Gas Burner

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Lighting the Burner
Adjusting the Burner
Extinguishing the Burner
Additional Topics
Safety 2
Heating Solutions
Heating a test-tube
Holding an Object While Heating

Adjusting the Burner


Video. Adjusting the flame on the gas burner

Video. Soot on the test tube

Video. Adjusting the flame

The burner has two controls used to adjust the flame.

The Gas Control Needle Valve is used to adjust the height of the flame.

  • The needle valve should never be closed completely – it is a flow control only and can be damaged (the needle gets bent) if closed completely.
  • Shut off the gas at the wall/bench (see next page in this module) to extinguish the burner.

The Air Control Vent is opened by turning the burner tube. This allows increasing amounts of air to mix with the gas before combustion, leading to a hotter flame. There are 3 different recognizable flames:

Cool Yellow flame

  • a highly visible flame at ~200°C
  • not used for heating objects because it deposits soot on them
  • good setting for lighting the burner
  • a temporarily unused burner should be left at this flame setting

Medium Blue flame

  • has a uniform blue color
  • approx. 700 °C
  • can be hard to see
  • used for heating solutions/liquids in glass containers (test-tubes, flasks, beakers)
  • used when “flame drying” glassware

Roaring Blue flame

  • has a light blue, triangular inner cone and curved blue outer cone
  • hottest spot is just above the tip of the inner cone, >1000°C
  • region inside the light blue cone is cool, unburned gas
  • used for direct heating of ceramic crucibles
  • used for indirect heating of glass beakers and flasks supported on a wire gauze
  • not used for direct heating of glass containers as it creates localized “hot spots” which lead to “bumping” of solutions and/or cracking of glassware