Procedure 3-3 Design of Blind Flanges with Openings

Procedure 3-3 Design of Blind Flanges with Openings [1,4] 

Reinforcement is only required for operating conditions not bolt up. 

Option 1—No additional reinforcement is required if flange thickness is greater than 1.414 to. 

Option 2—If opening exceeds one-half the nominal flange diameter, the flange may be computed as an optional-type reducing flange. 

Option 3—No additional reinforcement is required if to is calculated substituting 0.6 for 0.3 in the equation for to (doubling of c value). 

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