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Tukeeman 11-28-2008 09:35 AM

Add natural gas line
 
I have a 1.25 inch incoming gas line to my 2 story home. This feeds 2 fireplaces ( 1 upstairs , 1 downstairs) that are close to one another. It also feeds a hot water heater.

Former homeowner teed off the water heater line ( 1/2 inch) located in the garage and added 2 runs. One run of black pipe , 1/2 inch, to the laundry room that is approx 25 feet. Another 1/2 inch run to backyard (wrapped black pipe) for BBQ grill that is approx 70 feet. The measurements are based on actual pipe feet.

The hot water heater has a cutoff valve, as does the BBQ run. Actually the BBQ has 2 cutoffs - one in the garage near the T and the other at BBQ stub.

The laundry room stub has a cutoff valve right inside the room.

I want to do 2 projects.

Project 1

First, I have never used the gas dryer stub and I want to move it. The pipe is installed along the garage baseboards and crosses my home entry bottom sill. I don't like it there.

Since I do not have a cutoff valve at the T for the dryer line, I plan on cutting off the gas at the meter.

I will allow the gas water heater pilot light to shut off and then shut off the valve.

I will open the BBQ valves and let it bleed. Then I will shut off the BBQ valve.

Then cut the dryer line pipe near the T and remove the entire 25 feet of pipe.

Install a 4 inch pipe and a new cutoff valve at the T . I can use this line for other purposes.

Finally, open the meter valve, open (slowly) the water heater valve, open the BBQ valve. Check for leaks using the soapy water method. Relight the water heater.

Project 2

I want to relocate the BBQ. Basically move the stub about 10 feet and add a small firepit ( 18" burner). Total additional pipe feet is about 15 feet. The total linear distance from the meter to the new BBQ stub is approximately 70 feet.

I will use the 1/2 inch pipe removed in Project 1, wrapping it in 20ml PVC pipe tape ( from HomeDepot).

Here are my questions.

Is the plan for project 1 for gas shutoff, bleed, and cutting the pipe reasonable? Have I missed a step? Is there a better alternative? I am concerned about air in the line after I cut the pipe, and the relighting steps. How do I ensure that air is bled from the lines before relighting the heater and BBQ? Can I use the newly installed stub and cutoff valve to bleed the air by attaching a hose , taping it well, and running outside the garage? What about the 2nd story fireplace?


For Project 2.

When estimating BTU throughput, do you measure the linear distance from the meter to the farthest stub, or do measure the actual pipe distance, with all turns and elevation changes?

Thank you.

Clutchcargo 11-28-2008 07:21 PM

I'm not a pipefitter but I did do something similar to my gas lines. I upsized the T off the meter so that I had two 1" lines.
I shut the gas off and turned and vented the line through the stove. I then sawzalled the pipe and tore out all out.
When it came to turning the gas back on, I just turned the stove on for a few seconds, let the gas clear and it worked fine after that.

To determine the pipe size you also need to take into consideration the friction losses due to the elbows, T's, valves, etc.

Termite 11-28-2008 09:32 PM

Quote:

Originally Posted by Clutchcargo (Post 191225)
To determine the pipe size you also need to take into consideration the friction losses due to the elbows, T's, valves, etc.

Nah, you don't. Pipe sized in accordance with the International Fuel Gas Code is based on the farthest gas appliance in the house from the meter in feet of pipe. For instance, if your fireplace is the farthest from the meter at 70' of pipe, you use the 70' column in the chart for every single piece of pipe in the house. To size each individual run of pipe, the btu/h load on that section of pipe must also be known.

I can help you with the pipe sizing if you want, but you'll have to draw a diagram of what you're wanting to do. Add general dimensions and pipe sizes, as well as appliances and their btu/h load.

On project 1, it sounds like you've got it covered. Don't forget to use pipe dope, not teflon tape. It would also be wise to get an air gauge from a plumbing supply company that you can put on the pipe to facilitate an air test to check for leaks. Leak checking with the 1/2psi gas pressure is not adequate or safe. An air test is required by code as well. Just be sure to shut off the valves at the appliances before pumping air into the line. A 15 minute 10psi test is the norm.

Don't worry about air in the line when you're done. You'll purge the bulk of it when re-lighting the water heater pilot light. Either way, it will bleed off and does not present a hazard.

