ASME B16.23 pdf download Cast Copper Alloy Solder Joint Drainage Fittings: DWV 7 MARKING (a) Each fittingshall be marked permanentlyand legi- bly with the manufacturer’s name or trademark and with “DWV” (to indicate Drain Waste Vent). (b) Vent fittings shall be permanently marked “VENT ONLY” (See Tables 43, 44, I-43, and I-44) and show the manufacturer’s name or trademark in...