ASME B31.3 EN 13480 Flange Bolting

[John Jones]

Hi Guys,

Recently I am encountering some disputes on flange management and the correct values for tourque, tensioning.

Some people want to go off the gasket rating.

Others want to go off 70% of the yield stress of the bolt.

Other than ASME PCC-2, what are peoples thoughts on this?

 

[dgeesaman]

Wouldn't you need to consider both the bolt strength and the gasket rating?

 

[r6155]

See ASME PCC-1

 

[EdStainless]

You need to know all of those, but which governs will depend on the situation.
I hope that they are in better agreement on the process of how to torque the flange.
That is much more complicated than the load.

 

[John Jones]

Edstainless no they are not. Tensioning vs torque raised its head.

 

[EdStainless]

And the process matters a lot.
I took a one-day course some years ago.
They had an instrumented flange for us to work with.
After 6 hours of going over theory, guidelines, and methods we each got a chance at the fixture.
Only half of the group ended up with results that were considered suitable for long-term service.
The rest would likely leak at start-up or fail prematurely.
Only 2 out of 30 hit the desired values and uniformity right on.