Our sight glass is ready for installation on existing ANSI or DIN standard flanges. This bolt-on sight glass unit consists of a base with a raised face flange to fit standard ANSI Class 150 flange nozzles. Sizes range from 2 to 8″ and all conform to ASTM standards. The glass disc, either borosilicate or quartz, is clamped in place by a gasketed glass retainer held by threaded bolts. For added safety, use a Metaglas Safety Sight Glass disc in place of the conventional glass. Other options include lights, such as the LumiStar1000, Wiper Type I, and a spray ring.