7.0 Equipment nozzle loading:


As explained earlier pipe stresses are calculated for various type of loading such as pressure, weight, thermal etc. and it is reviewed whether the stresses are within allowable limits. However in lot of cases pipe stress analysis becomes critical and rather complicated because it is not only stress of piping but the nozzle loading of the various equipment which has to be kept within allowable limits.


For rotating equipment’s like steam turbines, compressors centrifugal pumps,

various codes like NEMA SM-23, API-617, API-610 etc. give guidelines regarding the allowable nozzle loading. For the analysis of these piping connected with various rotating equipment, vendor also provide information regarding nozzle movements and allowable loads. It is the responsibility of the equipment engineer to ensure that the allowable loads as agreed by vendors are always equal to or greater the values as per the respective applicable code. Various computer packages now have equipment nozzle check features. However the pipe stress engineers are advised to study the specific applicable codes also as this will give them a further insight for solving specific problems related to equipment nozzle loading.