327 IAC 8-3.2-14 Placement of isolation valves and air relief valves

Sec. 14. (a) Isolation valves shall be provided on water mains in accordance with the following: (1) Isolation valves shall be located at points necessary so that the maximum distance along the water main not served by an isolation valve shall be less than six hundred (600) linear feet. (2) Where water suppliers serve widely scattered customers and where future development is not expected, the isolation valve spacing shall not exceed two thousand five hundred (2,500) linear feet. (b) Air relief valves or other air relief devices shall be installed at any intermediate apex points in the water main where air may accumulate in the water main. All air relief valves must be equipped with an exhaust pipe extending to a downward facing elbow with a corrosion-resistant, twenty-four (24) mesh screened opening at an elevation of eighteen (18) inches above ground level. Automatic or manually operated air relief valves shall be selected in accordance with the following: (1) Automatic air relief valves shall not be used in areas within the one hundred (100) year flood plain, in a pit, chamber or manhole where flooding may occur unless the automatic air relief valve is equipped with a downward facing exhaust pipe with a corrosion resistant, twenty-four (24) mesh screened opening at an elevation of eighteen (18) inches above the ground surface and above the one hundred (100) year flood elevation. (2) Manually operated air relief valves shall be used in areas within the one hundred (100) year flood plain, in a pit, chamber, or manhole where flooding may occur.