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SandwichBear
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# Posted: 13 Nov 2013 05:37pm
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I'm putting together a propane system for my tiny house in-progress. This is my first time working with propane, aside from hooking up a BBQ. Let me explain my plan and show a couple photos - if anything seems sub-par or improvable, please let me know.
I have two appliances: a Dickinson P-9000 heater, and a vintage oven/stove from a travel trailer.
I have an automatic changeover regulator coming in the mail. I will hook this up to two 20lb tanks in an enclosure to-be behind the house.
From the regulator, I will use a black flexible BBQ hose to connect to a 78" long run of black iron pipe via a 3/8" flare to 1/2" pipe-thread adapter. The 1/2" black iron pipe will have two iron tee fittings along its length, and an elbow at the end. From one of the tees and the elbow, I will run a 2" iron nipple to a shutoff valve with a 3/8" flare fitting. (See photo.) The extra tee fitting will have a black iron cap - my thinking is that I can add an appliance here in the future if I see fit.
I intend to run the black iron pipe along one of the skids that my subfloor is attached to. (See pic.) From the 3/8" flare side on the shutoff valves, I will run 3/8" OD copper tubing up through the subfloor and directly to the heater and stove. I bought a flange tool.
Any suggestions on a clean way to pass the copper through the floor? A grommet of some type? A piece of PVC or something? Just silicone it?
Does any of this raise a red flag? Should I be insulating the outdoor sections of pipe in some way?
It looks like I will have a challenging angle from the flares on the shutoff valves up through the floor. Is there a better arrangement? Do I really need these valves at every junction?
I've read that a bicycle pump can be used to check for leaks if you pump 10psi into the system. Any advice on how to attach the pump head to a piece of pipe? I'm a bicycle mechanic, and this does not seem obvious. Perhaps I should stick to traditional soapy water method?
I got the correct (yellow) tape. I will use it on all the male threads, and make the connections "good and tight" before checking for leaks.
All input is appreciated and will be considered.
pipe along skid
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tee junction
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bldginsp
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# Posted: 13 Nov 2013 05:58pm
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You don't need a valve at every junction, but you do need one at every appliance so it's easy to shut it off in case of a problem or to disconnect it. No need to insulate the pipe, but remember that the colder propane gets the less delivery pressure you get from your tank. The solution is larger or more tanks, if this is an issue.
For testing they make a fitting that has a typical bicycle Schrader valve for pumping up the system. The fittings come with a gauge on them, or without a gauge. Kind of costly, but its a good idea to kick the pressure up to 10 lbs or so for the test to be sure the system is tight. Obviously no drop in pressure at the gauge shows no leaks, and you can do a soapy water test to find a leak if one exists. But just doing a soapy water test on the line under pressure from the tanks is not necessarily the best test, since the tank regulator only allows a very low pressure.
What you don't want the copper lines to do that pass thru the floor is to rub constantly against a hard surface. With standard corrugated gas connectors, this rubbing can eventually rub a hole in the connector, making a leak. I don't know if this would or could happen with copper, but I'd guard against it by using caulk around the opening, which will also seal from a draft.
Is 3/8 tubing large enough for the btu requirements of the appliances?
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SandwichBear
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# Posted: 13 Nov 2013 06:27pm
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My thinking with the shutoff valves being outside is that I will have fewer fittings, or "leak opportunities," inside the house. Keeping with my current proposed system, I will still be able to isolate each appliance individually from the main tank(s).
The house has a 8'x12' footprint. I can hop out the front door and have an appliance shut off in less than 5 seconds as it stands. Good enough?
Since the house is stationary, there will be little or no abrasion to the lines or "rattling of the pipes." I will still make an effort to protect the copper where it goes through the floor, and keep all connections solid. Current plan: silicone caulk.
My primary concerns are that 1) I'm using the correct materials and methods, and 2) I'm not over-engineering something that could be made meaningfully simpler.
Most of my fittings are still in packaging, and I have the receipt. Now's the optimal time to get it right.
