Opening in a blind flange 1

[twinbrooks]

Hello, there:

My question is:
An existing 18" line (Sch. 10. A53 Gr. B, class 150 flange rating, operating 300 psig and 200F) ended with a blind flange. A proposal is to open a hole in the blind flange (during shut down time) and connect to a 8" pipe line.

Please help, which code should follow to check whether this opening is safe from stress point of view?

Your advice is appreciate

 

[eliebl]

Please RUN.

Class 150 flanges (Group 1.1) are rated for a maximum of 285 PSI at 100F and 260 PSI at 200F.

Please check the piping code you are using as to the method for calculating that opening. Table 6 (or F6) in ASME B16.5 lists the size of opening that can be put in a blind flange without changing to a hubbed reducing flange.

EJL

 

[TBP]

To expand a bit on eliebl's posting, is the 300 PSIG @ 200*F the operating point, or the safety/relief valve setting? If you're not using the safety/relief valve setting, then it's just that much worse.

 

[JohnBreen]

........also, read ASME B31.3, paragraphs 304.4 (including its sub-paragraphs) and 304.5. This will take you to ASME B&PV Code, UG-34.. You should really consider using a B16.9 reducer.

Regards, John.