(a) Protective devices in general. The owner or occupant of every premise receiving water supply shall apply and maintain suitable means of protection of the premise supply, and all appliances thereof, against damage arising in any manner from the use of the water supply, variation of water pressure, or any interruption of water supply. Particularly, such owner or occupant must protect water-cooled compressors for refrigeration systems by means of high pressure safety cutout devices. There shall likewise be provided means for the prevention of the transmission of water ram or noise of operation of any valve or appliance through the piping of their own or adjacent premises.
(b) Relief valves. On all “closed systems” (for example, systems having a check valve, pressure regulator, or reducing valve, water filter, or softener) an effective pressure relief valve shall be installed either in the top tapping or the upper side tapping of the hot water tank, or on the hot water distributing pipe connection at the tank. A one-half inch drain pipe shall be connected to the relief valve for discharge on the floor or into a sink or open drain through an air gap. No stop valve shall be placed between the hot water tank and the relief valve or on the drain pipe. (See applicable village plumbing codes.)
(c) Air chambers. An air chamber or approved shock absorber shall be installed at the terminus of each riser, fixture branch, or hydraulic elevator main for the prevention of undue water hammer. The air chamber shall have a diameter not less than that of the pipe it serves and a length not less than 15 diameters of said supply pipe. Where possible, the air chamber should be provided at its base with a valve and rain cock for water drainage and replenishment of air.
(Prior Code, § 9-1-49)