NEMA SM23 and Nozzle loads & Moments 2

[SENGUTTUVAN]

A basic clarification is sought. Normally for the pumps there is API standard which clearly specifies the Allowable Nozzle forces and moments in various directions. But for the Turbines eventhough there are API standards, why NEMA SM23 is being referred? Why this is not specified in API?

 

[JohnBreen]

SENGUTTUVAN

The Standard specified by the turbine manufacturer or by the turbine owner may be API or it may be NEMA SM-23 (or SM-24). It is up to the manufacturer or the owner to decide which Standard is to be applied. You must apply the specified Standard in your analysis. If your pipe loadings exceed the manufacturer's limits but are "close to" the maximum allowable loadings they should be submitted to the turbine manufacture as the manufacturer MAY accept them.

SM-23 is a bit conservative and it is also a little vague on how the calculations are to be done. If you are to use SM-23 study it closely and also study the sample "problems" that are provided. If you are a "first-time user" of SM-23 you WILL have many questions to ask. You will get NO help with interpretation from NEMA, so you will have to ask your questions on internet discussion forums and hope for the best answers.

Regards, John