Flange Boltings.

[Frank1344]

Hello and Good Day,

I am working on a power plant project (ASME B31.1), and the client is asking to use High Strength Stainless Steel Boltings (SA-453) for all raised face welding neck Stainless Steel flanges and spiral wound gaskets.

My problem: Table 112 of ASME B31.1, as per my understanding allows to use other high strength boltings grades as well as SA 453 Stainless Steel, see Note 4.

Then my conclusion is what the Client is asking is on top of the code requirements and we can discuss the matter and convince them to use other materials and grades as per Note 4.

FYI, this is my first power plant project involvement, please take it easy on me.

Now the question may arise: why don't just do as per Client's spec? Then we need to revise our piping material spec. (line classes) and add them to design software spec data base.

I would really appreciate any comment on this subject.

Yours,
Frank

 

[RVAmeche]

In my experience with consulting engineering, you typically use the Client spec unless there's reason not to or they don't have a suitable spec.

If their spec is acceptable and not insanely more expensive than your company's normal spec...I'd say just use it. It may be something like they prefer one material of bolts to make spares easier to maintain or something.

 

[Frank1344]

RVAmeche,
Thanks for the reply.
I am on the Vendor side and not EPC.
That's an easy fix to my problem.
My question is mostly on the technical side and need an opinion on my understanding of bolting requirements as per B31.1.
Is this Client asking for something beyond code requirements or is he right?

 

[davefitz]

Please note that if the operating or design temrperature is above about 1000F then some high strenght high temperature bolting materials may experience corrosion cracking associated with the combination of bolting lubricant and steam- you may wich to have a metallurgist review the particular application and may require use of lubricant that does not use sulphur or other elements that can advance hgiht temperature cracking.

"...when logic, and proportion, have fallen, sloppy dead..." Grace Slick

 

[M Younes]

As maintenance Engineer can some body elaborate on when to use Torqueing Or Tensioner for Flange tightenings