18-29-604.6 Variable street pressures.

   Where street water main pressures fluctuate, the building water distribution system shall be designed for the minimum pressure available.

18-29-604.7 Inadequate water pressure.

   Wherever water pressure from the street main or other source of supply is insufficient to provide flow pressures at fixture outlets as required under Section 18-29-604.3, a water pressure booster system conforming to Section 18-29-606.5 shall be installed on the building water supply system.

18-29-604.8 Water pressure reducing valve or regulator.

   Where water pressure within a building exceeds 100 psi (690 kPa) static at any fixture or outlet, an approved water pressure reducing valve conforming to ASSE 1003 with strainer shall be installed to reduce the pressure at any fixture or outlet in the building water distribution piping to 100 psi (690 kPa) static or less.

18-29-604.8.1 Reserved.

Editor's note – Coun. J. 12-14-22, p. 58278, Art. VI, § 8, as corrected by Coun. J. 4-19-23, p. 62477, § 1, repealed § 18-29-604.8.1, which pertained to valve design.

18-29-604.8.2 Repair and removal.

   All water pressure reducing valves, regulators and strainers shall be so constructed and installed as to permit repair or removal of parts without breaking a pipeline or removing the valve and strainer from the pipeline.

18-29-604.9 Water hammer.

   The flow of velocity of the water distribution system shall be controlled to reduce the possibility of water hammer. An air chamber or water-hammer arrestor shall be installed where quick-closing valves are utilized. Water-hammer arrestors shall be installed in accordance with the manufacturer's instructions. Water-hammer arrestors shall conform to ASSE 1010. Air chambers shall comply with Section 18-29-604.9.1.

(Amend Coun. J. 10-14-21, p. 37722, Art. VI, § 12; Amend Coun. J. 12-14-22, p. 58278, Art. VI, § 9; Amend Coun. J. 4-19-23, p. 62477, § 1)

18-29-604.9.1 Air chambers.

   An air chamber that is installed in a fixture supply shall be 12 inches (304.8 mm) in length and the same diameter as the fixture supply, or an air chamber with an equivalent volume may be used. An air chamber that is installed in a riser shall be 12 inches (304.8 mm) in length and at least the same diameter as the riser.

(Added Coun. J. 12-14-22, p. 58278, Art. VI, § 9)

18-29-604.10 Size of water supply pipes.

   Each main supply pipe, principal supply pipe, branch supply pipe, riser pipe, distributing pipe, or branch distributing pipe shall be sized in accordance with this section.

(Amend Coun. J. 10-14-21, p. 37722, Art. VI, § 13)

18-29-604.10.1 Minimum sizes of branch distributing pipes for fixtures and appliances.

   The water supply system shall be designed on the basis of the minimum available pressure at the water main or other source of water supply. The minimum available pressure will be given by the department of water management for each location.

(Amend Coun. J. 11-8-12, p. 38872, § 350)