Gas piping routing options & best meter location

[Tuttles Revenge]

I don't envy you in that installation.. We use Megapress so that would be an hour or 2 installation.

Lifting the wrenches in that position will be tough too.. make a cheater from a lenght of pipe with an elbow on the end that will go over the wrench. You might get a few degrees extra umph out of it.

 

[Makemenuconfig]

Got it done. It was better than I expected, but still not fun. Surprisingly laying on your back right next to the pipe gives you decent leverage. Used the 18" wrench.

Threads on one of the couplings or pipes must have not been cut perfectly straight at the factory, had maybe a 1 degree angle on it. I'm positive it wasn't cross threaded since everything was fairly easy to hand-tighten many turns. Used a string line to make sure everything was lined up and supported in-line.

Held 6PSI for 48 hours, ending with 6.5 PSI which was in line with my temperature measurements. Inspection later this week.

Pay no attention to the ugly patchwork OSB from a fireplace I removed, that will get cleaned up eventually. Thanks again!

 

[Sponsor]

 

[Tuttles Revenge]

Very cool! I don't see a lot of 45's in gas work, I don't think most people like trying to measure for those.

 

[Jeff H Young]

Nice Clean work Good Job! 45s kind of pain to work with I truthfuly avoid them typicaly dont use them at all except occasionaly. Not a lot to gain typicaly but respect those trying to do clean work. and glad system is holding, I like threaded pipe and loath that flex csst .

 

[Makemenuconfig]

Thanks! Somehow I like working with 45's.

The inspector was very brief and passed me, then the gas co. came out to turn the meter back on. The tech said he wished more contractors did work like this, he liked my use of split ring hangers on the wall and the escutcheon I made on the outside. He had me add a tee and valve outside to bleed the main line, and got gas back on.

The tech suggested I put a ball valve at the meter outlet when I have the new meter installed so I can turn the gas off and on myself. I mentioned to him I was thinking of getting a seismic shutoff valve also, he seemed negative to it. Said they were the bane of his existence (nuisance trips) and induce a pressure drop. I like the peace of mind (since it's my own house in the Seattle area), but now I'm second guessing.

I was going to use a 1-1/4" seismic valve because that will be the meter outlet size. The datasheet for it says it can flow 1,103 CFH with a 0.1" WC pressure drop which seemed minimal. It would require 1-2' of 1-1/4" at the outlet before upsizing to 2". Would any of you put one on your own house?

 

[wwhitney]

Would any of you put one on your own house?

Absolutely. The techs comments are based on his interactions with uninformed homeowners. You won't have any of the difficulties he mentioned.

Cheers, Wayne

 

[Tuttles Revenge]

We recently were installing a seismic shut off for a customer and the contractor replacing the gas mains in the street mentioned that they were pointless because a gas restricting system was in place in the new mains. I've never been able to verify that info so we continue to install them and inform the customer on how to reset them if they trip for whatever reason. I don't think they trip very often. But maybe I'm not the one getting the call in most cases. I personally still recommend them to customers.

I would figure that with the size of line you have that PSE would have provided a meter that has shut off valves on each side of the meter.

 

[Jeff H Young]

makemenuconfig, I'm not that big a fan of seismic valve . I think Los Angeles county (or city) requires them when a house is sold if it doesn't have one. very easy to reset . I've installed a small number perhaps a dozen . Totally a personal preference and Have no disagreement to one feeling a little safer with it.
That was awesomely clean job, Unistrut in attic, the hangars, pretty much just use p tape and 2 hole straps. none of that flexy CSST crap in there!
The T outside at meter has uses in case the gas supply is interrupted they can feed your house with gas temporary through the tee I spose pressure test as well. I typically just stub out the house with a nipple and a cap and gas company puts the tee on and they never put a valve on customer side of meter and I never do either. I just use their valve. different places operate differently a mere suggestion of a valve wouldn't cause me to add one only if I had a major run taking off like for a pool or something. The tee I would have put if I was hooking up meter because that's how So Ca Gas rolls.
BTW.. isn't the gas shutoff easily accessible? yes you need a shut off but who cares which side its on

 

[Makemenuconfig]

BTW.. isn't the gas shutoff easily accessible? yes you need a shut off but who cares which side its on

Sure is. PSE is very clear you can shut off your gas in emergency or for new work, but you HAVE TO call them to turn it back on otherwise you might blow something up or whatever. Since this is the first step in a large addition, the 2" line will be extended into the addition, and I'll install a backup generator later. Not an excuse not to pressure test or pull permit, but allows me to not keep bugging them and waiting until a tech can come out to restore service.

