The Multiplex 19-0897 is a specialized ASSE 1022-certified backflow preventer designed specifically for carbonated beverage systems. Its primary function is to protect upstream copper and brass plumbing from the corrosive effects of CO2-saturated water (carbonic acid). This assembly utilizes a dual-check valve system with an atmospheric vent to ensure that carbonated water from a soda carbonator cannot migrate back into the potable water supply.

Featuring a 3/8" Male NPT inlet and a 3/8" Male Flare (MFL) outlet, this unit is engineered for seamless integration between the water supply line and the carbonator pump. It is constructed with a lead-free brass body and a stainless steel discharge retainer, rated for pressures between 10 and 200 PSI. If the primary check valve becomes fouled, the integrated vent allows the acidic mixture to exhaust safely through a 1/4" barb fitting rather than entering the main water line.

Why Replace This Component?
Backflow preventers are mechanical wear items that must be replaced if they begin to constantly leak or "spit" water from the vent port. This usually indicates that the primary check valve is stuck open due to mineral scale or debris. Because these are critical for health code compliance, a failing unit can lead to failed inspections or the contamination of a building's freshwater system, which can cause lead leaching in older copper pipes.