Think I got me a problem with NG line

[stigedis]

So when we built house 5 years ago, I had plumber run soft copper from basement manifold to garage. House all finished. I had intention of building another detached garage in the future and wanted to make sure I had enough pressure/volume so that a heater or boiler for in floor heat to be used in future garage which is now 25 feet from attached garage. Plumber said no problem. Well now it's time to get heater (hanging 60k power vented) set up. Not using in floor heat due to overall cost for boiler etc. but here lies the issue. Never really paid attention to what he put in. 6psi from meter in 1/2 pipe to basement@ 30 feet. He then put 2 psi regulator in, then 4 manifold running 3/8 soft copper to furnace, fireplace, water heater, and the line to attached garage. That line is @ 60 feet. Here is where I took over this summer and ran about another 50 feet 1/2 yellow pipe buried to outside wall of new garage and into location for hanging furnace.
Here's when I discovered the issue. I went to attach the line from attached garage to detached garage and found the 3/8 copper and on the wrong side of the manifold in basement. Easy to put tee in before basement manifold.
But now I'm concerned that the pressure/volume will not be sufficient to supply the 60k but furnace. Will the 3/8 line need to be replaced or at least get 1/2 inch to attached garage to hook into already in place 1/2 inch from garage to garage?
Or (hopefully) will 3/8 inch bumped to the 1/2 inch at attached garage be ok at 6psi. Or maybe the 3/8 inch can't support that pressure and/or be too restrictive to get volume to detached garage furnace?
I really hope all will be ok once I get the 3/8 on the other side of the basement manifold...
Any thoughts from those with more experience? I attempted calculations from online research but got too confused.
Thanks in advance.

 

[CNGsaves]

Are you sure you have 6 psi ??? I've never heard of that.

Around here, most "high pressure" that GasCo's offer is 2 psi. Common residential NG pressure is 7 to 10 in water column . . . only about 1/2 psi.

If you truly have that high pressure, it might work but the 110 ft is very concerning, along with number of elbows involved overall. You will need to plug into one of NG flow charts and see if that high pressure overcomes your long length and number of elbows.

 

[stigedis]

****. No gas at meter reads 2psi. Not sure why I hit 6psi. Regulators are 2psi. Long runs is why I wanted copper and not black pipe. There will be some elbows with in/out garage walls. Am planning as few as possible with 45s where they will work.

 

[stigedis]

IF I ran CSST from basement to end of attached garage, maybe the best to do with that long run? Will now be a little longer as I'll have to go thru attic and drop down......uugh

 

[CNGsaves]

^ ^ ^ Don't think I'd go with CSST as ribs will slow your flow.

Given your situation, you may need to Upsize the 30 ft from meter to the manifold (copper or black pipe steel), then T between manifold and connect your long run direct to other half of T (ie not the shared manifold). If you have 2 psi the whole way, I bet your 3/8" copper and 1/2" yellow plastic will be alright at 110 ft to the detached garage 60K Btu heater.

Another trick is Upsize the last several feet right before the heater, so like 1" black pipe steel.

 

[Falcon67]

http://www.engineeringtoolbox.com/natural-gas-pipe-sizing-d_826.html

You may need 3/4" to feed 60K BTU. The big convection gas stove we used to have required a 1" line and it was 30' from the meter.

 

[BillK]

I would call the gas company and ask their advice. They might be able to up the pressure at the meter and then you would have to use regulators at each appliance.

That is what we had done at the last shop I was in to allow us to use our parts baking oven without re plumbing the entire building.

 

[zmaxmotorsports]

Are you sure you have 6 psi ??? I've never heard of that.

Around here, most "high pressure" that GasCo's offer is 2 psi. Common residential NG pressure is 7 to 10 in water column . . . only about 1/2 psi.

If you truly have that high pressure, it might work but the 110 ft is very concerning, along with number of elbows involved overall. You will need to plug into one of NG flow charts and see if that high pressure overcomes your long length and number of elbows.

 

[nh_yota]

I thought copper couldn't be used for natural gas?

 

[R.Anderson]

You will need to have the pressure at 2psi through 3/8" copper at that distance. 7" is not enough pressure to feed a 60K BTU furnace through a 3/8" line at that distance. I just had to do this for a 120ft run with 3/8" copper feeding a 60K BTU furnace. At the furnace you will need a regulator to drop to 7" for the furnace that should cost about $18 add another $8 if you put it outside for the outdoor vent cap.

But a good part of the line is 1/2" but I think that still is not big enough. Would need to do the math.

It is not the 3/8" line that would concern me. It is every thing before that. 30ft of 1/2" pipe @ 2psi feeding water heater, fire place, house furnace, and now garage furnace. All this needs to be calculated.

 

[stigedis]

@R. Anderson:
So before I get to redoing pipe sizes, you ran 2 psi in 3/8" at 120'? So since the 3/8" is only a portion (in the middle of my whole run), as long as I get 2psi the entire run (with of 1/2", 3/8", back to 1/2") then with regulator at 60k BTU I should be good? Please clarify as I am unsure what the 7" is in reference too. Excuse my ill-knowledge. That's why I love this forum. I am hoping this is the case. Would make my week!
Thanks for the reply all.

