B31.3 Welding strength checking weldolet to weld in thermowell

[abehong]

We have a case with Shell Improve group where a 2” 40 sch weldolet, already welded to the 24” main pipe, has to be welded to a Sch 160 welding in thermowell . So there is misalignment on the butt welding between welding in thermowell and weldolet . My question is how to dertermin if the weld area has enough strength to wisthstand tha load due to internal pressure and also if there is any requirement on minimum welding size per B31.3. Thank for your reply.