If the asme 16.5/16.47 standard Blind flange having openings, Can we need to pass the calculation of appendix-2 or we do not need this to comply ?

Check reinforcement requirements...

As per my understanding if you are modifying the std. flange ( with openings etc.) then you need to design the flange per App. 2 and then perform reinforcement check on it.

Dear ketan daraji,

I cannot understand your query, standard blind flange do not have any opening (except BCD) in it, if you are having one then it must not be a standard flange and you need to do the appendix 2 calculation,


Regards,
Hitesh Pawar

Dear all,

This discussion is relevant to my reply posted to Mr. Ketan today about max. opening size (3.5") allowed on std. B16.5 24" blind as example.

Reference can be made to ASME B16.5 : 2003, Table 6.

As long as center opening on blind not larger than sized listed under column 2, 4 and 6 (where hub requirement starts), pressure/temp. rating can still cover the blind. No calculation on reinforcement & thickness will be required.

Notes :
Off-center opening was not shown, may not be covered.
This provision is solely applicable to B16.5 only.
B16.47 : 1996 does not have this provision. Any opening will be considered as modification thus require further calculation on thickness and relevant reinforcement(UG-34/UG-39 etc)

Thank you!

S K Tan