All,
I heard that NEMA SM 23 is withdrawn.
What is the reson and what is path forawrd?
Can anyone answer please.

Hi,

indeed the NEMA website says it has been withdrawn, but they don't seem to give any reasons.
NEMA SM 23-1991 (R1997, R2002) Status: Rescinded

And (I didn't know) it has been rescinded for a long time:
Thread form Eng-Tips.com (2014) This thread provides the hint to check API Std 611. (General Purpose Steam Turbines for Petroleum, Chemical, and Gas Industry Services 5th 2008; Reaff. 2014)

We use NEMA SM-23 for its allowable forces and moment method, within the API Std 617 Axial and Centrifugal Compressors and Expander-Compressors.

best regards,

API-611 refers you back to NEMA for nozzle load limits. That isn't much help at all ...

Sorry that I don't answer your question, but I was wondering it is common to use NEMA SM23 in process piping area.

I've been in power piping area few years, and only at 1 project, steam turbine vendor insist of using NEMA-SM23(but former project with same vendor had provided their own standard, I asked why and they said that turbine type is different).

I guess they do provide thier own standards these days...

Any opinions would be helpful.