PC 715 — Backwater Valves

Section PC 715: Backwater Valves

715.1 Sewage backflow. Where fixtures, floor drains, or area drains are subject to overflow as the result of backwater from the public sewer system, accessible backwater valves shall be installed in the fixture drain pipe from such fixture, in the branch drain to such area drain or group of fixtures, or in the building drain at its point of exit from the building and downstream from the building trap. Buildings located in flood hazard areas shall be deemed to be subject to overflow as the result of backwater from the public sewer system and shall be provided with backwater valves in accordance with the additional requirements of Section 7.3.3 of ASCE 24 as modified by Appendix G of the New York City Building Code. 715.2 Material. Bearing parts of backwater valves shall be of corrosion-resistant material. Backwater valves shall comply with ASME A112.14.1, CSA B181.1 or CSA B181.2. 715.3 Seal. Backwater valves shall be so constructed as to provide a mechanical seal against backflow. The flap shall be so designed as to hang partially open when not subject to backwater pressure. 715.4 Diameter. Backwater valves, when fully opened, shall have a capacity not less than that of the pipes in which they are installed. 715.5 Accessibility. Backwater valves shall be installed so that access is provided to the working parts for service and repair. Masonry access manholes shall be provided when the centerline of any drain line is 18 inches (457 mm) or more below a slab on grade.