Specifications include, but are not limited to: 2.01 BUTTERFLY VALVES FLANGED A. Butterfly valves 24-72” (600mm and larger) shall meet or exceed the latest revision of AWWA Standard C504 and shall meet or exceed the requirements of this specification. All valves shall comply with the requirements of the AWWA class specified or if the AWWA class is not specified, the valve shall meet the requirements of AWWA C504 class 150B. B. Valve bodies shall be of cast iron per ASTM A126 Class B. Flanged end valves shall be of the short body design with 125lb. flanged ends faced and drilled per ANSI B16.1 standard for cast iron flanges. Mechanical joint ends shall meet the requirements of AWWA C111/ANSI A21.11. C. Discs shall be offset to provide an uninterrupted 360-degree seating edge and shall be cast iron per ASTM A48, Class 40C or ductile iron per ASTOM A536 (65-45-12). The disc seating edge shall be solid 316 stainless steel. The disc shall be securely attached to the valve shaft using 304 stainless steel. The disc shall be securely attached to the valve shaft using 304 stainless steel taper pins. Discs structures containing hollow cavities are not acceptable. D. Valve shaft shall be of type 304 stainless steel. Valve shaft seals shall be self- compensating V-type packing with a minimum of four sealing rings. One-piece molded shaft seals and o-ring shaft seals are not acceptable. E. The seat shall be of Buna-N for water, or as required for other services, and shall be retained within a dovetail groove in the valve body and locked in place by an epoxy compound edge. Compression between the seat and disc edge shall be adjustable from both the upstream and downstream side of the valve disc and the seat shall be field replaceable without disassembly of the disc and shaft. Seats with unidirectional adjustment, seats retained in the valve body by the use of fasteners and/or retaining rings, and seats retained on the valve disc are not acceptable. F. Valve shaft bearing shall be Teflon lined with a non-metallic fiberglass composite backing and shall be permanently lubricated. G. Unless otherwise specified, exterior and interior metallic surfaces of each valve shall be shop painted per the latest reversion of AWWA C504.
