MODEL "BQ" BACK PRESSURE RELIEF REGULATOR,GRAPHITE/NBR GASKETS 1/2" INLETS,1/2" OUTLET; SALES KIT A; BRONZE BODY,DUCTILE IRON SPRING CHAMBER; B5 TRIM: BRASS WITH TFE SEAT,PHOS.BRONZE DIAPHRAGM; SPECIAL RANGE SPRING; PER SPQ/MA DRAWING NUMBER 32966 SPECIAL 250-350 PSIG RANGE SPRING; FOR LIQUID CARBONIC CORP