Dear All,
Why there are difference between codes?
B31.3 have higher allowable stress than B31.1
B31.3 does not use SIF for reducers.
Like this many differences are there between codes published by same group.
In same way there will be difference between codes published by different groups(ASME, BS, IS, etc).
All codes are tends to have a safe design inorder to protect human life.
Why cant we follow a same code atleast within a group(ASME 31.1 AND 31.3). Eventhough the application is different, the design method is same. Then why there is difference between B31.1 and B31.3
Can any one clear my doubt...

Regards,
Kparthy

kparthy,

this might help?

http://65.57.255.42/ubbthreads/ubbthreads.php?ubb=showflat&Main=2974&Number=12757#Post12757

In my opinion, they're area is diffrent. Power plant and Chemical plant are not same at all.

Dear MK,
Thanks for your reply.
That post seems like discussion about unit conversion between codes and also use of hot or cold moduls of elasticity in calculating stress. But i feel i dint get the answer there.
As you said the application is different, i too following it as given in code.
In the training manual given by COADE, they had mentioned the difference between the two code, says that the factor of safety used for calculating allowable stress is different.
My doubt is this, why they use different FOS?
Also there are difference in SIF values for some fittings between these code . Generally why there are difference like this within the same group code(ASME).

Regards
Kparthy

A failure in a power plant could affect the power grid outside the plant. A failure in a process plant is considered a loss - inside the fence - to the owner alone. Things are not that simple but that's why B31.1 is more conservative than B31.3.