4-65
4.8 Igniting and Extinguishing the Flame
AA-6800/6650 Instruction
CAUTION
1. Always use high temperature burner head when using a nitrous oxide-acetylene flame. Using the
standard burner head with this gas causes a danger of flashback.
2. When the acetylene flow rate is high, carbon is deposited around the burner slot. When this occurs, use
the provided large screwdriver to scrap off the carbon deposit while taking care about the following
points.
• Insert the screwdriver at the center on the burner slot while keeping the top portion of the
screwdriver lengthwise. Don't close a large part of the burner slot by keeping the top portion
of screwdriver horizontally.
• While keeping the top portion of screwdriver lengthwise, slide it from the center to the
outside (right or left side) and scrap off the carbon deposit gently. To prevent the flame from
going out, don't slide the screwdriver from the outside to the center. Insert it at the center
again and scrap off to the outside.
• Be careful not to scratch the burner head and slot.
• Remove the carbon deposit inside the burner slot using a piece of hard paper, after the
flame is extinguished and the burner is completely cooled.
Figure 4.45 Removing Carbon Deposit in N
2
O-C
2
H
2
Flame
3. When using a nitrous oxide-acetylene, decreasing the acetylene or increasing the nitrous oxide will
cause the pink portion of the flame (red feather) to gradually decrease. If this decreases to less than
2 mm, the flame will split, and if the acetylene flow is further reduced, a flashback may occur.
Figure 4.46 N
2
O-C
2
H
2
Flame
Carbon deposit
High temperature burner head
Blue
Pink (Red feather)
Dark blue
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