Hi,
Excuse me the Ingles. I’m making the stress analysis for a pumps systems checking the stresses with the design temperature and the nozzles loads with the operation temperature, now this consideration is normally used for this cases, but I don’t found in which code (ASME or API), I can support this consideration.

Regards,
Jose.

ASME Codes and API Standards do not say clearly about pump nozzle loads for the specific temperature case but we have to meet the code stress in accordance with the piping codes for any temperature case but there has been had argument for the nozzle load evaluation.

Some clients/ or engineering companies allow to use 50% or more allowables in their project spec. or detail work instruction for following cases;
1) the design(or upset, steam-out) case temp.
2) stand-by(idling) pump
3) transient friction case during start-up/shut-down
If there is no requirement, it always give a rise to argument.

You can get some ideas from the WRC449, "Guidelines for the Design and Installation of Pump Piping System"