Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contactus/.
Click here to Find a Contractor in your area.
NG pipe sizing
ChrisJ
Member Posts: 16,074
in Gas Heating
Hi all,
I'm hoping someone can just quickly double check my work here to make sure I'm not being a dope.
These are the sizes I came up with for piping and the incoming line just seems a bit much to me. Am I way off or is this about right?
Supply pressure is 6", although after the meter 5.5" seems more realistic. They give me so much extra to play with..........
Please see the two attached drawings. Hopefully they work.
I'm hoping someone can just quickly double check my work here to make sure I'm not being a dope.
These are the sizes I came up with for piping and the incoming line just seems a bit much to me. Am I way off or is this about right?
Supply pressure is 6", although after the meter 5.5" seems more realistic. They give me so much extra to play with..........
Please see the two attached drawings. Hopefully they work.
Single pipe quasivapor system. Typical operating pressure 0.14  0.43 oz. EcoSteam ES20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
0
Comments

Yes, a bit too much from what I can tell.
Table 128 in the 2009 Uniform Plumbing Code will allow you to run 11/4" schedule 40 pipe and will supply 528 cubic feet a maximum of 60 feet.
Inlet pressure less than 2 psi, with no more than a 0.5" pressure drop.
8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour
Two btu per sq ft for degree difference for a slab1 
@ChrisJ
your good to go. I used low pressure gas chart .05"wc pressure drop0 
Hi Alan,Yes, a bit too much from what I can tell.
Table 128 in the 2009 Uniform Plumbing Code will allow you to run 11/4" schedule 40 pipe and will supply 528 cubic feet a maximum of 60 feet.
Inlet pressure less than 2 psi, with no more than a 0.5" pressure drop.
I came up with 80 feet as the longest run when taking fittings into consideration. But I'm also concerned I did it wrong.
I'd much rather 1 1/4 to be honest.....Single pipe quasivapor system. Typical operating pressure 0.14  0.43 oz. EcoSteam ES20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment0 

P.S. Check with your local gas supplier for density. Here, it's 1,000 BTU's per cubic foot.8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour
Two btu per sq ft for degree difference for a slab0 
I think I had actually asked back in 2011 but I'm not remembering the actual answer. I don't like this getting old stuff....P.S. Check with your local gas supplier for density. Here, it's 1,000 BTU's per cubic foot.
Does the btu content effect what appliances actually flow? I assumed they would still flow the same amount and just deliver slightly less or more based on the content?
Single pipe quasivapor system. Typical operating pressure 0.14  0.43 oz. EcoSteam ES20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment0 
Do you think I could get by with an 1 1/4 on the first section, or too close?EBEBRATTEd said:@ChrisJ
your good to go. I used low pressure gas chart .05"wc pressure drop
Single pipe quasivapor system. Typical operating pressure 0.14  0.43 oz. EcoSteam ES20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment0 
Odds are you won't notice the difference going with 1¼". something like 7080% of the gas lines I come across in the wild are undersized according to the old tables, but only like 1020% of the equipment gives me trouble.
Can you get the 1½" cut & threaded at a big box store? If they get the dies in the right order, they'll usually pull up tight enough.
1 
> @ratio said:
> Odds are you won't notice the difference going with 1¼". something like 7080% of the gas lines I come across in the wild are undersized according to the old tables, but only like 1020% of the equipment gives me trouble.
>
> Can you get the 1½" cut & threaded at a big box store? If they get the dies in the right order, they'll usually pull up tight enough.
I'll be using my 65RTCSingle pipe quasivapor system. Typical operating pressure 0.14  0.43 oz. EcoSteam ES20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment0 
Categories
 All Categories
 85.9K THE MAIN WALL
 3.1K AC, Heat Pumps & Refrigeration
 52 Biomass
 420 Carbon Monoxide Awareness
 78 Chimneys & Flues
 1.9K Domestic Hot Water
 5.2K Gas Heating
 94 Geothermal
 154 IndoorAir Quality
 3.3K Oil Heating
 59 Pipe Deterioration
 884 Plumbing
 5.9K Radiant Heating
 377 Solar
 14.6K Strictly Steam
 3.2K Thermostats and Controls
 51 Water Quality
 40 Industry Classes
 47 Job Opportunities
 17 Recall Announcements