Plumbers and Pipefitters Local Union No. 520 v. National Labor Relations Board, Ue & C-Catalytic, Inc., Intervenor

Opinion for the Court filed by Circuit Judge EDWARDS.

HARRY T. EDWARDS, Circuit Judge:

The simple question in this case is whether the National Labor Relations Board (“NLRB” or “Board”) may give deference to a pre-arbitration settlement reached by an employer and a union disposing of an employee’s contract grievance with respect to a matter covered by the parties’ collective bargaining agreement. The simple answer is yes.

In this case, the applicable collective bargaining agreement between UE & C-Catalytic, Inc. (“Catalytic”) and fourteen International building trades unions — the General…