Dear Experts,

We are carry out Flange Check thru Flange Module from CAESARII, we faced the 6" & 8 " 150 # Flanges SO - Failed in bolting stresses even with 0 Load & 0 Moments.

These are failed in EQUIVALENT PRESSURE CHECK & DETAILED
ASME Sec 8 Div 1 both methods by CAESAR.

Can anybody throw light on this issue?

1) Is there any factors need to consider additional for this type of flanges?

2)How to make agree to client when to issue the reports of such type of cases?

Regards
SND

Dear Richard Sir,

Can you please short out or suggest us ASAP?

Regards
SND

Many ANSI flanges fail the ASME Sect VIII Div 1 stress check. These flanges are "grandfathered" as "ok" because they are ANSI flanges.

Richard,

what is the solution for this.. how to report to client..
Ramaswami.P

Dear Richard sir

Thanks for ur reply,

However, it is difficult to convince the client for this matter,I agree these are ANSI Flanges, & run since a long time the same in major refineries / plants but if with 0 Load & 0 Moments in Bolt Seating Stresses -- FAILED.

This is somewhat mismatch in either code databases for diamention,
stresses tables of flanges,gaskets & Bolts
Or, my understanding?

Even though,I tried for Weldneck Flanges, the same result.

Regards
SND

If you do an ASME VIII Div 1 or Div 2 flange calc you will probably find tha the stresses are ok in the operating condition, but fail the bolt-up limits.

If acceptable in process terms, changing the gasket type (to reduce y and m values) can help.

This is a common "problem" which has been addressed many times in this forum. As Rich Ay has already alluded to, there are thousands of similar joints in successful service worldwide, so it might just be a little dischord between Codes.

Thanks MoverZ.

I know by using Kemprofile Gasket or other type of gasket where value of m & Y will change from vendor rather than using Code ASME B 16.5 & ASME B 16.20, this problem can solved easily, but it depends on client to client.
Client shall have always authority to ask any technical reason.

Dear ,We had also carried out several time the same as you mentioned, but what I appeal there should be have some technical reason to explain Client or Code's explanation note for this matter.

This matter almost every one has to face where 150# Flanges of 6" & 8" comes to check for Flange Leakage.

Dear Richard sir, Have you come across this problem before from any one? What is your suggestion in addition to your previous one.

Regards
SND.

Doing an ASME VIII Div 1 or Div 2 flange calculation you would find that the stresses are ok with p=0.01psi as operating condition, but fail the bolt-up limits...
IMO these results demonstrate the limits of calculation method.