Question:

Are UG-22 loads considered in COMPRESS? Where in COMPRESS can I find this indication?

Answer:

The Settings Summary report defines the loads per UG-22 that are considered by COMPRESS. These include:

• UG-22(a) internal/external pressure
• UG-22(b) weight of vessel and normal contents
• UG-22(c) static reactions from attached equipment (these are entered as vertical or lateral loads)
• UG-22(d)(2) vessel supports
• UG-22(f) wind/seismic

The Settings Summary does not address UG-22(d)(1) internals. However, I would consider these to be accounted for if the vertical or lateral loads are added to account for these. Also, the weight of such internals is considered if they are included in the COMPRESS model.

Note that COMPRESS will not consider loads on nozzles and clip/lug attachments as analyzed by Welding Research Council bulletin WRC-107 as meeting definition or requirement of UG-22(c). Such loads are analyzed only for the effect of local stresses in the shell. Their effect on the entire circular cross-section of the vessel and on vessel supports is not considered in the WRC-107 analysis.

There are no current plans to add consideration of:

• UG-22(e) cyclic (fatigue) loading
• UG-22(g) impact reactions
• UG-22(h) temperature gradients
• UG-22(i) deflagration, etc.

These loads are outside the scope of COMPRESS. I suggest using a program like FEPipe or Nozzle Pro (both available through Codeware) if these loads must be considered.