Need a little help on this one. I working on a review/design of a large bore flange for a duct. I'm looking at a hubless slip-on arrangement like an AWWA pattern flange and I'm trying to use the Caesar flange analysis tool to help with checking it out.

I'm having some trouble figuring out which one to use. I think the "Loose Ring" choice looks like the right one graphically. But, when I select it, it still calls for inputs for the hub parameters. The integral ring graphic looks the same as well. Also, when I think of a ring flange, I'm expecting it to refer to a ring type gasket.

I just want to verify that the "Loose Ring" style is the one I want to use in this case. Or, for that matter, if this tool will even review this style of flange.

Hi Ed,

This might interest you:

http://www.copcoltd.com/soft/mecheng02/sof.htm

Regards, John.

Hello Ed,

If your ring flange is attached with a partial penetration groove weld and a fillet weld to the pipe then it can be analyzed either as an integral or as a loose flange. These flanges are known as an optional type of flanges. Refer to ASME Sec. VIII Div. 1, app. 2, Fig.2-4.

It is advantageous to analyze an optional flange as an integral flange as the pipe is considered part of the flange. You can enter the pipe ID as the flange ID.

You can consider the fillet weld at the back of the integral ring flange as a hub. It may reduce your stresses. But, if you do not want to do this then leave the hub dimensions as zero.

CAESAR II should be able to analyze this flange.

I hope this helps.