# Those that run Natural Gas - What are your service specs? Pressure and meter capacity?



## FlyFisher (Jun 30, 2018)

All, 

I am running through the numbers on Natural Gas here. Below is a synopsis of what I am looking at:


Current meter capacity = 275 CFH
Conversion between CFH and BTU - 1 CFH = 1000 BTU (roughly)
Additional consumption for generator, high estimate - 300,000 BTU
Primary gas appliance consumption (very high estimate on range/oven) - 224,000 BTU
Total gas consumption appliances + generator, high estimate - 524,000 BTU
Conversion of BTU to CFH - 524,000 BTU/1000 BTU/CFH = *524 CFH *

I am assuming our pressure is around 14" WC. That is the spec on appliances (water heater/furnace) and the only regulator is that on the pipe from the utility feed before the meter. 

What are your gas specs - if you have a sizable generator (15-40kw) installed? Does anyone have a meter that is at least 524 CFH and operates at 14" WC (1/2 PSI)? Or does your system run at 2psi and covers at least 524 CFH?


----------



## iowagold (Jan 22, 2020)

you are better off on residential and a larger gen set to do the 2 psi thing and regulated down at the gen set and all of the gas appliances point of use...
total pain but it is a way to get it done on small lines!
i would also add in an earth quake device valve on the main feed....
it is a high volume system at any rate...

make sure to do a leak test and line inspection on any system upgrades!!
old rusty pipe needs to be replaced.

a million btu meter is the commercial here and is 2 inch line.
that is used at most small restaurants.

and higher numbers in btu at the larger places.... i have seen 4 inch gas line in to some places!
WOW! big stuff! for small locations.

yea the pressure thing is always a challenge on any hvac or gas tech!
i always use a good known pressure meter and check every location before i start work...
just to make sure it is on spec as well as knowing what equipment is used on the regulators...
and tag the pipes as well! mark the pressure and flow with the proper arrows decals.
we started that back in 2000 on the larger systems.


----------



## Browse Deweb (Jan 16, 2021)

Don't know if this is helpful, but my meter at the house is only 250 CFH feeding a gas boiler, water heater, cooktop, dryer and BBQ. When the previous owners added a 335k BTU pool heater, they ran a high pressure 75 FT line from before the gas meter & regulator at the house to the pool area and added another regulator and 400 CFH meter back there. Then they ran a 1.25" line off the meter to the pool heater, stepping down to 3/4" with a valve just outside the heater. We receive two separate bills from the gas company, one for each meter. It's good to know how much money we waste on heating the pool.


----------



## drmerdp (Apr 10, 2018)

Natural gas is 7” water column. Propane is 11-14” water column.


----------



## FlyFisher (Jun 30, 2018)

A bit more information:
- The gas service we have is 7" WC and up to 400,000BTU. 

Now I am really curious. The regulators I have are said to run at 14" WC or so. 7" is 1/2 that. Can we get by with 7" WC? Or will we have to get to 14" WC?

If we upgrade the service pressure the next up is 2psi. From that we could step down to the 14" WC. However, that throws a bit of a wrench in the works for the rest of the house appliances - we would have to step down the pressure for the house also. Do we need to go down to 7" or could we make everything 14" WC? 

The water heater spec is 5-14" WC supply so 14" would be on the high end for it. I am not sure on the furnace specs, other than it is an 80k BTU furnace. The specs are given by the model code and only the heat is spec'd. As to the range/oven - I would have to do some more digging as I can't find any numbers on it right off hand. 

The next flow upgrade is 900k BTU. That does not include a pressure upgrade - it can run at the same 7" WC. However, my earlier question is still valid - if 7" WC is going to cut it or if we need 14". If we need 14" WC it would appear the only way to get there is a pressure upgrade and step-down reg.


----------



## FlyFisher (Jun 30, 2018)

As an aside, the other thread I have on entertaining the idea of a built in unit - the Cummins RS25 (discussed in that thread) has a natural gas spec of 6-14" WC. So the 7" WC service we have would fall in line with that spec. So that makes me a bit more comfortable and confident that the 7" WC we have will work for what I am doing currently - but I am open to comments and discussion.


----------



## ajnuzzi (12 mo ago)

My meter is 275cfh 6-8"wc

I am currently running a 22hp vtwin 12kw gen, 199k btu tankless water heater, 100k btu furnace, stove and clothes dryer. I have tried running every hot water faucet/shower, turned on the heat, the generator, stove and dryer all at the same time with no hiccups. Surprising since all those appliances easily exceed 275cfh. I do have an order in with the gas company to increase my meter, and they also have to increase my main line from 1/2" to 3/4". From what I've gathered the meter ratings are extremely conservative. If the gas company never comes out and upgrades my meter/line I won't even care. First off, chances of me running EVERYTHING at max capacity like I did for the test are slim to none. Secondly, I think my current set up can support it, but I will let the gas co upgrade if they ever come through


----------



## sdowney717 (12 mo ago)

ajnuzzi said:


> My meter is 275cfh 6-8"wc
> 
> I am currently running a 22hp vtwin 12kw gen, 199k btu tankless water heater, 100k btu furnace, stove and clothes dryer. I have tried running every hot water faucet/shower, turned on the heat, the generator, stove and dryer all at the same time with no hiccups. Surprising since all those appliances easily exceed 275cfh. I do have an order in with the gas company to increase my meter, and they also have to increase my main line from 1/2" to 3/4". From what I've gathered the meter ratings are extremely conservative. If the gas company never comes out and upgrades my meter/line I won't even care. First off, chances of me running EVERYTHING at max capacity like I did for the test are slim to none. Secondly, I think my current set up can support it, but I will let the gas co upgrade if they ever come through


Curious about your incoming gas line, is it old? I had a gas employee come by and he was walking the neighborhood lines to everyone's meters with a sniffer. He said he found no leaks, but the steel pipes can rust. My area was constructed in the early 70's

I think my input pipe is also 1/2" and dont have any idea of pressures or volume, but likely is 7".
I suppose you can measure the incoming pipe diameter to know the size where it exits the ground?
And I suppose the line size is the same back to some large gas supply line along the street?


----------



## sdowney717 (12 mo ago)

Black iron steel pipe unions are universally approved for natural gas.





Union fittings used on Natural gas line - Mechanical engineering general discussion - Eng-Tips


I am gathering information before extending gas line to a pool heater. Using black iron pipe, is there a specific union fitting made expressly for natural gas?




www.eng-tips.com




Although I would paint the outside of it and maybe also smear on a coat of marine grease
Copper is in some places and is not allowed in others due to corrosion, due to what is flowing in the natural gas.





Best pipe for natural gas lines: Copper vs. steel, plastic, CSST, etc.


Copper for natural gas pipes? Or steel, plastic, CSST, etc. How long does it take for natural gas to corrode pipes? Code issues.



www.finishing.com




.

SS should be ok too. $17 for 3/4" and you know this is for temporary use too. You would turn off the brass ball valve at the meter.









Amazon.com: Avanty Stainless Steel 304 Cast Pipe Fitting, Union, 3/4" NPT Female : Industrial & Scientific


Buy Avanty Stainless Steel 304 Cast Pipe Fitting, Union, 3/4" NPT Female: Pipe Fittings - Amazon.com ✓ FREE DELIVERY possible on eligible purchases



www.amazon.com


----------

