It would seem that in B.C., design registration and Canadian Registration Numbers (CRN) for pressure piping components (fittings) used in oil and gas activities are no longer required? Is this correct?

Yes this is correct, the legislation refers directly to ASME B31.3 as an acceptable design code (not CSA B51), therefore design registration is not required for process pressure piping and fittings. In cases where CSA B51 is the design standard, design registration is required. A proponent may still choose to register for CRNs in any circumstance and can do this through Technical Safety BC.