Direct connection of sprinklers to a city water main shall be acceptable as an automatic water supply, provided the main is capable of maintaining a pressure of at least fifteen psig at the top of the highest sprinkler riser, with five hundred gpm of water flowing from a two and one-half inch hydrant outlet located at the street level within two hundred fifty feet of the building. The hydrant test shall be made between the hours of eight a.m. and five p.m. on a working day. If the pressure found in this test is insufficient to comply with the above requirement, a minimum of twelve psig at the top of the highest sprinkler riser shall be acceptable, provided that all piping in the affected area and supply piping thereto that is four inches and under is increased one pipe size above those sizes required by reference standard RS 17-2, RS 17-2A or RS 17-2B, as applicable. In addition to the fifteen psig or twelve psig requirements, the following requirements shall be met.
(a) The size of each connection shall be as large as that of the main riser and, except in sprinkler systems in multiple dwellings, shall be at least three inches and shall be controlled by an accessible shutoff valve.
(b) The service pipe shall be flushed out thoroughly before connecting to the sprinkler system. A flow sufficient to produce a water velocity of at least five fps shall be used.
(c) Each service shall be equipped, under the sidewalk, with a control valve in a flush sidewalk box located within two feet of the front wall of the building or street line as required by the department of environmental protection. The location of the control valve shall be indicated by a sign placed on the structure directly opposite the sidewalk flush box, and such sign shall have a white background with one inch red letters reading: "Automatic Sprinkler Shutoff Valve . . . Feet Opposite This Sign." Alternatively, brass, bronze, or other metal sign with one inch letters, raised or counter-sunk one-eighth of an inch may be used.
(d) The plans submitted in connection with the permit application shall be accompanied by a statement from the bureau of water supply of the department of environmental protection, stating the size of street main or mains, distance to and size of mains from which it or they are fed, the location of control valves, the static pressure on the hydrant nearest the premises, and the residual pressure in the street main taken on a hydrant near the premises when the flow from the nearest hydrant is equal to the flow required to meet the requirements of this section. A letter from the bureau of water supply of the department of environmental protection estimating available flow and residual pressure shall be acceptable to the borough superintendent when a hydrant test cannot be conducted.
Editor's note: For related unconsolidated provisions, see Appendix A at L.L. 1999/010.