Dear Moderator,

I have a vessel designed with ASME Sec VIII Division 1 Addenda 2008. I would like to know how the Minimum temperature at required thickness is calculated (appearing in nozzle calculations). Following is taken from nozzle calculation output. I would like to know how the value of -103C is arrived. Please help.

Nozzle, tg = 11.070 , tr = 0.581 , c = 5.000 mm , E* = 1.00
Stress Ratio = tr * (E*) / (tg - c) = 0.096

Minimum Temp. w/o impact per UCS-66 -26 C
Minimum Temp. at required thickness -103 C
Minimum Temp. w/o impact per UG-20(f) -29 C

Thanks and regards,
Sarog

As, coincident ratio is less then 0.35(ref. fig. UCS-66.1) para UCS-66(b)(3) to be followed. i m just rewriting the same here :
When the minimum design metal temperature is colder than −55°F (−48°C) and no colder than −155°F (−105°C), and the coincident ratio defined in Fig. UCS-66.1 is less than or equal to 0.35, impact testing is not required.

As per above statement Minimum temperature will be 105°C. But PV Elite has calculated 103°C and it's conservative. i think it's calculating correctly.