Model D Rev D Pressure Reducing Regulator For General Service; 3/4" Line Size; Carbon Steel Body And Spring Chamber; S40 Trim: 316 Stainless Steel Metal Seat With Neoprene (BC) Diaphragm; Mates With ASME 150 Flanged End Connections (14" Face To Face); 2-15 PSI Range Spring; Opt-4: Piston Stabilizer For Gaseous Service; Polyethylene Vented Spring Chamber Plug; Opt-40: NACE Construction Per MR0175