Trying to match an old natural gas table
Posted: Wed Dec 05, 2012 11:12 pm
I was needing to calculate pipe sizes for a 35psi natural gas system and was attempting to use a chart in the 2012 International Fuel Gas Code for pressure over 1.5psi that I hadn't ever used before. To check myself I attempted to get it to match a table from an old gas book for 20psi delivery. It wasn't matching, so I started looking online for a calculator and found yours. Your calculator matches that IFGC chart. So now I'm trying to figure out why your calculator and that chart don't match the old table. The old table shows consistently higher capacities per pipe size. I've attached a scan of that old table. Any ideas? Has the calculation for calculating this changed since the 60s, or am I doing something wrong?
As a check I was looking at 20psi, 2psi drop, 400' of pipe, 2" pipe size. The old table shows that will carry 10,610 cfh. From the calculator it carries about 7,600 cfh. That's nearly a 30% difference.
Thanks
As a check I was looking at 20psi, 2psi drop, 400' of pipe, 2" pipe size. The old table shows that will carry 10,610 cfh. From the calculator it carries about 7,600 cfh. That's nearly a 30% difference.
Thanks