For the purpose of this chapter, the following definitions shall apply unless the context clearly indicates or requires a different meaning.
AIR-GAP SEPARATION. A physical break between a supply pipe and receiving vessel. The air- gap shall be at least double the diameter of the supply pipe, measured vertically above the top rim of the vessel in no case less than one inch, with no ties or connection between the device and meter.
APPROVED. Those devices as approved by the Foundation of Cross-Connection Control.
APPROVED CHECK VALVE. A check valve that seats readily and completely and has been previously approved for use in this service by the city. It must be carefully machined to have free moving parts and assured water tightness. The face of the closure element and valve seat must be bronze, composition, or other noncorrodible material which will seat tightly under all prevailing conditions of field use. Pins and bushings shall be of bronze or other noncorrodible, nonsticking material, machined for easy, dependable operation. The closure element (i.e., clapper) shall be internally weighted or otherwise internally equipped to promote rapid and positive closure in all sizes where this feature is obtainable.
APPROVED DOUBLE CHECK VALVE ASSEMBLY. An assembly which has previously been approved for use in this service by the city and consists of at least two independently acting approved check valves including tightly closing shutoff valves on each side of the check valve assembly and suitable leak detector drains plus connections available for testing the watertightness of each check valve, with no ties or connections between device and meter.
APPROVED REDUCED PRESSURE PRINCIPLE BACKFLOW PREVENTION DEVICE. A device which has previously been approved for use in this service by the city and consists of incorporating two or more check valves and an automatically operating differential relief valve located between the two check, two shutoff valves, and equipped with necessary appurtenances for testing, with no ties or connections between the device and meter.
(1) The device shall operate to maintain the pressure in the zone between the two check valves less than the pressure on the public water supply side of the device.
(2) At cessation of normal flow, the pressure between check valves shall be less than the supply pressure.
(3) In case of leakage of either check valve the differential relief valve shall operate to maintain this reduced pressure by discharging to the atmosphere.
(4) When the inlet pressure is two pounds per square inch or less, the relief valve shall open to the atmosphere, thereby providing an air-gap in the device.
(5) To be approved, these devices must be readily accessible for maintenance and testing and installed in a location where no part of the valve will be submerged.
APPROVED WATER SUPPLY. Any water supply approved by or under the public health supervision of a public health agency of the state, or its political subdivisions. In determining what constitutes an approved water supply, the State Department of Public Health reserves final judgment as to its safety and potability.
AUXILIARY SUPPLY. Any water supply on or available to the premises other than the public water supply.
CROSS-CONNECTIONS. Any actual or potential unprotected connection between any part of a water system used or intended to supply water for drinking purposes and any source or system containing water or substance that is not or cannot be approved as safe, wholesome, and potable for human consumption.
('61 Code, § 24.91) (Ord. 604, passed - - )