Slip on flange B16.5 Code compliance with vent hole

[sugumar99]

we are facing a problem that, On process tank Designed with API 650, the nozzle flanges are having SO flanges, with vent hole drilled before installation, now Questioned for the code compliance of B16.5 as the drilling of 3mm vent hole on the hub is contradictory to B16.5 Interpretation 2-9 dated june 22,1990, can any one help

 

[JoeTank]

I don't know much about the details of B16.5, but I do know that API-650 does not require the drilling of a vent hole in slip-on flanges. It is often done if the flange is part of a PWHT assembly though.

Joe Tank