Gas Service Line size ?

[Golestan]

Hello,
I am trying to come up with a service gas line size for a shell building 12000 sf. It will have 6 tenants (Doctors offices, and general office type occupancy). I don't think there will any restaurants going in there. Location is in Dallas, TX, so I am estimating a max 40 btuh/sf for heating (total of 480,000 btuh). There may be some gas use for water heating by some of the tenants. The main line is about 600 ft away. Will 2 inch poly gas main at 4 once be sufficient or should it be at 5 psi pressure.
Any advise...?

Regards,

 

[willard3]

2" dia pipe will do it at 1 psig or more at the main.

It would also be helpful to find out what pressure is required at the gas devices in the buliding....some gas trains have high pressure drop.

 

[joejoedancer]

the international fuel gas code has an appendix section that has an excellent example problem illustrating the correct way to size gas lines based on effective length of piping, inlet pressure and allowable pressure drop.