As used in this article, the following terms shall have the
meanings indicated:
AIR-GAP SEPARATION
A physical break between a supply pipe and a 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.
APPROVED CHECK VALVE
A check valve that seats readily and completely. It must
be carefully machined to have free-moving parts and assured watertightness.
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, e.g., 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 of at least two independently acting 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. This
device must be approved as a complete assembly.
APPROVED REDUCED PRESSURE PRINCIPLE BACKFLOW PREVENTION DEVICE
A.
A device incorporating two or more check valves and an automatically
operating differential relief valve located between the two checks,
two shutoff valves and equipped with necessary appurtenances for testing.
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.
B.
At cessation of normal flow, the pressure between check valves
shall be less than the supply pressure. In case of leakage of either
check valve, the differential relief valve shall operate to maintain
this reduced pressure by discharging to the atmosphere. 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.
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. The enclosure must be self-draining, so that the
large amount of water which the relief valve may vent will be disposed
of reliably without submergence of the relief valve. This device must
also be approved as a complete assembly.
AUXILIARY SUPPLY
Any water supply on or available to the premises other than
the approved public water supply.
BAROMETRIC LOOP
A loop of pipe rising approximately 35 feet at its topmost
point above the highest fixture it supplies.
CERTIFIED BACKFLOW PREVENTION DEVICE TESTER
A person who is examined annually by the water purveyor and
found competent for the testing of backflow prevention devices. He
shall be provided with an appropriate identification card which must
be renewed annually. Failure to perform his duties competently and
conscientiously will result in prompt withdrawal of his certification.
CROSS-CONNECTIONS
Any 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 equally safe, wholesome and potable for human consumption.
WATER SUPERVISOR
The consumer or a person on the premises charged with the
responsibility of complete knowledge and understanding of the water
supply piping within the premises and for maintaining the consumer's
water system free from cross-connections and other sanitary defects,
as required by regulations and laws.