Pressure rating and Schedule number apply to pipe.
If the joint yokes were machined from pipe, I'd worry about using them, since there may be welded seams where you don't want them, and mechanical properties are not guaranteed to the same standards.
More likely, somebody's database is screwed up, and you can't trust getting the correct specs on any item from that supplier.
Mike Halloran
Pembroke Pines, FL, USA