Flange Thickness Calculation

Is this for air handling, at a few-inches-of-water-gauge, or is it for something else at a higher pressure?

If its for a pressure vessel or something from this importance, you must always refer to your local regulations regarding it. All those stuff is standardized, for easy of manufacture, interchangeability with equipment, and safety. For example, according ASME, a general rule for stablishing flanges in pressure vessels for connections is to imagine the cross section of the opening. A cross section like this will show up as a plate with a blank in the middle. So, calculate the area corresponding to this opening, i.e., the opening lengh x thickness, and make a reinforcement flange with the same cross sectional area to be welded in the opening. But, again, according to your problem and local regulations, results may vary.

http://cr4.globalspec.com/thread/33456

Thank you very much.

i'm just arrived to my office few day ago.

my question is not for pressure vessel but for equipment that make pressure 4.6 kPa (inlet 102.6 kPaA and outlet 107.2 kPaA) and gas handle is N2.

Can you give me for some formula and formula's referance?

Thank you very much for your help.