new LP gas line sizing question

[LBrown59]

At our last house, I had paid someone to run a natural gas line underground from the house to the unattached garage. That plumber wanted to use copper, but I was a little leary since I had never seen copper used in this area for natural gas. I still haven't since that time either.

The gas company here used to let you use copper tubing but not any more in most cases. I was able to use 3/8 flexible copper tubing to hook up a heater in a stall in my Metal pole building a month or so ago. An exception was made since the heater wasn't being installed inside a residence.
You can use the Yellow Plastic Gas Line out doors but it's not permitted inside.
I used it back around 1998 to replace the old rusty leaking one inch black steel pipe at my parents place.
3/8 or 1/2 feed lines from the line that runs from the meter to the house are adequate for most residences.
Anything is better than steel pipe if you can avoid it.

 

[srossman]

As for sizing for LP gas, it depends if it is inside the house or outside from the tank to the house. Usually, there is an "A" or high pressure regulator at the tank which reduces the pressure to 10 PSI, and then a "B" or low pressure regulator which reduces it to around 10" - 11" WC inside the house. Obviously, the line can be much smaller at 10 psi then at the 10" WC to carry the same amount of gas.

To size the low pressure line you need to know several things. First, how long the pipe is from the regulator to the farthest destination and second, how many BTUs are required by all the appliances on this line. Generally you figure about 1" WC pressure drop with all appliances firing at the same time, and then use the table to determine what size pipe to use. The pipe can be quite a bit smaller for LP then for natural gas because the pressure is higher and the BTU content per cubic foot is greater.

Right now the tank is sitting beside the house. Eventually I will be moving to a larger tank and it will be at least 10 - 15 ft from the house.

The longest the main run will be is about 30 ft (That's how long my house is). The maximum number of BTU's will be 199,000 for right now. It will eventually go up with a new gas cooktop that I will be installiing, but for now it will only be the water heater.
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

 

[LBrown59]

I ran 1/2" soft copper tubing for my dryer and gas stove. Gas dealer said that 1/2" would have been enough, unless there was a lot of demand all at once.

My Gas Co. don't allow copper tubing.They usta did but no mo.

 

[LHoyer]

Try this link to Rego LP-Gas Serviceman's Manual. Downloadable PDF. RegO® Products LP-Gas Service Manual

 

[LBrown59]

Right now the tank is sitting beside the house. Eventually I will be moving to a larger tank and it will be at least 10 - 15 ft from the house.

The longest the main run will be is about 30 ft (That's how long my house is). The maximum number of BTU's will be 199,000 for right now. It will eventually go up with a new gas cooktop that I will be installiing, but for now it will only be the water heater.
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

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.

 

[srossman]

Try this link to Rego LP-Gas Serviceman's Manual. Downloadable PDF. RegO® Products LP-Gas Service Manual

That's a great resource thanks for supplying it.

 

[LBrown59]

At our last house, I had paid someone to run a natural gas line underground from the house to the unattached garage.

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

 

[Egon]

The age old question! Do you need a permit, must it be installed by a qualified person, will there be an inspection and pressure test and what does the insurance company say?

There should be some pretty standard specifications for your area that you should check into and adhere to.

 

[LBrown59]

The age old question! Do you need a permit, must it be installed by a qualified person, will there be an inspection and pressure test and what does the insurance company say?

There should be some pretty standard specifications for your area that you should check into and adhere to.

who are you replying to with this?

 

[flusher]

Hi everyone, I was hoping someone could shed some light on a question that I have. I'm in the process of putting gas lines in my house and am trying to figure out the proper size to buy. For right now, I installing a tankless water heater which requires a 3/4" line. In the future I will also be installing a gas cooktop and if the electric furnace ever goes, I'll put in a new gas furnace also. I want to get everyting plumbed out now, so that when I am ready for the stove, it will be easy to hook into the line. Right now the run from the tank to the water heater is about 18 ft if that matters.

Thanks for all replies,
Scot

Last year I had my LP gas supplier install 1" black iron pipe about 115 ft in length from the 250-gal tank to my house. I have a gas furnace, water heater, range and clothes dryer. No problems.

I dug the trench.

Cost about $350 for the gas line install.

Plastic line was an option, cost a little less since it's a one-piece length instead of several 20-ft pipe sections that have to be screwed together. But I have gophers and ground squirrels around the almond orchard that's close to the gas line, so metal pipe seemed a better choice.