HEAT RESISTANT SIGHT GLASSYou can put an end to your problems with broken sight glasses and protect the reputation of your brand by using our Sight Glasses made of Ceramic Glass. Ceramic Glasses are of EC origin with ISO 9001 certificate. These glasses Are durable to heat shock tests up to 700 degrees Celsius and used as Sight glasses (observation port glass) by boilermakers all over the world. In the past, tempered (toughened) soda-lime glass (ordinary window glass) was used. But due to the fragile characteristic of Soda-lime glass, the sight glasses on the observation port was broken in time. With the introduction of Ceramic Glass to this market, all the problems with broken Sight Glass is solved. Please visit our web site and enter the section High-Tech GlassTo have better idea about the ceramic glass. If you are interested in this product, please contact us and we shall be glad To send out free samples to you.