Processing Magazine

Chemical company finds safer sight glass

December 4, 2006

A large chemical company experienced a major failure with a sight glass on a media vessel. The glass failed under surprisingly low pressure, and tragically resulted in an employee losing sight in one eye. The company knew it must act quickly to prevent similar misfortunes from occurring in the future. Eliminating all the sight glasses on their process equipment was not an option because they needed to visually inspect their fermentation process. The company established a task force to look into the occurrence and find an appropriate solution as quickly as possible. The committee’s goal was to search for a type of sight glass that was able to insure uninterrupted operation, easy to install, visually clear, and above all else – extremely safe!

The company committee researched and tested several sight glass assemblies to determine their ability to withstand various process applications. Most of these tests, however, revealed a vulnerability to failure even under low-pressure circumstances. In addition, these tempered, flat glass discs were not certified as removable or reusable. As the research committee continued its research, it learned of a unique alternative to conventional sight glasses, known as “fused” glass. The committee immediately contacted L.J. Star Incorporated, based in Twinsburg, Ohio. Considered to be an authority in this technology, employees of L.J. Star met with the committee to determine their exact requirements.

After gaining a full understanding of their needs, L.J. Star experts recommended its Metaglas® sight glass. Created through a process of melting glass inside a metal ring to establish mechanical pre-stressing, this fused sight glass provided a significant safety advantage over conventional tempered glass discs. It could withstand extreme pressures and was impact resistant. It also provided uninterrupted and efficient operation of their process equipment. Finally, by virtue of its design, it was easy to install, easy to remove, and able to be reused. Added up, these factors meant the company would save time and money.

In addition to inspecting every tank to insure correct sizing, L. J. Star developed and presented an awareness and maintenance program for the introduction of the new sight glasses to all of the company’s operators who worked with tanks and pressure vessels. Best of all, the solution produced a one-time material savings for the company in excess of $150,000 – not including the savings resulting from prevention of employee accidents, lost time, and product loss.

About L.J. Star

L.J. Star Incorporated provides an extensive line of process observation equipment -- sight glasses, lights, sanitary fittings, and level gage instrumentation. Product lines include Metaglas® Safety Sight Windows, Lumiglas® Explosion Proof Lights and Cameras, Visual Flow Indicators, Sight Ports, Sanitary Clamps, Magnetic Level Gages and Gage Glass. For additional information, contact L.J. Star Incorporated, P.O. Box 1116, Twinsburg, OH 44087. Phone: 330-405-3040. Fax: 330-405-3070. Email: view@ljstar.com. Website: www.ljstar.com.