selection of CRA materials for piping

[majicmajic]

Dear All

Good day.


I wanted some expertise on the basis of selection of duplex and CRA materials.

I have seen duplex, super duplex, 6Mo ( UNS 31254), inconel ( UNS 6625), incoly ( UNS 8825), Clading by 6625 / 8825 in piping material class for process hydrocarbon / well head fluids.

How we can select the suitable one from the above if we have a system. Is this based on MSR report?

Pls share your experience

 

[Duwe6]

Choice is based on the severity of the service conditions, and 'other folks' experience with those conditions and fluids. Hopefully, your fluid and conditions [temp. & pressure, flow velocity] are documented in the reference literature -- then use the recommended stuff.

With undocumented conditions and fluid, start doing corrosion rate studies to include highly stressed coupons that get tested for Stress Corr. Cracking. Good Luck - it takes a couple of years and a bunch of lab time. And you may have the same result we had; no metals [other than tantalum and possibly gold] would work. We went to glass-lined and still 'use up' a reactor in less than 1-year.

 

[SJones]

Consult the following:

ISO 21457
NACE SP0407

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.

 

[weldstan]

Metallurgy selection is based on fluid(s) temperature, pressure, % water, % H2S, % CO2, % Chlorides, etc. both now and expected in the furure. It's also determined by overall economics over the life of the well and whether or not to use corrosion inhibitors. I suggest you employ the talents of a corrosion metallurgist experienced in the field.