The 1/4" Watts Series 009 Reduced Pressure Zone Assemblies are Watts "contractor grade" RPZ device. They began production in 1992 and still are being manufactured. The 009 features a one cover design and is constructed of bronze and use check modules that slide into the body and are held in place with a retainer. The relief valve assembly slides down between the retainer and is directly under the cover. The check modules and relief valve assembly come apart for service. No special tools are required for servicing 009 Series devices.
The 1/4" Watts 919 Series Reduced Pressure Zone Assemblies began production in 2003 and are still currently being produced. The 919 is a bronze bodied device with three covers. Check valves are poppet style and the relief valve is a stem type. Springs are not contained and covers will have tension, use caution when servicing. In 2010, the LF919 was introduced to comply with the new "Lead Free" laws. All repair parts were converted to lead free in 2013. Lead free repair parts will fit both regular 919 and lead free LF919 models. All 919 models have replaceable seats and require no special tools for repair.
The 1/4" Watts Series SD-2 Dual Check Valves prevent the reverse flow of contaminated water, such as carbon dioxide gas and carbonated water, from entering into the potable water supply due to backpressure backflow. It consists of a stainless steel body construction with internal rubber components and is designed for continuous or intermittent pressure applications. Commonly found on tea and coffee makers this backflow carries the ASSE 1032 certification but does NOT carry the ASSE 1022 certification.
The 1/4" Watts Series SD-3 Dual Check Valves with Atmospheric Port & Strainer for Carbonated Beverage Machines prevent the reverse flow of polluted water, such as carbon dioxide gas and carbonated water, from entering into the potable water supply due to backpressure backflow. It consists of stainless steel body construction with internal rubber components and is designed for continuous or intermittent pressure applications. Series SD-3 has an atmospheric port that provides visual indication of failure of the second check and a wye pattern strainer. Commonly found on carbonated beverage machines and coffee makers it has the ASSE 1022 approval required for such devices.