Minimum acceptable criteria for installation of backflow prevention assemblies, or other devices requiring regular inspection and testing by this chapter, shall include the following.
(A) All backflow prevention devices shall be installed in a horizontal run of pipe. No vertical installation of backflow prevention devices shall be allowed unless such device is approved for such installation by the University of Southern California Foundation for Cross-Connection Control and Hydraulic Research and the state’s Department of Environment and Conservation, Division of Water Supply, approved list.
(B) Installation of backflow prevention devices shall be performed only by persons certified by the state and has the authority from the water purveyor. For all backflow prevention devices installed on a fire protection system, the installers must have a state contractor’s license. Evidence of current certification/license must be on file, with the cross-connection control office before any installation or testing of the device can be done.
(C) All devices shall be installed in accordance with the manufacturer’s installation instructions and by the state installation guide; from the state’s Manual on Cross-Connection, unless such instructions are in conflict with this chapter. If conflicting instructions, this chapter adds that all devices possess test cocks and fittings required for testing the device. All test cocks will be fitted with caps and all fittings shall permit direct connection to test devices used by the Department.
(D) The entire assembly including test cocks and valves shall be easily accessible for testing and repair, and shall meet all confined space requirements of OSHA/TOSHA.
(E) Reduced pressure backflow prevention devices shall be located so that the relief valve discharge port is a minimum of 12 inches, plus the nominal diameter of the supply line, above the ground floor surface. Maximum height above the floor surface shall not exceed 60 inches.
(F) Clearance of devices from wall surfaces or other obstructions shall be a minimum of six inches; or, if a person must enter the enclosure for repair or testing, the minimum distance shall be 24 inches.
(G) Devices shall be protected from freezing, vandalism, mechanical abuse and from any corrosive, sticky, greasy, abrasive or other damaging substance.
(H) Devices shall be positioned where discharge from a relief port will not create undesirable conditions. An approved air-gap shall separate the relief port from any drainage system. Such air-gap shall not be altered without the specific approval of the Department.
(I) Devices shall be located in an area free from submergence or flood potential.
(J) All devices shall be adequately supported to prevent sagging.
(K) An approved strainer, fitted with a test cock, shall be installed immediately upstream of all backflow devices or shut-off valves, except on fire lines, using only non-corrosive fittings (e.g., brass or bronze) in the device assembly.
(L) Gravity drainage is required on all installations. Below ground installations shall not be permitted.
(M) Fire hydrant drains shall not be connected to the sanitary sewer, and fire hydrants shall not be installed in such manner that back-siphonage or backflow through the drain may occur.
(N) Where jockey (low volume-high pressure) pumps are utilized to maintain elevated pressure, as in a fire protection system, the discharge of the pump shall be on the downstream side of any check valve or backflow prevention device. Where the supply for the jockey pump is taken from the upstream supply side of the check valve or backflow prevention device, a backflow prevention device of the same type(s) required on the main line shall be installed on the supply line.
(O) Fixed position, high volume fire pumps shall be equipped with a suction limiting control to modulate the pump if the residual line pressure reaches 20 psi. If line pressure drops below 20 psi, the pump will shut off to protect the distribution system. This shut off system must be tested annually for proper operation and a report of the test must be sent to the Office of Cross-Connection Control.
(2011 Code, § 18-311) (Ord. 06-45, passed 9- -2006)