hi,
what is the size of pipe and wall thickness?
what is the size of Tee and what is the load acting on the TEE and Trunnion?
what is the temperature and pressure? its all matter.
if your load and size of tee is bigger, definitely you have to do seperate FEA analysis for finding what is the trunnion size to support tee,you have to check the tee and tunnion are able to withstand the loads etc.
finally you can find SIF in FEA and you can use same SIF values to the caesar analysis.
regards,
N.venkatachalam