Gas Piping

Mpj

I'm looking at a job I need to install a gas fired pool heater. The heater is about 35' away from the house that piping will be underground. I need to pipe from the meter to where it will meet the outside underground piping approx. 22'.

On table 6.2(a) of NFPA54 at 60' i need to use 1.25" blk pipe to 400,000 BTU's.

on table 6.2(f) for poly pipe I need 1" at 30.

My question is can I go from 1.25" blk after the first 22' and then go to 1" poly from there?(I have an 50" roll in my shop)

Or just keep it 1.25" which I normally would do.

Tim McElwain

Assuming the 1 1/4" is

sized correctly and corrosion protected and the meter is sized correctly I would go with 1 1/4" all the way.

Mpj

Gas pipe

Thanks for your reply Tim. That is what I was going to do. I just had a debate with another plumber friend of mine about dropping pipe sizes on long runs.

I thought poly pipe was corrosion protected, if not what would you recommend?

Henry

Piping

You can steel pipe above ground and poly or copper below ground with a tracer above it. A valve is required before you go underground and once you are above. For such a short run, you can run CSST in a drainage pipe that is sealed at both ends. It is much cheaper.