On 2010-07-16, Ca****cher wrote:

Thanks to everyone for the feedback. Clearly, installing a tee from the
existing 1/2-inch line has the potential to starve either the gas range or
water heater if both are operating. So, I'll extend the 1" supply line to
the point where both appliances can be individually attached. Much more
complicated but probably necessary.

Going back to the 1" supply line is the more robust solution for sure.
Then if you want a surefire solution that won't require any calcs, you
would need to run a 3/4" line to your gas range.

But if it that is alot of extra work, you can get an exact answer to
the question of "will teeing off the existing 1/2" line be OK?" What
you would need to provide is a diagram showing all your gas
distribution piping (and the new proposed 1/2" piping) like that in
the PDF Bob found:

http://www.ci.pleasanton.ca.us/pdf/bldg-gaspipe.pdf

The lengths given should include fittings based on their equivalent
lengths, but if it is difficult to tell you could estimate that part
using 2' for each 90 degree bend. Also, if your distribution piping
branches immediately after the meter, you can start diagramming after
that branch point.

With that information I can show you how to calculate the pressure
drops and answer your original question.

Cheers, Wayne