Sight Glass Valve Sight Glass Valve Sight glass valve is suitable for light and heavy industry and building piping. Should you have any question about sight glass valve, please feel free to contact sight glass valve manufacturer-NTGD Request a Quote Sight Glass Valve Specifications Body MaterialWCB、304、321、316、316LGlass MaterialBorosilicate glassQuartz glassWork Temperature(℃)0℃~250℃0℃~550℃Nominal Pressure(MPa)<0.60.6 MPa ~2.5 MPaSeal MaterialNBR, PTFEConnection TypeNPT, FlangeRapid temperature change allowed(℃)<60