Water & Gas Line Size

[MMH]

I will be running a PEX water line to my pole barn. Will a 3/4" line be big enough for a 120' run, or, should I go to a 1"? Will use the water to wash things down, run a pressure washer, etc.

Also will be running a natural gas line. Will 1/2" be big enough or should I go 3/4"? What kind of gas line is typically run outdoor/underground?

 

[sdkubota]

Run the 1" on the water and the 3/4" for the gas. The cost savings to go with the smaller size would be minimal.

 

[GPintheMitten]

Check with your building dept on type of gas line and other specs.

 

[greasemonkeyok]

Use pipe that is made for natural gas and meets code. If your water line leaks, your risk is mud. If your gas line leaks, someone can get seriously hurt or killed.

 

[Raspy]

Nobody can tell you what size gas line to run unless they know what you'll be running with it.

Bad advice is worse than no advice.

Find the BTU rating of the water heater or other device you'll be using. Add all of them together if more than one, measure the overall length of the pipe run and go to the code book. The chart for gas pipe sizing is easily found online.

 

[Stimw]

I ran 1" PVC from my pump 100' to my house then ran 3/4" PVC 100' from the house to my 2000 sqft shop. I keep my pump 35-55 psi and I have exellent pressure and volume!
PVC is so cheap and easy to install and repair or add on to that I would re-think the PEX.

 

[Raspy]

I agree that PVC is probably a better choice for price and ease of working with it.

If you do use PEX, be sure to use the one approved for domestic water use. It will have a rating stamp or say domestic water on it. 3/4" will work, but if you add more bibs or want a bit more flow later, or just more running pressure, go up to 1". I'd run Schedule 40 1" PVC for the ease of doing it with readily accessible fittings and easy repairs later if needed.

 

[kenmac]

Nobody can tell you what size gas line to run unless they know what you'll be running with it.

Bad advice is worse than no advice.

Find the BTU rating of the water heater or other device you'll be using. Add all of them together if more than one, measure the overall length of the pipe .

I agree ! :thumbsup: :thumbsup: this ToolKing.com: Tru-Flex Metal Hose Llc PFCT-3475 3/4-inch x 75-foot Corrugated Stainless Steel Hose Coil - FREE Shipping Eligible this what I use for under ground gas line. I like pex over PVC for water.Just be sure to install a tracer wire for both so, you can locate it if you need to later

 

[Qapla]

I'd run Schedule 40 1" PVC for the ease of doing it with readily accessible fittings and easy repairs later if needed.

I agree that the 1" PVC would be just fine. The fittings are readily available and it has been a proven pipe for use underground. As far as schedule 40, I would opt for "thin-wall" like is used for irrigation. It is sold in Lowes and Home Depot as well as irrigation suppliers. Irrigation suppliers usually carry it in 20' lengths with bells while some home centers only carry 10' sticks that need couplings.

You will get better flow through the thin-wall since the inside diameter is larger then schedule 40. Once buried, thin-wall is just as durable as the thicker walled pipe.

It might be a good idea to use the schedule 40 for the pipe that comes up from the ground and into the building as it is a bit more resistant to damage. They both use the exact same fittings.

When properly installed, thin-wall will hold pressure just as good as the thicker pipe.

As far as pipe size, this may help:

At normal pressure and flow, thin-wall 3/4" pipe only passes 9-11 GPM while 1" passes 15-18 GPM. A step up to 1 1/4" will jump the flow up to 25 GPM - as long as your supply is delivering that much. Schedule 40 flows a little less.

 

[BeezFun]

I wouldn't use PVC or pex for that kind of water run, I'd use polyethylene plastic pipe like they use for wells. I ran 200' of it out to my barn, used 1". It's also a lot cheaper than either PVC or pex. They make it in 100psi rating, but I'd buy the 200psi, the wall is thicker and gives you better protection against rocks and damage. It comes in long rolls so you can run it without having any joints except at the end. If I had it to do over I'd throw a second pipe in the trench, it's so cheap compared to the labor that if you ever have a leak, just switch to the other pipe.

For the gas they make a special flexible pipe that you can use, it's yellow around here, not sure if that's standard or not. All the other advice is correct, figure out what appliances you're going to be running before sizing the pipe. Also check your gas meter to make sure it can deliver the extra load. People often have to change their meter when they buy backup generators because they require so much flow, for example. I'd at least think about hiring someone to do the design on the system, even if you still want to do it yourself. The gas company will provide some help around here sizing the meter, not sure where you live.