MODEL "DA4" PRESSURE LOADED REDUCING REGULATOR (SERIES IV)-PLPRV BODY SIZE 1",STANDARD DIAPHRAGM CONSTRUCTION; BRONZE BODY & LOADING CHAMBER; MONEL M TRIM, PA SEAT, FK DIAPHRAGM FK STATIC SEAL, SST/TFE U-CUP DYNAMIC SEAL; NPT END CONNECTION;OPT-55: CLEANED FOR OXYGEN SERVICE PER SPEC #S-1134