USC Foundation

List of Approved Backflow Prevention Assemblies

Updated 4/1/2024

Shutoff Valve Designation

The backflow prevention assemblies shown on this list have been evaluated with a specific set of shutoff valves as an integral part of the assembly. The specific shutoff valves are coded by a parenthetic code shown with each assembly. This coding of shutoff valves is defined below. Other shutoff valves having similar performance characteristics which permit the assembly to comply with the standards are also shown immediately after the original shutoff valves. The use of any shutoff valve on a specific assembly, other than those listed for that specific assembly invalidates the Approval. Assemblies listed with a Y in the “spare parts only" column may not include the shutoff valve designation.