Prodigy HDLV Generation II Pump, Pump Manifold, and Circuit Board
6
Part 1081195-11
E
2018
Nordson Corporation
Purging
See Figure 5. When the operator initiates a color
change, the pump goes through a three-stage
purge process.
Stage 1: Soft Purge to Spray Gun
The suction pinch valves close, while the delivery
pinch valves remain open. Pump assist air
pressure turns on, starting at a low pressure and
building up to maximum pump assist pressure.
The air dispenses powder out of both fluidizing
tubes, through the powder delivery tubing and
spray gun and out into the booth.
Stage 2: Soft Purge to Feed Source
The suction pinch valves are open, while the
delivery pinch valves close. Pump assist air
pressure turns on, starting at a low pressure and
building up to maximum pump assist pressure.
The air dispenses powder out of both fluidizing
tubes, through the powder suction tubing, and back
into the powder feed source.
Stages 3 and 4: Hard Purge to Spray Gun
and Feed Source
The delivery pinch valves open. Pump assist air
pressure turns on at maximum pressure, while
pulses of line air pressure are sent down the purge
air fittings at the tops of the fluidizing tubes. The
pulses of air remove any powder that remains in
the pump, spray gun, and suction and delivery
tubing.
After the delivery side is purged, the delivery pinch
valves close and the suction pinch valves open.
The suction side is purged in the same way as the
delivery side.
Stage 1
Air
Powder
Stage 2
Air
Powder
Stages 3 and 4
Powder
Air
Air
Figure 5
Purging Operation
