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r <br /> 2 .2.6 . Gate Valves & Valve Boxes <br /> Methods of Construction <br /> i cutting and shall locate valves and fittings in the exact <br /> The Contractor shall do all necessary pipe g g <br /> positions indicated. He shall provide and use cutting tools of an approved type and in good order <br /> so as to ensure clean, square cuts to exact measurements. <br /> Examination of Material <br /> Prior to installation, valves shall be inspected for direction of opening, number of turns to open, <br /> freedom of operations, tightness of pressure containing bolting and test plugs, cleanliness of <br /> valve ports and especially seating surface handling damage and cracks . Defective valves shall be <br /> corrected or held for inspection by the Engineer. Valves shall be closed before being installed. <br /> Placement <br /> Mains shall be drained through drainage branches or blowoffs. Drainage branches, blowoffs, air <br /> vents and appurtenances shall be provided with valves and shall be located and installed as <br /> shown on the plans. Drainage branches or blowoffs shall not be directly connected to any storm <br /> or sanitary sewer submerged in any stream, or be installed in any other manner that will permit <br /> back siphonage into the distribution system. <br /> A valve box shall be provided for every valve that has no gearing or operating mechanism or in <br /> which the gearing of operating mechanism is fully protected with a gear case. The valve box <br /> shall not transmit shock or stress to the valve and shall be centered over the operating nut of the <br /> ' valve, with the box cover flush with the surface of the finished area or such other level as may be <br /> directed by the Owner. <br /> All valves shall be set accurately true to and square with pipe lines and installed on a 2500 psi <br /> concrete foundation so that the pipe will not be required to support the weight of the valve . <br /> Valves shall be installed in the closed position. Valve stems shall be accurately plumb. Valve <br /> boxes shall be set plumb accurately centered with respect to the valve stem, well supported by <br /> solidly tamped earth and with their tops flush with the finished surface grade of the roadway or <br /> surface of the ground where set. Pipe lines shall be thrust blocked at all bends greater than 10 <br /> degrees and at all tees, plugs, valves and fire hydrants so as to prevent movement of the lines <br /> under pressure. Typical thrust blocking shall be as shown on the detail sheet of the plans or as <br /> described by the Engineer. <br /> 19 <br />