heat transfer

hello to all,

Would we burn any seals by WPHT close to the monoblock as in the dwg attached?

data:

pipe: 24" Ø x 0.938" API 5LX60
code: Asme 31.8
service: Nitrogen
monoblock: 24"Ø 1500#
distance center to center (monoblock to wpht): 6.23'
temperature max of wpht: 1000°F
air temperature: 77°f

ACCORD THE MONOBLOCK VENDOR THE PIPELINE WITH NORMAL WELDING PROCEDURES USING A MAXIMUM PREHEAT OF 250F.

can anybody help me with some calculates or charts?

thanks for your time

You better study the thermal properties of its seals, what is its maximum resistance to heat before burn occurs.

Calculation would be the same as to heat transfer. YOu have atmospheric temperature and inside temperature of pipe (dT). Get the also the thermal coefficients of the pipe, are and thickness. In that way you will be able to get the heat transfer.