Hello

I have a quick question regarding the exp_jt design per app 5(thick/flanged & flued type)with ref to the new PV-Elite build.

Previously(for PV ELite 2004),i used to calculate the exp_jt spring rates per TEMA and than used those as an input for the exp_jt design per ASME.In this new build,if an exp_jt is designed per ASME UHX,it displays the corroded/un-corroded spring rates in the output report and we no longer have to switch back and forth b/w TEMA and ASME for calculating the spring rates.Now,i have two questions that needs clearification:

1)Are the spring rates & max stresses in the annular rings are calculated based on ASME or TEMA when you run your design of H.E per ASME?

2)Once you get the spring rates(both corroded/uncorroded)per ASME;do you still need to enter those spring rates as an input in the EXPANSION JOINT DATA dialogue box?(thats what i used to do previously)

COADE must post some detailed articles for H.E in order to elaborate such confusions

Thanks
Naveed

Hello Naveed,

In the 2005 version we have integrated the thick expansion joint calculations within the ASME tubesheet module (it was already integrated in the TEMA tubesheet module).

In the ASME tubesheet module, these are the steps followed for a fixed tubesheet with a thick expansion joint:

• Use the TEMA formulae to compute the thick expansion joint spring rate.
• Then automatically use that computed spring rate to check the tubesheet/tubes/shell/channel per ASME UHX rules.
• Then use the TEMA formula to compute the prime pressures (ps', pt' and pd) for the tubesheet. This represents the equivalent pressures acting on the expansion joint. Part UHX of ASME code at this time (A-2004) does not provide these pressures.
• Use these prime pressures to compute the expansion joint stresses per TEMA.
• Compare the expansion joint stresses with the ASME code allowables per appendix 5.

So, you do not have to manually transfer the data from the expansion joint to tubesheet modules any more.

In the tubesheet module, once you have entered the expansion joint geometry then the program can compute its spring rate and use it. So, you do not need to re-enter the spring rate back in the input.

I hope it helps.