. I just found out about this from someone the other day and I haven't had a chance to check into it at all. Almost sounds too good to be true.

rayyy
# Posted: 23 Jan 2011 11:12
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hebe,thank's ,great information.I am told that a 20 or 30 pound tank on an RV is not the same as a 100 pound tank.is this true?Pluss it makes sence to put each device on it's own tank so when it runs out it doesn't shut down all your applications.I'd like to here more of your experiences living off grid.

hebegbz
Member
# Posted: 24 Jan 2011 02:48
Reply 


rayyy, I interchange 100lb and 20lb tanks for my heater all the time. No difference. I split my appliances so I wouldn't have to run a bunch of concealed lines that might leak inside my cabin. I have found that the standard "el cheapo" regulator from Harbor Freight Tools will work on your gas range/oven, your vented wall heater, your gas dryer, your on demand water heater, and of course, your bbq. Everything but the heater uses such a small amount of propane that a 20lb tank lasts for a long time.

MtnDon
Member
# Posted: 24 Jan 2011 14:16
Reply 


Depending on the volume of gas the connected appliance requires you will run into situations at lower temperatures where a 20# cylinder can not deliver sufficient gas to operate the appliance. Items like high output propane heaters are one that can be affected by cold and small cylinders. In that respect there is a difference in the 100 pounders.

Kramer
Member
# Posted: 24 Jan 2011 20:53
Reply 


Quoting: hebegbz
My gas range has a 20lb tank under the cabinet right next to it. Lasts about 30 days for normal cooking and baking.



So, is the 20lb tank inside the cabin?

If so, no, that is not a good idea. I doubt it is legal anywhere, and for good reason. If the safety valve pops on the tank, it will flood the cabin with propane vapour. You'll either asphyxiate or die in the resulting explosion.

tahoe98
# Posted: 16 May 2011 19:07
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when running 3/8 copper pipe , how many appliance's can i run. eg. fridge, stove, water heater, lights.

MtnDon
Member
# Posted: 16 May 2011 19:44
Reply 


What you can run depends on the BTU input of each appliance. Without knowing that anyone is guessing. Is that 3/8" ID or OD diameter??

rutland
# Posted: 23 Nov 2011 20:45
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Just wondering how you made out.Its best to use the two stage regulator with 1/2 inch copper to a manifold made from 1/2'' tees nipples then run copper to each app.

Mike9999
# Posted: 26 Feb 2013 15:20
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Can you use two different size propane tanks on a auto switching system? Say I have a 40 lb and a 20 lb..... If it'll work which one will run out first?

Just
Member
# Posted: 26 Feb 2013 15:33
Reply 


yes but,, if you run them'' one'' at a time you will not likely run out [always keep one full ] i have a 20 and a 40 work fine ..

creeky
Member
# Posted: 26 Feb 2013 18:31
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hebe are you running iron lines or what. I notice that bbq style lines come in 10 ft lengths now?
I'm putting in two vented propane heaters and a propane on demand hot water heater this year. I'm looking for an easier solution than iron pipe.
how lazy am I?
http://intercat.phaup.net/images/Wolter%20Water%20Heater2.pdf
is a nice overview of installing a propane hot water heater in a boat. very suitable to small cabin use. Because boats have the propane tank installed inside the cabin it shows good venting and the use of a special cabinet.
Also it appears: there is flexible plastic line that is a stainless line with a plastic cover. me like. but the tees etc are very expensive. there is a polyethelene tubing. but it is said to be only suitable for underground installation.
dang. I need an easy/cheap solution.

tinymora
Member
# Posted: 13 Oct 2013 13:52 - Edited by: tinymora
Reply 


Question: can you have a 1/2 line as the main line coming in to your unit that hooks to an appliance that requires a 1/2 hook up and then increase you line to a 3/4 pipe to hook to an appliance that requires a 3/4 inlet?

bldginsp
Member
# Posted: 13 Oct 2013 14:41 - Edited by: bldginsp
Reply 


Tinymora- If I understand what you mean, the answer is no. I think what you mean is a 1/2" pipe from the propane tank to the first appliance which requires 1/2", then after that appliance the pipe increases to 3/4" for a second appliance downstream that requires 3/4". If this is what you mean the answer is no, because if both appliances are running at once, the 1/2" pipe from the tank to the first appliance is handling propane flow for both appliances at once. Also, if the second appliance requires 3/4", it will require that size at least for the total run from the tank to the appliance.

