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Old 01-03-2010, 09:07 PM   #21
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Didn't know of such a beast. I wonder if it's approved in UPC country. Will find out tomorrow. Wait a minute, what's the point of a vent if you put a throttling device in it?

I'm comfortable with you, Adam
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Old 01-03-2010, 09:23 PM   #22
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What's wrong with the sizing chart in NFPA 54?

It covers all the common pressure ranges. I have used it on jobs ranging from 1/2" threaded to 8 welded.

I disagree on bumping the pressure and installing regs. I think were piping diameter can be increased, pressure should be kept low.

Regs. are pricey. I can run a lot of larger diam pipe as opposed to buying 30 regs and venting them.
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Old 01-03-2010, 09:28 PM   #23
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Quote:
Originally Posted by ILPlumber View Post
What's wrong with the sizing chart in NFPA 54?

It covers all the common pressure ranges. I have used it on jobs ranging from 1/2" threaded to 8 welded.

I disagree on bumping the pressure and installing regs. I think were piping diameter can be increased, pressure should be kept low.

Regs. are pricey. I can run a lot of larger diam pipe as opposed to buying 30 regs and venting them.
I know that's right. When wardflex came out, the gas co. was pushing it. We did a detention center w/medium pressure. The wardflex was free but by the time I installed all the regs. and vents it was a loosing proposition.

Last edited by SlickRick; 01-03-2010 at 09:30 PM.. Reason: quote button malfunction
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Old 01-03-2010, 09:49 PM   #24
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Quote:
Originally Posted by ILPlumber View Post
What's wrong with the sizing chart in NFPA 54?

It covers all the common pressure ranges. I have used it on jobs ranging from 1/2" threaded to 8 welded.

I disagree on bumping the pressure and installing regs. I think were piping diameter can be increased, pressure should be kept low.

Regs. are pricey. I can run a lot of larger diam pipe as opposed to buying 30 regs and venting them.
Regs have their place no doubt. But,other than the risk factor of a potential leak on a higher pressure gas line, why do you like to run the bigger line?

I got into using regs on gas lines lately do to the big BOOM in tankless sales here. This is due to the generous rebates our local city is giving out for them.
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Old 01-03-2010, 09:59 PM   #25
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I was able to cut the price in half on a long roof job that two other contractors failed to consider medium pressure.Took 200' feet of 4" and cut it down to 1-1/4".The big gas draw was at the end of the run.The gas co. swapped out the meter for free.
Having General Motors buy the regs with the equipment helped me out.I told them it would be a lot less weight on the roof to move them in the proper direction.
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Old 01-03-2010, 10:25 PM   #26
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I was able to cut the price in half on a long roof job that two other contractors failed to consider medium pressure.Took 200' feet of 4" and cut it down to 1-1/4".The big gas draw was at the end of the run.The gas co. swapped out the meter for free.
Having General Motors buy the regs with the equipment helped me out.I told them it would be a lot less weight on the roof to move them in the proper direction.
Who holds the liability when the reg fails?

How comfortable are you with leaving a gas line w/ 28" or more of water column exposed on a roof where it can get damaged by any roofer, handyman, satelite installer , whatever?

I would prefer to minimize the pressure at the lowest possible point, at 2 PSI a gas leak blowing wide open will blow the building up in no time if ignited, and if it is near a vent stack it takes little atmospheric pressure to draw it into the building.
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Old 01-03-2010, 11:00 PM   #27
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Who holds the liability when the reg fails?

How comfortable are you with leaving a gas line w/ 28" or more of water column exposed on a roof where it can get damaged by any roofer, handyman, satelite installer , whatever?

I would prefer to minimize the pressure at the lowest possible point, at 2 PSI a gas leak blowing wide open will blow the building up in no time if ignited, and if it is near a vent stack it takes little atmospheric pressure to draw it into the building.
The regs belong to them.That's another beauty of it.
No,I do not have a problem with medium pressure gas contained inside a schedule 40 steel pipe...None.
It's some pretty tough stuff Spider.I'll stick with it.I work with it on a regular basis.We got some BIIIG areas to get gas around to(properties and structures).Really helps out when the meter is on the street on the city's side of the gate and the house is 300' up the driveway.Hate to see someone have to run 4" through the house to the kitchen(small exaggeration).

I did the penthouse on one Utah's highrises he's a witness on.He saw it.It has some 50 1/2" gas services on P1 serving all units going all the way up 23 floors to where the csst vented regulator is installed in the penthouse.
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Old 01-04-2010, 02:12 AM   #28
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Well, I asked about why there was no medium to high pressure gas systems around here and the inspector simply said, this is earth quake country and the powers that be didn't want high pressure gas running in peoples homes. An earth quake feels sorta like sitting down on a water bed for about 5 to 10 seconds. When the Northridge quake hit, Balboa Blvd whis is a 6 lane regular road was split open and a high pressure line blew apart and had flame shooting in the air. The water main also let go...it was pretty bad and I grew up about 5 minutes away from that. They left tha gas on, until Clinton could come and see it. He got out of his limo, waved to all of us with a big smile and then left. Fing tard.

If you're so inclined to know why we have SO many building codes and insane safety codes in place in the UPC and other trades' code, you can read what I lived through. This one did not feel like sitting on a water bed. It felt like sitting on a dunk tank bench and some kid hitting the bulls eye, with no water in the tank


http://www.ci.la.ca.us/lafd/eq.htm

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Also significant were the ruptures of a large natural gas main and a water main at the intersection of Balboa and Rinaldi. These ruptures occurred immediately following the earthquake.
Subsequent to the rupture, the natural gas main ignited, and five single family homes were consumed in the ensuing fire.
Area residents were evacuated by arriving firefighters and no serious injuries were reported.
http://scec.gps.caltech.edu/recenteqs.html
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Old 01-04-2010, 12:52 PM   #29
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Did some homework on the vent limiting device.
Per UPC
C. Uniform Plumbing Code IAPMO/ANSI UPCI-2003 section "1209.7.5 Venting (A) Line Gas Pressure Regulators.
(1) An independent vent to the outside of the building, sized in accordance with manufacturer's instructions, shall be provided where the location of a regulator is such that a ruptured diaphragm will cause a hazard. Where there is more than one regulator at a location, each regulator shall have a separate vent to the outside, or if approved by the Authority Having Jurisdiction, the vent lines shall be permitted to be manifolded in accordance with accepted engineering practices to minimize back pressure in the event of diaphragm failure. [See NFPA 54:5.9.7] for information of properly locating the vent.) Materials for vent pipes shall be in accordance with Section 1209.5.
Exception: A regulator and vent-limiting means combination listed as complying with ANSI Z21.80 / CSA 6.22 Standard for Line Pressure Regulators shall be permitted to be used without a vent to the outdoors.

http://www.maxitrol.com/ventlimiter.html
Seems they are limited in their BTU load. As explained to me, they are generally used in a single appliance application (not whole house).

The danger of a sub regulator going bad is no greater than that for the regulator supplied by the gas utility. Worst case scenario is a ruined appliance gas valve.

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Old 01-04-2010, 01:23 PM   #30
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Using UPC tables @.60 specific gravity and 1100 btu per cubic foot this is our basic for natural gas . our chart is in 10 ft increments so 70 foot alows 490 cfh or 539000 btu on 1 1/4 pipe. As far as medium presure with a regulator at the appliance not very common here Its done on some jobs it would take a little research . Not a great saving on a job of this caliber.
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