Model D Rev D Pressure Reducing Regulator For General Service; 1/2" Line Size; Carbon Steel Body And Spring Chamber; S7 Trim: 316 Stainless Steel With PTFE Seat And Fluorocarbon Elastomer (FKM) Diaphragm; Mates With ASME 150 Flanged End Connections (14" Face To Face); 30-80 PSI Range Spring; Opt-4: Piston Stabilizer For Gaseous Service; Polyethylene Vented Spring Chamber Plug