We are doing a Stress Analysis for a high pressure CO2 line (Urea Plant) with the following parameters,

Design Pressure 228 kg/cm2, Maximum Line Temperature of 70 deg Celsius, 6” pipe Sch.160, flange rating 2500#, Piping material SS.

The scope of work involves slight modification in the pipe routing with the addition of Check valve (6”-2500#) as marked in the attached drawing. The Co2 line is supported by two spring supports near to the Stripper Vessel (attached in this forum). We required to check whether the existing spring support shall be suitable as per new pipe routing.

Since the Stripper Vessel is provided with an expansion joint (Total axial displacement 15mm), also it is the first time for me to deal with such a vessel, I request the forum members to give me a suggestion for modeling a vessel. Also the Vessel nozzle (N3) shall be checked with WRC 297, I modeled the vessel nozzle (without considering expansion joint – since I am not sure to model it) as per “Coade Pipe Stress Analysis Seminar Notes, Sec. 3.4.3.2 – Modeling Nozzles for flexibility calculation, figure 3-90 – More complex model.

The Caesar Input sheet is also attached with the forum.

I request the members to provide me a method of modeling vessel with expansion joint, also comments (if any) on the modeling of vessel nozzle.

Also, when the vessel nozzle is modeled in a simple method, for the [b]sustained and hydrostatic case the vessel nozzle load seems to be much higher, while locating the spring support at the same location. Can someone find me a solution to solve this.[/b]