ASME B31.3 - Section 304.3.3

I am a little confused on the interpretation of the half width of the reinforcement zone according to ASME B31.3.

The way I interpret it is that d2 can have one of two values. d2 can either be equal to d1 or equal to the equation listed in section 304.3.3. d2 will be the larger of these two values but will not exceed the OD of the header pipe.

For example, I ran a calculation on a 14" x 14" lateral (45 degree connection). My d1 value was roughly 19" and the d2 value (through the equation) was roughly 10". d1 is the larger value but d1 is greater than 14" so I chose 10.5" as my d2.

I have recently run across a spreadsheet that compared d1 and d2 and then compared the larger value to the header OD. When I tried my lateral on this spreadsheet, it gave me a d2 value of 14". To me, this means that the author of this spreadsheet interpreted the code to mean that you find the larger value of d1 and d2 and if the larger of the two is greater than the header OD then the header OD is used for d2.

I believe one of the two of us is right but I don't know which one. Could someone with more experience with the code help me out?