You also need to get a plumbing permit for this sort of work.

Clutchcargo 11-29-2008 08:48 AM

I looked for the code on friction head and you're correct. No surprise that you know what you're talking about but I had to check anyway.
The chart in Appendix A "TABLE A.2.2" In the International Fuel Gas Code is for informational purposes only. 10 elbows on 1" black pipe can add the equivalent of 26' to the overall pipe length.

Termite 11-29-2008 01:10 PM

Agreed, but the appendices are not part of the code unless specifically adopted. For most practical purposes, you can ignore them unless the city you're working in has adopted them.

Tukeeman 11-29-2008 05:25 PM

Thanks for the replies. So, now I understand that to estimate BTU I need to measure the pipe length to my farthest appliance (the BBQ) from the meter, not the straight linear distance. And I should use the 1/2 inch pipe size for the estimate even though over half of the pipe length is 1.25 inch pipe.

I have seen the recommendation for pipe dope over teflon many times at this site. Odd, because here in Arizona, I have only seen the teflon tape, never the dope. Of course I haven't seen that many installations, but my home, neighbors, friends and the 2 remodel homes I did a few years back all had the tape. You do have to use a lot of tape though, twice what you use for pvc connections, and that is why the dope may be better.

Clutchcargo 11-29-2008 06:11 PM

This site does a pretty good job of explaining pipe sizing:
http://www.propane-generators.com/natural-gas-chart.htm

Termite 11-29-2008 06:54 PM

Quote:

Originally Posted by Tukeeman (Post 191531)
Thanks for the replies. So, now I understand that to estimate BTU I need to measure the pipe length to my farthest appliance (the BBQ) from the meter, not the straight linear distance. And I should use the 1/2 inch pipe size for the estimate even though over half of the pipe length is 1.25 inch pipe.

Right, measure from the BBQ to the meter along the direction of the pipe, not as the crow flies.

Please clarify the 2nd half of this...The pipe from the BBQ is 1-1/4" and then reduces down to 1/2"? Are there other appliances that are fed off the 1-1/4" before it reduces down?

handyman78 11-29-2008 06:55 PM

1 Attachment(s)
Quote:

Originally Posted by Tukeeman (Post 191531)
I have seen the recommendation for pipe dope over teflon many times at this site. Odd, because here in Arizona, I have only seen the teflon tape, never the dope. Of course I haven't seen that many installations, but my home, neighbors, friends and the 2 remodel homes I did a few years back all had the tape. You do have to use a lot of tape though, twice what you use for pvc connections, and that is why the dope may be better.

There is teflon tape specifically for use and AGA & UL approved in gas situations- it is yellow in color (easy for inspection identification), much thicker and more expensive than dope for the gas lines.

Termite 11-30-2008 12:10 AM

Never knew about the yellow tape! I've inspected thousands of homes and hundreds of commercial buildings, and have never seen that used before! Maybe it isn't available around here.

I'd advocate using pipe dope or the yellow tape, but never the white teflon tape...Not on gas!

Tukeeman 11-30-2008 10:02 PM

Yes, the yellow teflon tape! Well I completed Project 1 in less than 60 minutes. I now have a stub at the tee in the garage. Removed all of the pipe that fed the laundry room, took the longer pieces to home depot and had them cut and thread to size for the BBQ run.

Oh there was a casualty. A section of the pipe was hidden behind a small garage cabinet. I thought I could just "dislodge" the cabinet from the wall , remove the pipe, and then reattach the cabinet. No such luck. The whole thing was "glued" together and to the wall with 1/2 inch staples, a lot of them! Well the cabinet fell apart and it's on the sidewalk for bulk trash day next week.

handyman78 12-01-2008 07:53 AM

Quote:

Originally Posted by thekctermite (Post 191636)
Never knew about the yellow tape! I've inspected thousands of homes and hundreds of commercial buildings, and have never seen that used before! Maybe it isn't available around here.

I'd advocate using pipe dope or the yellow tape, but never the white teflon tape...Not on gas!

I would think it is not used commercially due to the availability and economy of pipe dope but it is easily obtained at our PA, NJ etc. Lowes and HDs. Oatey and some others make it.


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