GAS PIPE SIZE

[MasterPlumbersKeymaster]

I have a building needing a gas line .I have a total of 360,ooo btu.The total length of the line is 65 feet.I figure the pipe size to be 1 1/2 inches.Is this correct? Thank You

[SylvanLMPParticipant]

What gas pressure and what is the specific gravity of this gas, is this LPG or natural.

AND what is the heating value of the type of gas your using.

Some natural gases can be as low as 900 BTU per CU ft and some as heigh as 1,200

[SylvanLMPParticipant]

quote:

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Originally posted by [email protected]:
I have a building needing a gas line .I have a total of 360,ooo btu.The total length of the line is 65 feet.I figure the pipe size to be 1 1/2 inches.Is this correct? Thank You

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Ok based on a pressure drop of 0.3 inch water column and 0.6 specific gravity of the gas and a deeveloped lenth of 65 ft you could use an 11/4 pipe so the 11/2 would be fine.

Check with your local gas supplier and building department to be sure.

You are better off slightly over sized in case you add any more appliances later. Good luck

[Frank HiebertParticipant]

I will give you two different scenario’s, both based on natural gas with a specific gravity of .6, but different pressure. I have used a developed length of 70′.

For gas pressure of 7″ to 14″ water column, based on a pressure drop of 1/2″ wc . Schedule 40 pipe, 1 1/4″ will allow you 440,000 btu’s, 1 1/2″ pipe will allow you 659,000 btu’s.

For gas pressures of 2psig, schedule 40 pipe based on a pressure drop of 1 psig. 1/2″ pipe will allow 503,000 btu’s for 70′.

These numbers are based on the Canadian gas code and are here only for an example to you. You should definitly have a lisenced gasfitter correctly size and install this for you, as there are many other variables that will come into play, and codes to follow for the proper installation and testing. Good luck

Frank Hiebert
3rd yr apprentice
Edmonton, Alberta

[SylvanLMPParticipant]

Hi Frank, FYI in NYC any gas pressure exceeding 1/2 PSI is considered High pressure.

[fourth yearParticipant]

In AZ, 3 to 5 pounds is medium pressure. Usually the only time the utility will supply medium pressure to a house is when corrugated stainless tubing is installed for the gs system. And then each appliance has to have a pounds to inches regulator installed.

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