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interior and exterior surfaces with a fusion bonded epoxy <br /> paint conforming to AWWA C-550. <br /> ' C. The gate shall be fully covered with a rubber cover over all <br /> exterior and interior ferrous surfaces. The rubber shall be <br /> securely bonded to the gate body, including the part which <br /> houses the stem nut. The gate and rubber coat shall conform <br /> to ASTM D429. <br /> ' d. Valve stems shall be cast bronze. The stuffing box shall use <br /> "O"-ring seal type with two rings located above the thrust <br /> ' collar. The rings shall be replaceable with the valve fully open <br /> and under pressure. <br /> ' e. Valves larger than 12" diameter shall be designed for <br /> horizontal installation with beveled gear boxes with reduction <br /> gears to reduce the number of turns required to operate <br /> valve. <br /> 3. Double Disc Type Gate Valves: <br /> ' a. Gate valves larger than 24" diameter size shall be of the <br /> ductile iron body, double disc parallel seat type meeting the <br /> ' requirements set forth in AWWA C-500. All valves shall be <br /> from one manufacturer and parts interchangeable. Valves <br /> ' shall have a working pressure of 150 psi. <br /> b. Gate valves shall have body, bonnet and gate manufactured <br /> ' of ductile iron conforming to ASTM A-536. The shell <br /> thickness of all components shall conform to the thicknesses <br /> in C-500. The valve body and bonnet shall be coated on both <br /> the interior and exterior surfaces. <br /> C. The gates shall be high strength cast iron, sturdily <br /> proportioned without pockets on the backs. All cam surfaces <br /> ' shall open to the bottom. Gate rings shall be rolled into a <br /> dovetail groove under pressure to make a single insertable <br /> finish. <br /> d. Valves shall use bottom wedging type design with a two part <br /> floating wedge contact. The wedge and hook shall be <br /> separate castings and not a single piece. <br /> ' e. Valve stems shall be cast bronze. The stuffing box shall use <br /> "O"-ring seal type with two rings located above the thrust <br /> ' Rev..10/22/01 PROJECT#13.01126 02640-Page 3 <br />