Tables UHX-13.1 & UHX-13.2 for 'F' & 'Z' Variables

[RedTruck]

I am making a UHX-13 tubesheet calculation for a configuration b fixed tubesheet heat exchanger. I have entered the math given in UHX-13 into MathCad, and I am not able to match the sample inputs given in UHX-20.2.1 to the given outputs. My results fall apart beginning at the output for the Fm variable. I believe my problem is that the tables give that x varies from 0 to Xa, but I do not know how to use that to find variables Qm, Qv, Fm in table UHX-13.1, and variables Zd, Zw, Ft, and Ft min & max in table UHX-13.2 that are functions of 'x'. Can anyone tell me how I can find the value of 'x' that I should put into these equations?

My results fall further in the UHX-20.2.1 results for step 9. There are results given for Fq, but I cannot find equations for Fq in step 9 of UHX-13.5.9. That variable does appear in the TEMA calculation.

This is a one time calculation for me. Most of our heat exchangers have rectangular tubesheets for which UHX does not apply. This one job is for a reverse engineered replacement shell and tube heat exchanger. We plan to provide tubesheets of the same thickness as the original, but our customer requires that we demonstrate by both TEMA and UHX that the original tubesheet thickness is valid for current calculations. Also, I want to know how to do the calculation.

I think my problem is a lack of knowledge in how to do this math. Thank you for your help.

 

[RedTruck]

I am able to update my question above. I found the Fq variable in the 2007 Code. It does not appear in the 2008 addenda, but the sample in UHX-20.2.1 is not updated. I added the formula for Fq to my Mathcad calculation, so I have that answer.

It appears my sticking point is what number to assign to the 'x' variable for the calculations in tables UHX-13.1 and UHX-13.2.

Can anyone help me with this?