Economical Hermetic Sealing of Rayotek Sight Windows' Threaded Sight Glasses

The function of NPT and SAE threaded sight glasses is to provide visual accessibility for observation of closed and sealed systems, where a robust, long-lasting hermetic seal is critical to performance.  Rayotek Sight Windows' proprietary technologies for sealing optical materials to metal economically make high pressure and ultra-high pressure windows both reliable and affordable.

Rayotek Sight Windows' NPT and SAE sight glass windows utilize glass, fused silica, fused quartz, sapphire and other clear materials sealed into a corrosion-resistant metal housing to form a hermetically-sealed, durable product.

Notes Bill Raggio, President and CTO of Rayotek Sight Windows, "a huge advantage of our NPT and SAE threaded sight glasses is that they have a long working life with virtually no maintenance required other than routine cleaning – this saves the user significant labor costs.  In addition, they operate in high purity, ultra-high vacuum, clean room rated systems, with virtually no contaminants or outgassing to most systems."

Rayotek Sight Windows' NPT and SAE sight glasses are used in industries including petroleum, natural gas, pulp and paper mill, marine, deep sea, aerospace and medical sectors.  They are used for visual accessibility in a variety of otherwise unpleasant and/or dangerous locations, such as:

  • high pressure tanks

  • hydraulics

  • flame and explosion chambers

  • furnaces

  • hazardous systems

  • supercritical systems

  • sanitary, pharmaceutical and food processing systems

  • ultra-high pressure and vacuum systems.

Engineered, manufactured and tested to ISO 9001:2008 standards in a US facility, Rayotek Sight Windows' NPT and SAE sight glasses are particularly resilient in extreme thermal, mechanical, chemical and pressure settings. 

About Rayotek Sight Windows.

Rayotek Sight Windows is the end result of a natural evolution of business and technology that began at the parent company, Rayotek Scientific, Inc. As an international leader in glass, sapphire and materials integration technology, Rayotek Scientific had received numerous requests to engineer and manufacture long lasting, high-end sight windows for hostile environments with rigorous requirements and safety restrictions.  Rayotek Sight Windows is unique in its extensive and diverse staff of engineers and technicians that understand, intimately, how sight windows work, and more importantly, how they will work with your application.  Rayotek Sight Windows is ISO 9001:2008 certified and offers extensive FEA, simulation, modeling and testing expertise to support the windows.

Rayotek Sight Windows

a division of Rayotek Scientific, Inc.

11495 Sorrento Valley Road

San Diego, CA 92121

Technical Contact: 

Bill Raggio or his engineering team


or this form

Press Contact:

Mona Zemsky


cell 773-600-7740

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