Sight Glass Industries & Applications

The term “sight glass” applies to a window used to see the fluids or bulk solids within industrial process piping, reactors, or storage tanks. They are sometimes referred to as “viewports,” “sight ports,” or “flow sights,” especially when incorporated with a mounting system. These components are critical for safety, quality, and process control in a wide variety of industries such as: 

  • Chemical Processing
  • Energy/Utilities
  • Pulp and Paper
  • Oil refineries
  • Steelmaking/Smelting
  • Biofuels
  • Pharmaceuticals
  • Food & Beverage

Sight Glass Materials

Sight glass can be fabricated from a number of materials including soda-lime glass, borosilicate glass, and fused silica/quartz. Material selection depends on the expected conditions regarding temperature, pressure, and process material.  A given sight glass may be subjected to thermal shock, corrosive chemistries, abrasive wear, and impacts.  These conditions must be taken into consideration in the design phase.

At Cincinnati Gasket & Industrial Glass, we manufacture sight glasses in the following materials:

  • Soda-Lime Glass (annealed or tempered)
    • Versatile and inexpensive. Used in a wide range of applications
    • Stock thickness from 1/8″ to ¾”+
  • Borosilicate Glass (annealed or heat strengthened)
    • Resistant to thermal shock
    • More optically clear than soda-lime
    • Stock thicknesses from 0.7 mm to 1-1/2”+
  • Fused Quartz (GE124)
    •  Very high resistance to heat and thermal shock
    • Excellent UV transmissivity
    • High chemical resistance
    • Cut from boules in thickness to 2″ +
  • Laminated Glass
    • High impact resistance

If you need assistance in determining the right material and thickness selection for sight glass fabrication, please describe your application here and one of our sales associates will be happy to help.  When describing your application, please provide as much information as you can regarding:

  • Temperature
  • Pressure
  • Material characteristics (Corrosivity/pH Range & Abrasiveness )
  • Expected impacts (internal and external)
round slight glass