 

[R.Anderson]

@R. Anderson:
So before I get to redoing pipe sizes, you ran 2 psi in 3/8" at 120'? So since the 3/8" is only a portion (in the middle of my whole run), as long as I get 2psi the entire run (with of 1/2", 3/8", back to 1/2") then with regulator at 60k BTU I should be good? Please clarify as I am unsure what the 7" is in reference too. Excuse my ill-knowledge. That's why I love this forum. I am hoping this is the case. Would make my week!
Thanks for the reply all.

Yes 120' of 3/8" copper @ 2psi with a regulator dropping to 7"WC prior to the furnace.

Maybe, I would be concerned about every thing being feed off off the 30ft of 1/2" @ 2psi from the gas meter. If every unit were to run at the same time there maybe issues. Calculations would need to be done. Or just try I guess.

7" is the pressure the regulator drops the pressure to (7 inch of water column) I should of added WC.

 

[stigedis]

Great! Thanks for input/info

 

[mygarageone]

I thought copper couldn't be used for natural gas?

You are right . It flakes like crazy . But I've seen a lot of it , in fact the gas companies used to use it from the main to the meters but they figured out that's not a good idea !

 

[CNGsaves]

^ ^ Different parts of the country just love copper. Guys in Minnesota swear by it and common setup is coiled copper that they straighten out and route through the house under construction. Guess it makes for quicker installation than black pipe steel.

I'm old school and like black pipe steel.

 

[stigedis]

so here's the update....
Went with original plan and got 3/8 pipe before regulator in basement for full 2 psi through 3/8 pipe and into 1/2 pipe from attached to detached garage. Manometer at detached garage before regulator reads 50.4 inches of water column and 1.8 psi. Its not full 2psi, but after install of industry standard regulator i think I will be ok for the 60K hanging furnace? I hear stories about too low pressure after firing the furnace. I know i should check pressure with furnace running, but initial thoughts?
Any comments would be appreciated.

 

[CNGsaves]

^ ^ ^ You've got great option with the GasCo there in MN if you've got 2 psi after the meter. I think you'll be fine as your regulator out at detached garage will be taking it down from 2 psi (ie 1.8 psi actual) to 7 to 10 in water column (ie approx 1/2 psi or less).

Your only worry is what pipe length you'll have from the regulator to the hanging heater to handle the 60K Btu. If it's a long run, a safe bet would be to run 3/4" black pipe steel all the way to heater since you're dealing with low pressure after the regulator.

 

[HoosierBuddy]

If I'm reading he OP correctly that he's measuring pressure without the heater running...then that doesn't mean anything.

With no flow, you'd have full pressure on the end of your pipe REGARDLESS of pipe size. The only thing that matters is can you maintain 6-inches w/c (or whatever the heater requires to run right) downstream from your appliance regulator at the unit heater with the heater running.

So...hook it up...fire it up...and see if you can maintain the required pressure. Until then, you won't know.


Phil

 

[stigedis]

@HB....you are correct. I will need to check when furnace is fired up and running (with other demanding appliances too i would assume). But i was under the assumption that if sized improperly, pressure would even be really low at terminal end regardless.
So yes that is the plan, but i am a little more optimistic. Maybe a bit prematurely?
Thanks guys

 

[HoosierBuddy]

@HB....you are correct. I will need to check when furnace is fired up and running (with other demanding appliances too i would assume). But i was under the assumption that if sized improperly, pressure would even be really low at terminal end regardless.
So yes that is the plan, but i am a little more optimistic. Maybe a bit prematurely?
Thanks guys

Yes. Premature. With no flow the line could be 1/100 of an inch and you'd get the same pressure readings as a line that was 4-inches.

You might consider buying an inches w/c gauge and leaving it plumbed in downstream of the regulator if you're going to really want to keep an eye on it. I put one just ahead of the boiler in my garage. Sort of interesting to watch I guess....if you're obsessing over it.

https://www.amazon.com/dp/B00PR053YQ/?tag=atomicindus08-20

Phil

 

[R.Anderson]

so here's the update....
Went with original plan and got 3/8 pipe before regulator in basement for full 2 psi through 3/8 pipe and into 1/2 pipe from attached to detached garage. Manometer at detached garage before regulator reads 50.4 inches of water column and 1.8 psi. Its not full 2psi, but after install of industry standard regulator i think I will be ok for the 60K hanging furnace? I hear stories about too low pressure after firing the furnace. I know i should check pressure with furnace running, but initial thoughts?
Any comments would be appreciated.

Is your natural gas supplier Xcel? If you are certain you are not getting 2psi when nothing is running you may need to have them come out and bump it up to 2psi. But do not worry about it unless you do not have enough gas flow.

@HB....you are correct. I will need to check when furnace is fired up and running (with other demanding appliances too i would assume). But i was under the assumption that if sized improperly, pressure would even be really low at terminal end regardless.
So yes that is the plan, but i am a little more optimistic. Maybe a bit prematurely?
Thanks guys

Yes, test with all units, if your furnace is a two stage or full modulating make sure it is burning at high fire when you take your final reading at the detached garage furnace.