2:1 ELLI. HEAD
A NOZZLE Fitting in Center Of the head
to met requirement of UG45b.1

tr=P*D*K / 2*S*E-0.2P=a (K=1) according to Appendix 1-4(c)
=2.4
or

tr=P*D*K1 / 2*S*E-0.2P (K1=0.9) per UG-37(a) (3)
=2.3

I am think to met UG45b.1，"tr" must calc. Per the sencond formula, the result is 2.3(fox example)
but why pvelite calc tr per the first formula,the result is 2.4,
why?????

UG45.b.1
"for vessels under internal pressure only,
the thickness (plus corrosion allowance) required for pressure
(assuming Ep1.0) for the shell or head at the locationwhere the nozzle neck or other connection attaches to the
vessel"

mention the word "at the location"

Petty,



Please note that since the nozzle is located on the head, tr shall be equal to the thickness of the head, calculated as per UG-32 or Appendix 1-4(c).

tr as per UG-37(a) (3) shall be used in case of reinforcement calculation.

Pvelite is doing the corrrect calcualation.

Regards,
SKY