Hitachi 308640 How the Air-Assisted Spray Gun Operates, Install a Spray Tip, Your application

Operation

How the Air-Assisted Spray Gun Operates

The air-assisted spray gun combines airless and air spraying concepts. The spray tip shapes the fluid into a fan pattern, as does a conventional airless spray tip. Air from the air cap further atomizes the fluid and completes the atomization of the paint tails into the pattern to produce a more uniform pattern. The width of the pattern can be slightly adjusted by the pattern adjustment valve.

Note that the air-assisted spray gun differs from an air spray gun in that increasing the pattern air reduces the pattern width. To increase the pattern width, less pattern air or a larger size tip must be used.

The spray gun has a built-in lead and lag operation. When triggered, the gun begins emitting air before the fluid is discharged. When the trigger is released, the fluid stops before the air flow stops. This helps assure the spray is atomized and prevents fluid buildup on the air cap.

Install a Spray Tip

WARNING

INJECTION HAZARD

To reduce the risk of a fluid injection injury, follow the Pressure Relief Proce- dure on page 7 before removing or

installing a spray tip.

Install a spray tip in the gun. The air cap and spray tip position determines the direction of the spray pattern.

Rotate the air cap (the spray tip rotates with it) as needed for the desired spray pattern direction. See Fig. 3.

NOTE: If the gun has the AA RAC assembly, hand- tighten the air cap retaining ring, while holding the orange tip guard in the desired direction. If the retain- ing ring is over-tightened, the spray tip will be difficult to rotate.

Vertical Spray Pattern Horizontal Spray Pattern

Select a Spray Tip and Air Cap
The fluid output and pattern width depend on the size
of the spray tip, the fluid viscosity, and the fluid pres-
sure. Use the Spray Tip Selection Chart, on page 22,
as a guide for selecting an appropriate spray tip for	05991
your application.	Fig. 3

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