16E / 16E-H / 16E-P Spray Gun
20
MAN 96150 EN 01
2.3
Principles of Operation
2.3.1 Mechanical Operation
Except for combustion, all functions of the spray gun are powered by
air pressure and flow. Air pressure drives the turbine and wire drive
mechanisms, enables the wire grip mechanism to feed the wire, cools
the nozzle and air cap and propels the atomized material onto the
workpiece surface. It is essential that proper air pressure and flow be
maintained to the spray gun during operation.
Once the turbine is up to speed, the drive shaft and lower drive roll and
gear are turning. The speed of the turbine is controlled by rotating the
control ring as indicated (i.e.,
FASTER
,
SLOWER
). Opening the wire
feed valve on the handle actuates the wire grip mechanism. This
engages the upper and lower drive gears to grip and feed the wire.
The wire extends beyond the front of the air cap where it is fully melted
and sprayed.
2.3.2 Combustion
The oxy-fuel gas does not have enough energy, even after combus-
tion, to propel the melted material. When the spray gun is initially lit
(with the gas head valve in the lighting position), there is no air flowing
to the front end. Immediately after the gas is lit, the gas head valve is
set to the run position. In the run position, the oxygen and combustion
gases flow at optimum levels for sustained combustion and air flows to
the air cap. The air flow to the air cap maintains an air envelope
around the flame and the melting wire. The air envelope cools the front
end parts, prevents loading of material on the air cap and propels the
melted material onto the substrate.
16e_cutaway
Air
Oxy-
Wire
127 mm (5”) Minimum
203 mm (8”) Maximum
Air Cap
Body
Nozzle
Air Cap
Air Envelope
Melting Wire
Characteristic
luminous white
cone of balanced
oxy-acetylene flame
Substrate
Sprayed Material
Atomized Spray
Fuel