Round sight glass sheet Gasket Sheet, Gauge Glass, Level Gauge, Quartz Glass, Sight Glass For compressive stress with temperatures borosilicate circular sight glass up to max. 280 degrees Celsius, In a toughened form, temperatures up to 315 degrees Celsius are possible whilst annealed glass may be used up 400 degrees Celsius continuously with a short term maximum of 500 degrees Celsius. Product Presentation…