new LP gas line sizing question

[JerryG]

I have one inch black iron pipe to run 1.2 million BTUs. I don't remember the pressure.

 

[Egon]

who are you replying to with this?

Was there not a question asked to start the thread?

The original question inferred there may be other questions!

 

[Ken_CT]

I was thinking that I would run 1" black pipe the length of the house and then put in T's at all the places that I might need gas. I know that the water heater has a 3/4" input.

So is 1" too big, too small or just right for the main run through the house?
Scot

I'm old school, I prefer black iron for gas lines. 1" is larger than you need but it won't hurt anything except your wallet. One thing that is very important in using black pipe is to only use malleable fittings, not black cast iron fittings. Cast iron fittings will break if distorted, and if there is a fire and something moves the malleable will move (to a point) but bci shatters. I was told it is not a good idea to have an open gas pipe dumping gas into a building that is on fire. You can differentiate between the two as BCI has a wide shoulder, and malleable has a thinner shoulder. Be sure your valves are AGA approved. Also remember it's valve first, then union. Many people now are using the Wardflex system or trac piping. You are supposed to be licensed by wardflex to buy their stuff, but who knows, I got my Wardflex cert many years ago. If you use teflon tape be cautious because the teflon can get into the pipe and clog an orfice, although this is extremely unlikly IMO. I still think a good pipe dope is better for gas piping. Gas pressure is very low in the house, everyone states it as inches of water or water column, and 1" equal .0361 psi, but still check all of your joints with air pressure before using the system, making sure all the valve to the appliances are off.

 

[AndyM]

I don't recall ever seeing that big of a gas line in any house.
Most I have seen are either 1/2 or 3/8.

My main line running across the house in the basement is one inch and the branch lines are 3/4 and 1/2, but I have natural gas not LP.

 

[AndyM]

I've never paid some one to run gas or water lines.
Always did it my self.

At the time, I lived on a city lot and felt it was best to pay someone to do a project like that.

I didn't want this happening...
http://www.tractorbynet.com/forums/rural-living/83815-gas-line-problem.html

 

[kmdigital]

I was thinking that I would run 1" black pipe the length of the house and then put in T's at all the places that I might need gas. I know that the water heater has a 3/4" input.

So is 1" too big, too small or just right for the main run through the house?

Thanks
Scot

1" is a LOT more than you need for LP gas. If you think you may ever go to natural gas it would be good, but for LP gas I would drop down to at least 3/4", and even 1/2" would be enough and is a whole lot cheaper and easier to install. Since it is smaller and lighter it is easier to thread and you are also much less likely to have leaks because it is so much easier to work with.

I have found that most sizing charts use a very minimal pressure drop which requires larger pipe than you would otherwise use, but after years of sizing and running pipe according to these low pressure drops I started using slightly higher pressure drop charts. It works just as well and is much cheaper and easier to install due to the smaller pipe sizes. In other words, instead of using 1/2" WC pressure drop as spec'd by most charts use 1" WC pressure drop as the design parameter, and save a bunch of time and money. It has never failed me in 1000's of feet of gas pipe installation, and has saved lots of money.

Bottom line, if there will never be any natural gas available, I would use 1/2" black pipe due to ease of installation and cost factors. Otherwise, use 3/4" and avoid 1" unless you really like to work and spend money needlessly.

 

[kenmac]

If you are going under ground , you can't beat plastic. With plastic (not pvc)you don't have to worry about corrosion.With propane , some companies offer you a 5 or 10 # system that allows you to run a smaller line & install a pounds to ins regulator just b -4 the appliance that you are connecting to bring the pressure back form 10 pounds to 11- 11.5 inches water column.I have nat gas & I have a 2 pound system in my house. My house s piped with copper( full basement) nat gas causes copper to scale over time & it will clog up your screen at your gas valves. Note : b-4 you can size your line you need to know how many feet from your tank to your house & the total btu that the line will supply

 

[ruglad03835]

Ok I just stumbled on onto this thread. You said you were going 20' +/- to the heater? My question is this. What is the total btu load of the heater? Also I noticed that you were talking about future appliances. Next question what is the farthest distance these appliances are away from the tank or 2nd stage regulator? I see you want to run copper. The on demand hot water heaters I sell (Nortiz) run 190,000 btu's on high fire and there is NO WAY you are going to carry that load through copper. If you want go to Welcome to RegO® Products Online! and download the servicemans manual. There are sizing charts there that you can use. I do this sort of thing for a living and it's not as hard as you think.

 

[kenmac]

My gas code book list 200 ft of 5/8 copper is good for 266 C.F.H.. at 2psi. 7/8 copper is good for 684 C.F.H. at 2 psi. That's in range to burn most appliances for the home

 

[AndyM]

My mother's new condo uses the orange flex hose throughout for natural gas.
It's the first time I've seen the product. I would think it could be used for LP also.

I did a search and found a picture... flex hose link

Anyone here use it?