The stiffness of the device nozzles is as important as their resistance to concentrated loads. They decide whether the analyzed nozzle will pass the test in the pipeline strength calculation program. Unfortunately, there is little awareness of this fact. Usually, the nozzle stiffnesses are "pulled" from the settings of the pipeline calculation programs. Their values are random and certainly do not correspond to the actual values.
The stiffness should be determined quite accurately and reliably, preferably in FEM programs or possibly estimate using known formulas, let's say from the Kellogg company book. The results of the FEM analysis of the apparatus nozzle are shown below.
