I’m relatively new to properly sizing and installing gas lines. I got trained and certified in using CSST fittings and tracpipe. I have my first real application and wanted to know if anyone out there has experience calculating pipe sizes.
Owner wants to install two NG heaters in large workship. Each unit is 75,000BTU. The workshop is some distance from the house where the NG line comes in. It’s a 1″ Iron pipe feed for the house. I need to tap onto the line at the house where the meter/regulator is. From there I must go 100 to 120 ft to the first heater. From there the distance to the next heater is about 100 to 120 ft.
Using my trusty cheat sheet I see that 1CFH of NG equals 1,000 BTU. If I add up both units I get 150,000 BTU. If I divide that by 1,000 I get 150. THerefore I need a pipe sized to carry a minimum of 150 CFH.
I’m trying to find out what the pressure is in my area. If I assume an 11″ W.C. then my chart tells me that a 3/4″ pipe supplies 131 CFH and a 1″ supplies 237. From that I gather I need a 1″ CSST line. WHich I can do since the line supplying the house is 1″.
But…if I assume the Standard Low Pressure my instructor told me is most common, which is a 6″ W.C. then my chart tells me I need to use a 1.5″ pipe to supply the heaters. That’s not right, or is it?
I’m confused, any help and discernment is welcome.
Replies
Greetings Willie,
This post, in response to your question, will bump the thread through the 'recent discussion' listing again which will increase it's viewing.
Perhaps it will catch someone's attention that can help you with advice.
Cheers
94969.19
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Consider this mostly just another bump....
First though, I think you have to find out what sized meter it is. Here, there are 2 sizes - a 2# (which all my houses get) and then something else....