Thanks,
Chris
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MtnDon
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# Posted: 13 Nov 2013 07:45pm
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Quoting: SandwichBear From the regulator, I will use a black flexible BBQ hose to connect to a 78" long run of black iron pipe
I don't understand this. A regulator is normally connected direct to the black iron pipe. Hoses are used between the propane tanks and the regulator. Using a pipe union between the regulator and the black pipe run can make that easier. Makes future service on the regulator easier too.
20 LB tanks may not be able to supply sufficient volume on cold weather. When the tank level starts to get low that can get worse. There is a propane facts topic in the resources section here IIRC.
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Maybe a personal thing but I like Rectorseal pipe dope better than any tapes. Messier but a better seal IMO.
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Quoting: SandwichBear check for leaks if you pump 10psi into the system.
Yes 10 psi works. Buy an adapter or make one with a pvc pipe thread cap and an automobile tubeless tire valve stem. Drill a hole in the cap end, insert valve stem from inside, pull into place. Seal with silicone if necessary but if you get the hole the right size there is no need.
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hand tighten the pipe fittings then usually 2 to three complete turns with the pipe wrench. It IS possible to overtighten... there should still be some threads visible once the pipe is screwed in. I've seen fittings split from turning in too much.
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SandwichBear
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# Posted: 13 Nov 2013 08:10pm
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As far as the flexible hose from regulator to black pipe - I suppose I can make a solid connection once the tanks and regulator are secured in place. Maybe I should have gotten longer pigtails to make placement a little easier. Maybe I will see that this connection IS easier once I have all the parts in place. Chalk this up to preliminary thinking - I'll see about making a solid connection once the parts are all present.
Thanks for the pvc / valve stem tip. I can certainly manage that. Thanks for the pipe tightening tip - that's a better guideline than 'good and tight.'
Please confirm: YES to tape/dope on the black pipe male fittings. NO to tape on the flared brass fittings? (I saw one video with tape used on a flared fitting, and one video using none. My instinct is to trust the NONE option.)
I might re-arrange some of the details of the fittings, but if the basics of this setup seem good in principle, then I will move forward when the parts arrive.
Thank you,
Chris
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MtnDon
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# Posted: 13 Nov 2013 08:38pm - Edited by: MtnDon
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Please confirm: YES to tape/dope on the black pipe male fittings.
YES, for certain.
NO to tape on the flared brass fittings?
NEVER tape or dope on flared fittings
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SandwichBear
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# Posted: 13 Nov 2013 08:51pm
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GOOD. Thanks for the CAPS, this is something that I will NOT MESS UP! 
Specific changes I'm considering:
1) Move the valves inside. Install this valve: http://amzn.com/B0046HAANU in line with the copper tubing supplying the appliances.
2) Use this fitting in place of the nipple and valve exiting the iron tee fittings.
Then I'll have indoor shutoffs and a simplified connection at the supply pipe. That would be great! ... right?
I was not able to find information about low-temp pressure concerns in the resource section. I will be looking into that now. Would narrower black pipe help? 1/2" was the smallest diameter where I got my supplies, but maybe I can look elsewhere. I would also consider a larger tank - up to 40 lbs, I think - if pressure becomes an issue. I am in SE Pennsylvania, where the temperatures don't often go below 20 degrees in winter. Colder days happen, though. We get into the negatives, but it is pretty rare.
I have the distinct advantage of building 150 feet from my folks' much LARGER house. It's been a blessing throughout my learning process. If it's -18 degrees and my propane cuts out, I can order a bigger tank on Amazon Prime while sitting by their fire.
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toyota_mdt_tech
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# Posted: 13 Nov 2013 09:17pm - Edited by: toyota_mdt_tech
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The copper flares must be double flares, not a single flare. I suspect 3/8" is fine, but not for both appliances. You will need to use a 3/8 for stove and another 3/8 for the heater feeding off the main trunk.
Anything BBQ isnt specs for a cabin, same with RV appliances, but doesnt mean they wont work perfectly. Just some extra FYI stuff. I use an RV stove/oven in mine.
