Positive material identification (PMI) requirement for Super Duplex material
Positive material identification (PMI) requirement for Super Duplex material
(OP)
Hi
As per ball valve datasheet body material is carbon steel(A105) but the trim is super duplex stainless steel( UNS S32750). Please clarify whether positive material identification is required for super duplex material for valve internals parts.The the body material is carbon steel only(no requirement for PMI as per my understanding).
As per ball valve datasheet body material is carbon steel(A105) but the trim is super duplex stainless steel( UNS S32750). Please clarify whether positive material identification is required for super duplex material for valve internals parts.The the body material is carbon steel only(no requirement for PMI as per my understanding).





RE: Positive material identification (PMI) requirement for Super Duplex material
RE: Positive material identification (PMI) requirement for Super Duplex material
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.
RE: Positive material identification (PMI) requirement for Super Duplex material
As specified by Steve Jones, API-578 is the most common industry guideline for PMI.
Pradip Goswami,P.Eng.IWE
Welding & Metallurgical Specialist
Ontario,Canada.
ca.linkedin.com/pub/pradip-goswami/5/985/299
RE: Positive material identification (PMI) requirement for Super Duplex material
If you are taking about new items then you need a procedure, perhaps based on the API doc.
And in general PMI is only for general grade verification, not chemical analysis.
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P.E. Metallurgy, Plymouth Tube
RE: Positive material identification (PMI) requirement for Super Duplex material
Check the title and the scope of API RP 578 - they include the words "new," "vendors," "supply," and so on.
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.
RE: Positive material identification (PMI) requirement for Super Duplex material
RE: Positive material identification (PMI) requirement for Super Duplex material
For what it's worth, I've personally seen swaps from parallel manufacturing lines that slipped past manufacturer's QC and were shipped with incorrect MTRs. Most recent was a set of Inconel valves that had Monel bonnets. Drawings and MTRs all called out 825...
If it's absolutely critical that you have super duplex in there, I'd think you'd want to PMI.
Nathan Brink
RE: Positive material identification (PMI) requirement for Super Duplex material
If the alloy is really that critical let me ask two questions,
When was the last time that you did a physical audit of the supplier?
and how often have you had valve parts destructive tested to see if they actually meet the required specifications?
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P.E. Metallurgy, Plymouth Tube