957ISR-LG

Series 957ISR-LG Reduced Pressure Zone Assemblies provide protection to the potable water system from contamination in accordance with national plumbing codes. Series 957ISR are normally used in health hazard applications for protection against backsiphonage or backpressure. This reduced pressure zone assembly shall consist of two independently operating torsion spring check modules, a differential pressure relief valve located between and below the two modules. The required torsion spring check modules and relief valve shall be contained within a sleeve accessible single housing constructed from 304 (Schedule 40) stainless steel pipe with groove end connections. Torsion spring checks shall have replaceable elastomer discs and in operation produce drip tight closure against the reverse flow of liquid caused by backpressure or backsiphonage. Available in sizes 100mm-250mm (4-10 IN).