INCONEL 625 weld overlay

[VALVULA]

good day...

we are specifying 1500# carbon steel ball valves for a NACE project (10000 ppm H2S)

our costumer is requesting Ring joint cavity of RTJ Flanged end valve shall be supplied with Inconel 625 weld overlay

ball valves are normally A105, A216 WCC or A694 F60

could any one advice about this practice???

what is it useful for???

how we can ovoid this???

any suggestion will be highly appreciated.

BRs

 

[EdStainless]

In some service the real corrosion concern is crevice corrosion, and it is the most severe in the tightest crevices.
Therefore use CRA weld overlay on flange sealing faces is common practice.

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P.E. Metallurgy, Plymouth Tube

 

[MJCronin]

Contact the largest manufacturer/vendor of this type of valve. Talk with the technical rep for this company.

Ask about their prior experience with a Inconel 625 weld overlay on the ring joint cavity of a carbon steel valve.

(Seems very strange to me, but I am one voice in the wilderness ..)

If no one has ever done this before, and your client is requesting a unique or unusual configuration, he should be notified.

I wonder if you may be miss-reading a specification or if there has been some type of typo ....

Please respect us and share with us what you learn and the final resolution to this problem

MJCronin
Sr. Process Engineer

 

[SJones]

It's a pretty common practice on Xmas trees and subsea items to avoid corrosion of the sealing surface.

EEMUA 194
In many cases, however, CRA gasket materials are required, particularly where
internal corrosion from the transported fluids is expected. Typically, Type 316 SS
or Alloy 825 is specified, with a hardness limit of about 180–200 HB. Where
these materials are specified, corrosion resistant inlay of the ring groove is also
often required, normally Alloy 625 weld overlay. (Note: ISO 13628-1 requires
that all subsea flange connections be made with CRA gaskets and inlaid ring
grooves).

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/pub/8/83b/b04

All answers are personal opinions only and are in no way connected with any employer.