HH1150 double age as per NACE MR-01-75 1

[arunb]

Hi,
I have requirement to use 17-4PH stainless steel(Condition H1150) for valve stem.
I have an offer for HH1150 double age as per NACE MR-01-75 from a supplier. Can I use this instead?
I can't find the specification properties for HH1150, these are not listed in ASTM standards- do I assume them to be the same as H1150.
Appreciate any information on this.
Regards
arunb

 

[unclesyd]

We use 17/4 PH HH1150 interchangeably with H1150 all the time. We use the specification properties for the H1150 heat treatment for both conditions. The numbers that I have for actual tests of both the H1150 and the HH1150 heat treatments are significantly higher than the specification values.

 

[Scotsinst]

Please note FYI that 17-4PH is no longer acceptable for NACE MR0175-2003. The "new" NACE MR0175-2003 is much more limited than the previous edition.

 

[rorschach]

Scotsinst, I must take exception to your statement concerning 17-4PH and NACE MR01-75-2003, according to table A.27 of the standard, as long as the partial pressure is below 0.5 psia, then 17-4 is allowed for christmas tree and valve components. Under other tables for other applications 17-4 HH1150 (and not H1150 BTW, they are not interchangeable per NACE as unclesyd implied. H1150 is not allowed per any of the tables I checked.) is generally allowed without exception depending on the application.

 

[redpicker]

I believe unclesyd was saying that HH1150 could be substituted for H1150 (orivuded the mechanicals for the H1150 were satisfied). I didn't think he was saying that H1150 was suitable when HH1150 was specified.

(if that wasn't what he meant, it should have been)

rp

 

[unclesyd]

redpicker,
You are correct.
My intent was solely to answer arunb'squestion concerning the substitution of an HH1150 stem for a H1150 stem for his valve and no more. There was no environmental considerations, only physicals of which I could have done a better job conveying to eliminate any confusion.