Not sure if they are installing an outlet side valve and/or an excess flow valve, I can ask my project manager. Still, it will be a 1000CFH meter, so would take a lot of flow to trip. An earthquake valve would still have its place in that scenario.

The techs comments are based on his interactions with uninformed homeowners"

Indeed. I figure he's biased since every call he ever gets about one of these valves must be because it isn't working correctly or tripped.

 

[Jeff H Young]

Our gas companies tell us don't turn gas off after an earthquake unless you smell gas many do anyway . So they don't have to relight pilots. Don't know what our official recommendations are but since only 1 in a hundred homes have its own shutoff on customer side of meter . I've never heard of calling them unless its customer that cant /or wont ,doesn't know how.
I think meters are going to smart meters perhaps they get alert if gas is shut down, they don't want you messing with it or they figure you might be jumping the meter for free gas . any way you are doing great I'd proceed however supplier wants.

 

[Tuttles Revenge]

I blew a diaphragm on a 3" meter once.. turned the gas on too fast.

 

[Makemenuconfig]

Hopefully my last question for you all on this project. New meter connection is happening in two weeks.

Meter outlet will be 1-1/4", and main trunk is 2". Code isn't super clear about the amount of acceptable pipe length before upsizing at the meter. I want to install a ball valve and seismic valve before upsizing to the 2" main. This is because a 2" seismic valve costs about 3x as much.

This will induce some amount of pressure loss across the valves, but will it be acceptable? Datasheet says this seismic valve will introduce 0.1" WC drop when flowing 1,100 CFH at this inlet pressure or could be figured as 4' equivalent length. The ball valve is a full-port valve but would introduce some drop too presumably. Since I sized this system with the 0.5" WC drop table I think you'd see worst case 0.6" WC drop at full load.

The gas company rep said he thinks it would be fine but I should check with my plumber (which is me). Figured I'd ask here too. Here's a drawing:

 

[wwhitney]

Pressure drops add, so the thing to do is go back to your design and put in the appropriate length of 1-1/4" pipe in at the beginning, then check everything (possibly using the more exact method I posted near the beginning of this thread). Or ask the installer to adjust your regulator to 7.1" w.c. rather than 7" w.c.

You can also consider using a 1-1/2" seismic valve, upsizing immediately to 1-1/2" at the meter, then to 2" at the seismic valve output. Or depending on the distances, it could be worth using 2" between the meter and the seismic valve. You might also lay things out to facilitate upsizing the seismic valve in the future should you ever have any issues.

Cheers, Wayne

 

[Makemenuconfig]

Math was the key, thanks Wayne.

Using the simplified low pressure Spitzglass formula I calculated the farthest / most sensitive fixture (BBQ) has a total drop (from start of 2" to fixture) of 0.324" WC.

If I want to stay at a total drop of 0.5" WC, then I need this reduced meter portion and valves to be 0.176" WC or less (0.5-0.324=0.176) drop. The same formula says that could be 14' total equivalent length of 1.5" pipe, or 5' of 1.25" pipe. Considering the equivalent length of the seismic valve is by itself 5', 1.25" would have been too small.

Thus, 1.5" is adequate assuming I can do it in less than 14' of pipe which should be no problem. Parts on order.

 

[Jeff H Young]

don't know how to do that math the system I learned for gas systems only had cfh of gas or btu and lengths.
usually piping between meter and entry to building is a few feet tops. I would have expected 1-1/4" adequate . somehow an 1-1/4 meter going to work but a seismic valve going to choke it up? I kind of doubt it. but a little piece of mind I suppose. I'm sure you'll have a perfect system going 1-1/2" no way that won't run well

 

[Makemenuconfig]

I'm sure 1-1/4 would have functioned fine. With a residential system this large, I'm willing to bet it never runs at full capacity in its entire service life. Even if it did and exceeded 0.5" drop, the most sensitive fixture is the BBQ, and dropping below its minimum isn't going to cause a flameout. All the other appliances have a much lower minimum so they would be fine too.

Generally in life, my motto is: if it's worth doing, it's worth over-doing. It was $86 more to do the 1-1/2, vs the 1-1/4. Didn't really think twice about it.