Redlands High School

Bunsen Burners

The Bunsen burner is a heat source that uses the mixing of a combustible gas (natural gas in the case of RHS) and oxygen from the air to produce a high temperature flame (up to 1500°C). There are many types of laboratory burners and many configurations for the Bunsen burner, but the basic RHS burner consists of the following:

• Air Inlet: Supplies air to the combustion area. The air inlet is controlled by raising the barrel (to allow more air) or lowering the barrel (to reduce air flow). When first lighting the burner, the air inlet should be almost closed.
• Barrel: Mixing chamber for gas and air.
• Base: Supports and stabilizes the burner.
• Gas Supply Line: Supplies gas to the burner from the bench top gas valve.
• Needle Valve: Supplies gas to the combustion area. Turning the valve clockwise closes the valve – turning it counter-clockwise opens the valve.

 Steps for lighting the Bunsen burner:

1. Make sure the bench nozzle is completely closed. The handle must be perpendicular to the nozzle direction. When the handle is parallel to the nozzle, the gas valve is open.
2. Connect the rubber hose to the nozzle firmly, but do not force the rubber end on to the nozzle – it may split.
3. Make sure the needle valve on the burner is closed and the barrel is lowered so that it is almost closed.
4. Open the bench nozzle. When using the burner, the bench gas supply should be fully opened. To regulate the gas flow through the burner, use the needle valve.
5. Open the needle valve two turns. You should be able to hear the gas flow through the burner.
6. Light a match and slowly run it up the side of​ the barrel until it ignites the gas. (This is done for safety. If the match was held directly over the barrel, a high flame could burn the hand.) Shake match out and place it in the match can.
7. Adjust the flame by raising or lowering the barrel until the flame has an inner blue cone with no orange color. (Too much air flow will blow the flame out.) The flame should be about 7 -8 cm tall. To adjust the flame height open or close the needle valve and readjust the barrel.
8. Once the flame is lit, it must be tended at all times. If you need to leave the burner, for any reason, extinguish the flame by turning the gas valve handle to the OFF position.