The new Apollo® 4SG Series double check valves and double-check detector assemblies combine a short lay length with consistently low pressure loss and a flat flow curve, making them a suitable design for any piping system. Sized from 2-1/2” to 8”, the Apollo 4SG assemblies feature grooved end connections that reduce weight and length. They also allow for the use of lightweight grooved-end butterfly valves as shut-offs. OS&Y or NRS gate valves, with either grooved or flanged end connections, are also available. Apollo 4SG devices employ patented modular check and feature reversible EPDM seat discs. Maximum working pressure for the 4SG Series is 175PSI; operating temperature range is 33 to 140F. The series is manufactured in the USA in ISO 9001:2001 registered facilities.