Resources

Usage Guidelines

Handling Quartz Glass

It’s important to not contact fused quartz ware with bare hands because the salts in the skin contain alkali metal elements that can speed devitrification. Wear clean, cotton gloves or powder-free latex gloves when handling.

Cleaning

Fused quartz should be cleaned before being used. This can be done by placing it in a 7% maximum solution of Ammonium Bifluoride for no more than 10 minutes, or a 10% volume maximum solution of Hydrofloric Acid for no more than five minutes. Fused quartz should then be rinsed in deionized or distilled water and then dried.

Running In Procedure

An even layer of cristobalite needs to be formed on the O.D. of quartz tubes to increase resistance to devitrification and sag. Expose a new tube to a temperature of up to 1200°C and rotate it 90° every two hours for the first 12 to 24 hours.

Storing Quartz

The original shipping container is the best option for storing fused quartz. The next best option, if there isn’t space for the shipping container, is to keep the original wrapping. With quartz tubing, the end coverings should remain in place until usage. This will protect the ends from chipping while also keeping the tubes free from dirt and moisture that can alter the tube’s performance.

Furnace Insertion

Quartz and silica glass need to remain away from heating elements and flames. While they have low thermal conductivity, they can develop cracks if locally heated. Long quartz tubes can deform at temperatures at or above 1100°C. It is important to support both glass types.

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Joining Fused Quartz and Other Materials

Compared to other materials, quartz and silica glass will expand just slightly with increases in temperature. To avoid cracks developing when these glass products are connected to other materials, it is important to be careful.

Devitrification

Devitrification typically starts when the temperature rises to 1200°C or higher. It can occur at temperatures of 1000°C or less if there are impurities on the surface. Devitrification of quartz and silica glass is the transition from a metastable (vitrified) state to a stable crystallized state of cristobalite.

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