Dual Check Backflow Preventer

This Standard establishes performance requirements for dual check backflow preventers. These requirements include compliance testing for torque, deterioration at maximum rated temperature and pressure, hydrostatic leakage of check valves, flow and pressure loss, drip tightness of check valves, check valve operation, dual check valve integrity at maximum intermittent rated flow, and requirements for materials, repairability, and instructions for marking and installation.

Performance Requirements for Dual Check Valve Type Backflow Preventers for Carbonated Beverage Dispensers, Post Mix Type. These devices consist of two (2) independently acting check valves internally force loaded to a normally closed position and designed to operate under intermittent or continuous pressure conditions. These devices shall be permitted to be equipped with a supplementary check valve installed downstream of the independently acting check valves.

The California State Health and Safety Code Section 116875 requires that no person shall use any pipe, pipe or plumbing fitting or fixture, or solder or flux, that is not lead-free in the installation or repair of any public water system or any plumbing in a facility providing for human consumption except when necessary for the repair of leaded joint of cast iron pipe.

NSF/ANSI 61 addresses the human health effects of drinking water system components. This performance-based standard evaluates the amount of contaminants that leach from the products into potable drinking water. The origin for this standard was lead reduction/ removal. Any lead that elutes into the water at over 0.25% fails this standard.

NSF/ANSI 372 establishes a standardized methodology for the determination and verification of product compliance to minimize lead contaminants. This standard is consistent with the United States Safe Drinking Water Act (SDWA) and its lead-free plumbing requirements, as well as the requirements of individual U.S. states such as California.