Glass & Tubing for Level Gauges

Annealed Borosilicate - Clear
Good for normal service where one surface is heated to a maximum temperature of 446F (230C), using 1/4" or thicker glass. The temperature difference between ambient and process should not exceed 150F.

Tempered Borosilicate - Clear
Recommended for use where higher pressures are required than can be obtained with Annealed Borosilicate. Maximum service temperature is 500F (260C). No corrosion to surface, nor severe chill can be tolerated.

Cobalt Blue Furnace - Blue
Used to reduce glare when observing flame, smoke, and ash intensity in power plants and marine boilers. Thickness up to 1/4".

Vycor - Clear
Can be used continuously at 1652F (900C). The temperature difference between ambient and process surfaces should not exceed 600F. Thickness up to 1/2". Excellent optical properties.

Fused Quartz - Clear
For industrial and laboratory applications. Can be used continuously at 1742F (950C). Commercial Grade is standard. Optical Grade is available.

Pyroceram - Amber Tint
This transparent glass-ceramic material will not delaminate at elevated temperatures. Available in 5mm thickness only. Mainly used in furnaces.
  Glass For:
Furnaces, Ovens
Observation Equipment
Flow Indicators
Pressure Vessels/Tanks
Tempering greatly increases the strength of glass and helps it overcome the damaging effect of scratches and other surface defects. Glass is heated to a specified point above its annealing temperature, then quickly quenched causing the surface to shrink and harden. While the interior cools more slowly it tries to shrink, putting itself in tension and creating a compressive stress on the surface. When completed, the surface compression must be overcome and a tensile stress introduced before the glass can be harmed. Thus, the mechanical and impact strength as well as the thermal shock resistance are improved greatly.
Pressure Chart for Circles
Unsupported Diameter - inches
  Note: All Glass should be protected from thermal
  shock, and shielding is recommended.
Model Selection Table Adjust above
Model Type Color Shape Normal Service Rating F Pressures by the following:
530 Annealed Borosilicate Clear Circle 446 100%
531 Annealed Borosilicate Clear Rectangle 446 -
532 Cobalt Blue Furnace Blue Circle 446 100%
533 Cobalt Blue Furnace Blue Rectangle 446 -
534 Vycor Clear Circle 1652 75%
535 Vycor Clear Rectangle 1652 -
536 Quartz Clear Circle 1742 60%
537 Quartz Clear Rectangle 1742 -
538 Tempered Borosilicate Clear Circle 500 300%
539 Tempered Borosilicate Clear Rectangle 500 -
528 Pyroceram Amber Tint Circle 1292 -
529 Pyroceram Amber Tint Rectangle 1292 -

Catalog Page 43
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John C. Ernst Co., Inc.
Sparta, NJTel: 973-940-1600Fax: 973-940-1620
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Sparta, NJ 07871
Physical Address
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Sparta, NJ 07871