API Plan 52 vs API Plan 72 for temperature over 200 deg C

[Aisyahaulianisa]

Dear all,

i would like to ask your opinion
Which mechanical seal plan is better for operation condition below?

Pumping liquid : etilene benzene
Temperature : 234 deg C
SG : 0.664
vapor pressure : 3.37 kg/cm2

API plan 23 / 52 or
API plan 23 / 72 + 75

FYI : Our client refuse to use API plan 23 / 72+75 due to high differential temperature between Inner seal (pumping liquid) and Outer seal (Gas Nitrogen), there will be N2 gas expantion which is bad for mechanical seal.

Also, please advise the temperature of gas nitrogen for API Plan 72? is it ambient temperature or low temperature?

Thanks Regards