"In such case, flange will remain leakproof ?"

Hmmm...

Adequate flange design is only one small waypoint on the path to leak-free integrity. I believe that you have a long way to go. Good luck in your journey!

Per TEMA standard, there is a max. recommended bolt spacing B_max = 2 d B + 6 t / (m + 0.5), and there is a min. bolt spacing depends on the bolt size (see the following part of Table D-5 of TEMA).

And the flange will remain leakproof if you kept your bolt spacing between the min. and max. values as stated by the TEMA code.

" And the flange will remain leakproof if you kept your bolt spacing between the min. and max. values as stated by the TEMA code. "

What about:

• bolt specs??
• gasket specs??
• assembly procedures??
• QA control??

Just because a flange has been designed properly does not ensure leak-free integrity of the joint!

You are right BoltIntegrity.

And I'd like to add that while we proceed a design calculations for a flange, as per ASME code in conjunction with TEMA, these calculations -at the same time- have to cover the design of stud bolts, nuts and gaskets. And all flange dimensions and thickness will be affected by (in addition to design pressure and design temperature) size (width and thickness), type and material of gasket. Also the number and size of stud bolts will be depends on the type of bolt material and its allowable tensile strength at design temp. and so on.

And the ASME code states that the flange thickness and its dimensions with bolts and gaskets have to be calculated at two scenarios called gasket condition and design condition and you will select the results with the greater dimensions to withstand the worst condition. (The design calculation will be printed out through 10 pages at least per flange to cover the design of all prescribed items).