The longer the pipe run, the larger the pipe has to be to provide adequate flow. An appliance that requires 1/2" pipe on a short run might need 3/4" for a longer run. Also, as indicated above, any section of pipe that feeds two appliances or more must be large enough to handle all appliances at full capacity or else when they are all turned on none get enough gas.

Gas pipe size is a function of total BTUs served by each length of pipe, and total distance from the gas source. There is a slightly complicated calculation required, using a gas pipe sizing chart that shows how large the pipe must be given BTUs and distance.

But in small cabins where the distances are not over 30 feet, these calculations are probably unnecessary. If you have an appliance with instructions to use 3/4" pipe, run 3/4" pipe the whole way from that appliance to the tank.

If you are branching your lines, it's a good idea to be sure your main line is large enough. Here's a link to a page with propane gas pipe sizing charts and some instructions. If you are at all in doubt, get professional advice. A nice plumber should be willing to look at a simple drawing of your pipe system, with lengths of all pipe and BTUs of all appliances, and steer you correctly.

http://www.engineeringtoolbox.com/propane-gas-pipe-sizing-d_827.html

But looking at the charts you'll see that a 3/4" pipe at 40 feet of length will handle 230k BTU (approx.), more than most cabins will use anyway. 3/4" to your first branch at least is a good idea.

If the appliances don't get enough gas the flames wont burn correctly and, I think, can overheat or produce CO.

Please be careful with gas.

Borrego
Member
# Posted: 13 Oct 2013 21:55
Reply 


I'm in the process of doing this now and I am going to use (3) 100 lb tanks run in series to a 'manifold' I'll call it. From there, the galvanized pipe will run under the cabin pretty close to the appliance. (I have stub-outs going down thru the floor) So then I'll use the flex connectors to go between the two pieces of pipe. By flex, I mean CSST. I'll have my plumber make up some 10 foot sections with fittings on the ends.

bldginsp
Member
# Posted: 13 Oct 2013 22:16
Reply 


Remember to bond from your hard pipe to an electrode when you use CSST. Lightning arcing can burn a hole in that stuff. Scary.

Borrego
Member
# Posted: 13 Oct 2013 23:04
Reply 


Yep. Thanks!

tinymora
Member
# Posted: 14 Oct 2013 10:51 - Edited by: tinymora
Reply 


Thanks for the info. So the lay out is like this. line in 3/4 a fryer that requires 1/2 in line then grill that requires 3/4 inlet then two burner stove requiring 1/2 inlet. If I understand we can run 3/4 all the way 12 foot and tee off from the 3/4, 12 foot run to each unit with the inlet needed, stub out 1/2 then stub out 3/4 and finally stub out 1/2 for two burner stove . Would this be correct?

bldginsp
Member
# Posted: 14 Oct 2013 14:33 - Edited by: bldginsp
Reply 


Can't tell from your description. Need a drawing that includes the location of each appliance in the pipe, the BTUs of each appliance, and all pipe lengths. Looks like you are using some high BTU appliances, so you may be out of the realm of the simple.

But, looking at the chart, if your total BTUs are under 400 and your greatest length of pipe is less than 15 feet, looks like you are fine with a 3/4 main line and branches as you describe.

tinymora
Member
# Posted: 14 Oct 2013 15:31
Reply 


Yeah total BTU'S 255k

bldginsp
Member
# Posted: 14 Oct 2013 18:44
Reply 


That's a lot of BTU capacity for a small cabin. What are you doing, cooking double orders of French fries for the bears and raccoons?

MtnDon
Member
# Posted: 14 Oct 2013 19:22 - Edited by: MtnDon
Reply 


Quoting: tinymora
BTU'S 255k


Wow!!

That is more than our home can pull all at once; furnace, range, hot water heater and shop heater. Also there are significant differences between propane and natural gas piping capacity. Use the correct charts.

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