Specifications include, but are not limited to: Description Butterfly valves, as described herein, shall be rubber seated, iron bodied valves suitable for direct burial type installation in a water distribution system and shall be capable of being installed with normal pipeline installation methods. B. NSF 61 Approval All valves provided shall be in compliance with NSF 61 Drinking Water System Components - Health Effects. C. Standards Unless otherwise stated, the valves shall conform to the latest revisions of the following American Water Works Standards: 1. AWWA C504 Standard for Rubber-Seated Butterfly Valves 2. AWWA C111 Standard for Rubber-Gasket Joints for Ductile-Iron Pressure Pipe and Fittings 3. AWWA C550 Standard for Protective Interior Coatings for Valves and Hydrants 4. AWWA C110 Standard for Ductile-Iron and Gray-Iron Fittings