Watts 994 is a reduced pressure assembly. Production began in 1998. In 1997 the Watts Company purchased the Ames Company and began marketing the Ames 4000 SS as the Watts 994. The body is made of stainless steel with a single access cover. The check design is modular. In the 2 1/2"-6" size the check assemblies are not field repairable and the whole check module must be replaced for repair. The check is made of glass filled Noryl and is cam operated. The relief valve is attached to the check body by threads and uses an external sensing line.