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800-556-3484 Sales and service of Nordson EFD dispensing systems are available worldwide.
781Mini Series Spray Valve
11
Service
Perform these service procedures as needed for the best valve operation. You will need the following tools:
• 0.035" hex wrench (included)
• 1.5 and 2.5 mm hex wrenches (included)
• 3 mm hex wrench (included)
• Snap-ring pliers (not included)
• Adjustable wrench (not included)
CAUTION
Before any component change or service activity, relieve air pressure from the fluid reservoirs.
Cleaning the Wetted Parts
Disassemble the Wetted Parts
1. Disconnect the actuating air, nozzle air, and fluid supply from
the valve.
2. Make a note of the current stroke setting number.
3. Loosen the stroke control knob until the spring pressure is
relieved.
4. Turn the QR clasp thumbscrew counterclockwise to disengage
the clasp.
5. Carefully move the fluid body downward until it clears the
needle-and-piston assembly.
6. Remove the double-stacked O-rings from inside the fluid
body (these O-rings typically remain in the fluid body after it is
removed).
7. Remove the fluid inlet fitting and the nozzle air fitting.
8. Remove the air cap retaining nut and then remove the air cap
and the nozzle components.
Clean the Wetted Parts
1. Clean the fluid body, nozzle, dispersion ring, air cap, and air
cap retaining nut in an appropriate solvent.
CAUTION
Do not clean the needle with an abrasive material, specifically in
chemically sensitive applications.
2. Clean the needle with a cloth dampened in solvent.
Nozzle (PEEK
nozzle shown)
Air cap
Air cap
retaining nut
Fluid inlet
fitting
QR clasp
Double-stacked
O-rings
Nozzle air
fitting
Fluid body
Removing the fluid body
Removing the nozzle
Stroke control
knob
Nozzle O-ring
Nozzle
dispersion ring
