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2020.01 <br />The work to be <br />gate valves. <br />2020.02 <br />Unless otherwise <br />distribution system 4 inches through <br />strictly with the latest specification <br />comply with the following supplem <br />(a) Bodv <br />Gate valves shall be <br />be hydrostatically tested at 300 psi ani <br />rejection. For ease of repair the body <br />bolts and nuts. Each valve shall have <br />cast in the body. <br />under this specification shall consist of furnishing and installing <br />ved in writing, all Gate Valves for d'uect buried service in the City's <br />inches in diameter shall be Resilient Seated Gate Valves that conform <br />509 of the American Water Works Association Standards and must <br />details, changes or addition. <br />n body designed for a working pressure of 200 psi. All valves shall <br />shell tested at 400 psi. Any leakage during testing shall be cause for <br />bonnet and stufflng box shall be flanged together with ASTM A-307 <br />the maker's initials, pressure rating, and yeaz in which manufactured <br />(b) Stems <br />Stems shall be machut d from manganese bronze rod, or manganese bronze castings, with an <br />integral trust collar machined to size. The steams shall be non-rising and equipped for nut operation, which <br />shall be opened by tuming to the left counter clockwise). <br />(c) Stem Seals <br />The seals shall consistl of two "O" rings above and one "O" ring below the thrust collaz. An <br />anti-friction washer shall be located a~bove the thrust collaz for operating torque. <br />N <br />(d) Stem ut <br />The stem nut shall be STM B-62 Bronze and shall be in[egrally cast with the valve disk in <br />a manner that will provide rigidity a Id positive travel stop, which shall be by metal to metal contact. <br />(e) Resilient Disc <br />Each resilient seat ga e valve shall conform to one of the following requirements: <br />(1) Resilient Seat Rings: The seat rings shall be attached to disc by 304 stainless steel <br />screws for easy replacement. The ri gs shall be molded natural rubber, internally reinforced with steel. The <br />rings shall seat against a machined, epoxy coated surface in the valve body. <br />(2) Encapsulated, Disc: The disc for all valve sizes shall completely encapsulated in <br />Urethane or Stryrene Butadiene rublber as per ASTM P-429, including stem bore, be field replaceable and <br />provide a dual seat on the mating body seat. <br />Item 2020-1 <br />