18-29-606.5.1.1.2 Compression tank.

   Each compression tank shall be so connected that the air content thereof shall be no less than 25 percent of its total capacity. Each compression tank shall be provided with a sludge drain pipe which shall be connected to such tank at the lowest level of the bottom section thereof and shall discharge through an indirect connection into the drainage system with a minimum air gap of 6 inches (150 mm).

18-29-606.5.1.1.3 Sludge drain pipe.

   Each sludge drain pipe shall be equal in size to the inlet pipe but need not exceed 2 inches (50 mm) and shall be provided with a control valve having a clear waterway equal in area to that of the sludge drain pipe.

18-29-606.5.1.2 Booster pump system.

   Booster pump systems may be of the constant speed type or the variable frequency drive type. Each pump or pumps shall have sufficient capacity to furnish an adequate supply of water for any purpose. When one pump is installed it shall run continuously or when a multipump system is installed the lead pump shall run continuously. A pressure reducing valve shall be installed on the discharge side of each constant speed pump.

18-29-606.5.1.2.1 Gravity tanks.

   Gravity tanks operating at atmospheric pressure shall be installed as required by Section 18-29-606.5.4.

18-29-606.5.1.2.2 Total pressure.

   The water piping system and equipment supplied by the systems enumerated in this section shall be capable of withstanding the total pressure developed by any such system at any elevation in which these pressures occur.

18-29-606.5.1.2.3 Low pressure cutoff.

   When a pump is directly connected to a city water main, a low pressure cutoff switch on the pump shall be installed to prevent the creation of pressures less than 5 psi (35 kPa) on the suction side of the water system and within 5 feet (1525 mm) of the pump suction inlet, and a pressure gauge shall be installed between the shutoff valve and pump.

   Exception: Fire pumps.

18-29-606.5.2 Surge tank for pumps.

   When a water system in any building, structure or premises is supplied with other than city water or is equipped for service other than from the city mains or which is supplied with city water which has been previously used for any purpose, each service from the city water system shall enter through a receiving tank for the purpose of preventing water from the secondary system from flowing back into the city mains.

18-29-606.5.3 Check valves required.

   Check valves which are noiseless in their operation and air chambers of sufficient air cushion capacity shall be installed in the suction pipe and the discharge pipe of each house pump, or other water pressure increasing device. Where such check valves are of the slow-acting type and the operation thereof entirely eliminates the shocks, strains, stresses, and excess noises caused by the operation of such pump or device, the installation of air chambers may be dispensed with.

18-29-606.5.3.1 Approval required.

   No check valve shall be installed unless the design and construction thereof shall first have been approved by the Commissioner of Buildings or Commissioner of Water Management.

(Amend Coun. J. 11-8-12, p. 38872, § 352; Amend Coun. J. 10-14-21, p. 37722, Art. VI, § 24)