METAGLAS^® History

Borosilicate Glass Fused To Stainless Steel

Herbert’s Industrieglas was in the business of glass making for more than 50 years; their main products included test tubes, beakers and other glass blown products. The family was also in the paint manufacturing business for many years, and just recently sold the paint works to Hoechst-Celanese. Because of their expertise in the glass and paint fields, the Herbert’s companies worked together to develop glass beads in paint. This new paint was used for reflective road stripes and road signs. During the 1970’s, Herbert’s decided to expand the glass products to include sight glasses for pressure vessels.

In the beginning, they offered conventional plain glass windows to the various chemical companies in Europe. Due to the risks involved with using conventional sight glass windows, Hoechst-Celanese contacted Herbert’s and asked them to develop a safer sight glass. At the beginning, Herbert’s proposed the commonly known styles of safety sight windows. Different designs were discussed, such as dual glass windows, windows with Plexiglas shields and glass with laminated wire or two pieces of glass laminated together. It was later determined that even though these designs offered a slightly higher degree of safety, the glass was still susceptible to failure. It was at this time that Herbert’s, in cooperation with Hoechst-Celanese, started to experiment with fusing glass to metal. Although this technology had been known for some time, it was primarily done with materials that were not suitable for the chemical processing industry. Because of the enormous costs involved in developing this new safety sight glass, Herbert’s was forced to ask Hoechst-Celanese for assistance. As time went by, and costs continued to mount, it was determined that more help in developing this product was required. Herbert’s, with the assistance of Hoechst-Celanese, then contacted Bayer AG and BASF. With the assistance in funds, testing, and technical help, these three large chemical companies became instrumental in helping develop what is known today as METAGLAS. Their reasons for assisting in the development were purely personal – they wanted safe sight glasses in their facilities, where there would be no risk of injury or failure. As the METAGLAS became more and more popular, it was decided that a DIN standard was needed for the process of manufacturing- Bayer AG helped write this standard, now known as DIN7079.

Since it’s beginning, METAGLAS has been known as the safest sight glass in the world. Other approvals on the METAGLAS include Factory Mutual, ATEX, Cenelec EEx, CE, Alberta Boilers Safety Association, Ontario Boilers and Pressure Vessels Safety Division, and Quebec Boiler and Pressure Vessel Act. METAGLAS is manufactured in accordance with TUV, ISO9001, AD guidelines WO/TRD 100 (European Technical Rules For Pressure Vessels) and ASME BPE-1997 (Bioprocessing Equipment).