(A) Any backflow prevention device required by this subchapter shall be of a model or construction approved by the city’s Water Division.
(1) An air gap separation, to be approved, shall be at least double the diameter of the supply pipe measured vertically above the flood level rim of the vessel, but in no case less than 1 inch.
(2) A double checkvalve assembly or a reduced pressure principle backflow prevention device shall be approved by the city’s Water Division and shall appear on the current list of approved backflow prevention devices established by the Water Division.
(B) Existing testable backflow prevention devices approved by the water purveyor at the time of installation and properly maintained shall, except for inspection and maintenance requirements, be excluded from the requirements of this subchapter so long as the city’s Water Division is assured that they will satisfactorily protect the water system. Whenever the existing device is moved from its present location, or requires more than minimum maintenance, or when the Water Division finds that the maintenance constitutes a hazard to health, the unit shall be replaced by a backflow prevention device meeting the requirements of this subchapter.
(Prior Code, § 52-147) (Ord. 2939, § 1, 12-14-1993)