ASME Fixed Tubesheet Design Conditions in PV Elite

[FPPE]

Hello,
I would like to understand how can be inputed the following load cases in PV Elite for a fixed tubesheet:




PV Elite has two main windows for these data:

(1) General windows "Load Cases":



(2) Minimum Pressures & Report Options for this Load Case:



I assumed that, according to the first table in the post, in the "Load Cases" screen, it is necessary to set 5 as the "Number of cases to process" and first fill in the data in the "Load Cases" screen. For this reason, I would need some help: for example, considering only the "Shell Start-up" case, where we need to take into account the inlet temperature on the shell side for tubes and shell (20 °C), while for the pressures, we need to enter the design pressure on the shell side (14 barg) and FV on the tube side. Is it correct to fill in the first screen as shown below?
The question is whether Full Vacuum pressures need to be specified with the "-" sign in the "Load Cases" screen.
Additionally, in the "Minimum Pressures & Report ..." screen, is it necessary to specify the minimum design pressures again (respectively, for the Shell Start-up case, 14 barg on the shell side and -1.034 barg on the tube side)?



and for the second pop-up window I selected all the items:



Could you please help?
Thanks in advance

 

[CuMo]

"Shell-side / Channel-side Vacuum Pressures
Enter positive values. For example, for full atmospheric vacuum condition enter a value of 15.0 psig. If no value is entered, then 0 psi is used."

I would be looking at the Output closely because noone knows what PV Elite sometime does behind the scenes.

I would first start with entering the worst Max Differential Pressure + Max delta T between shell and tubes combo that can ever exist, and see what this does to the exchanger.

Also you might want to keep your design temps for all metal at the highest possible. This would keep your metal design stresses low as possible for all cases
/Conservative/.

Then you can vary the Mean metal temps of shell and tubes to work out the maximum possible differential expansion in the exchanger which will generate the maximum axial loads that can ever exist. Well, in a normal operating/design scenario at least...

 

[Trestala]

considering only the "Shell Start-up" case, where we need to take into account the inlet temperature on the shell side for tubes and shell (20 °C), while for the pressures, we need to enter the design pressure on the shell side (14 barg) and FV on the tube side. Is it correct to fill in the first screen as shown below?

You keep the Design Temperature values as the design temperature, not the metal temperatures. There is a separate input for metal temperature below the design temperatures.

The question is whether Full Vacuum pressures need to be specified with the "-" sign in the "Load Cases" screen.

You specify the vacuum condition on the report options. It is gauge pressure, so you specify negative value (e.g. -1.03bar).
Try changing the units to US Customary and it specifies gauge (e.g. psig).



I noticed also you used the same Case 2 for different values.
You can flip through the "Active Load Case" to define 5 difference cases using the up/down arrows and assign different conditions for each.