Model "DA2" Differential Pressure Reducing Regulator (Series II)-PDRV; Body Size 2",Standard Diaphragm Construction; Ductile Iron Body & Spring Chamber,1/8" Petcock Vent; 17-4ph SST Trim, 316l SST Cage, Gf-Tfe Seat, Gylon 3-Ply Diaphragm,;Rtfe Static Seal, Pra+Wiper Dynamic Seal; Npt End Connection; 5-15 PSId Range Spring; Internal Sensing, Standard - Flow To Open Direction; With Special Double Tapped Spring Chamber,1-1/2" Npt