Just a question.

Why do you need to calculate the thickness for a standard piping item that already exists?

The thickness of a 28" (DN 700) 150# RF Blind Flange is 2.81" (71.374mm). This information is available from Flange makers and Flange Suppliers.

If you have a Blind Flange custom made to a different dimension then it will cost much, much more and unless the maker is qualified to the proper Codes then you may be in violation of the applicable Piping Code (i.e.: ASME B31.3, etc.).

I agree PennPiper,

If you have a standard flange (or blind) size and its class (rating), you can obtain all its dimensions from the standard/code you follow up.

Whatever, if you like to calculate the blind flange thickness, please refer to the following CR4 Thread : can you tell me thickness calcu........

Dear Guest,

Also, you can see the CR4 Thread Hydro Testing and Calculating Blind Thickness

If you go here:

http://www.weldingunits.com/downloads/disks.php

You can download a copy of Flange Data System. From here you can get information on a wide range of flanges, including all the dimensions you would need and more.