Gasket Selection 1

[Kaadm]

Hello everybody,

A pressure control globe valve made of carbon steel (SCH 160,CS ASTM A106 GRB) has been

severely corroded in a gas plant,this valve is placed in between two pipes (SMLS,ASME B36.10M,

BE END, SCH 160, CS ASTM A106 GRB)assembled by a spiral wound gasket (GSKT SPRL WND ASME

B16.20 ASME B16.5 CL 600,TP304, SS WDG, Graphite Flr,TP 304, SS INR RING,CS OTR RING).

THis valve has been changed by another valve which has the same design only made by Stainless

steel instead of Carbon Steel.

my question is how to connect (gasket type) a pipe made by a Carbon steel with Stsainless

steel valve?

i believe that the gasket mentioned above is not suitable for this assemblage due to the

electrochemical potential caused by contactig the inner ring (SS)to a Pipe flange made by (CS).

Service:Corrosive Hydrocarbon

any help would be appreciate,

Best regards,

Adem

 

[XL83NL]

Please dont double post your question in 2 subforums (Metal/metallurgy section).
I have no real good answer to your question but I suspect there's no real problem either, wrt corrosion.
We've used SWPND's with carbon outer rings in stainless systems, and stainless spiral windings in carbon piping sytems, etc... no real issue really.
But maybe some expert here can help you?

 

[Leonardobetta]

Already i've replied in the previous subforum.In this regards, i totally recommend in not doubling your post question in various Subforums. Besides, pls refer to the below answer for your inquiry:

bolting and gasket insulation kit is recommended. Pls refer to the below website:

http://www.corrosionservice.com/docs/Flange

Insulating Gasket-TYPE E:
Type E is a full-faced gasket with
the same outside diameter as the
flange and precision cut bolt holes.
This design facilitates proper
alignment of the gasket during
installation and foreign material is
prevented from shorting the flange
insulation. Type E gaskets are
available in plain face or Neoprene
face phenolic, as well as a variety
of high temperature materials.