If you are anchoring down any copper, do not let any metal other than copper touch it. I used those metal band clamps with the rubber insulator inside it. The transition from brass to copper is fine, and black pipe is perfect also. No galvanized of any kind (Galvanic Corrosion = leak = poof/boom).
Here is the clamp.
http://www.amazon.com/Stainless-Steel-CUSHION-CLAMP-pack/dp/B000NI3CJ0/ref=sr_1_2?ie= UTF8&qid=1384395302&sr=8-2&keywords=stainless+cushion+clamp+3%2F8%22
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SandwichBear
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# Posted: 13 Nov 2013 10:06pm
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Thanks for the input, and good heads-up on the clamps.
This is the first I've heard about double flares. All of the info I've read or watched has been a simpler single flare.
As it stands, my plan has a 1/2" black iron feeder pipe supplying two 3/8" copper lines - one for each appliance.
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MtnDon
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# Posted: 13 Nov 2013 10:30pm
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I believe NFPA permits 45 degree single flare connections for both LP and Natural Gas in homes, BUT the RVIA (RV Industry Association) has a different rule. RV's now require the double flares because they move and vibrate and the double offers better protection against mobile failures. Same reason that RV's can not use the common yellow flexible pipes that can be used in buildings.
Nothing wrong with using double flares in a home, but not necessary, if my info is correct.
I think I listed this link to propane pipe sizing before. Use it to be sure the 3/8 copper is adequate. My bet is that it is okay as long as the distances are relatively short. IIRC 3/8 copper is good for up to 40,000 BTU per hour up to 35 feet and 1/2 iron for about 100,000 to 35 feet. Worth checking before doing all the work.
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SandwichBear
Member
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# Posted: 14 Nov 2013 12:40pm
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Single flares, double flares... looks like the tools cost about the same, so double flares, why not? I'm double-flaring it up.
Thanks for the propane info links. Bookmarked. Judging by the tables, it looks like I will be fine, but with less of a margin than I assumed. There's nothing better than knowing how things work, and when/why they might stop working.
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toyota_mdt_tech
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# Posted: 14 Nov 2013 12:51pm
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Quoting: SandwichBear Single flares, double flares... looks like the tools cost about the same, so double flares, why not? I'm double-flaring it up.
Right on. I got my info when installing a propane furnace in a cargo trailer of mine, I just assumed it meant all gas lines, but they knew it was on a mobile rig. But if the tool is the same price...
Nice thing about the double flare tool, it can still do single flare also. 
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SandwichBear
Member
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# Posted: 30 Nov 2013 03:09pm
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UPDATE:
I have the Dickinson P-9000 installed, but I have some issues. I did a test burn for a few hours, and found that there was a good amount of soot on the glass. I don't know how much soot is normal - I think just about NONE - but I had the glass window halfway to black in a couple hours.
What would cause this soot? After much research, I found two possible causes (possibly both incorrect). 1) maybe my copper pipe was too kinked where it enters the house. I double checked, and it doesn't look like it. It is only very slightly flattened, and I don't believe it is enough for any obstruction. I doubt that's the issue. 2) Dickinson stresses that the smaller-diameter flue pipe in the double walled chimney must be carefully sealed against the flue collar. Dickinson recommends muffler tape or tin foil to get an "air tight" bond.
I don't see how it is possible to use muffler tape. The inner chimney pipe slides over the flue collar, and the recess is quite narrow. Even with the tiniest longest fingers in the world, you could not wrap muffler tape around this joint. I must be misunderstanding something. Any hints?
Perhaps related to this, perhaps not, the heater doesn't get warm enough. My test burns were in 30 degree weather. My house is only 8'x12' with an 8' high ceiling and a loft above. Is it possible the P-9000 is underpowered for my needs?
Any tips or insight would be very appreciated.
Thank you as always,
Chris
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MtnDon
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# Posted: 30 Nov 2013 03:15pm
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Altitude?? Propane burning devices need to have the orifice changed to smaller for higher and higher elevations. Depending on the mfg that can start to be necessary at 2000 feet and above.
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SandwichBear
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# Posted: 30 Nov 2013 03:24pm
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I'm only a few hundred feet above sea level. Southeastern PA.
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