Spray Pattern Adjustment
14
311320K
Spray Pattern Adjustment
1. Check valving rod clearance in closed position. Rod
should extend approximately 1/32 in. (1 mm)
beyond tip of mixing chamber. If it does not, see
Valving Rod Adjustment
procedure, page 20.
2. Adjust valving rod travel to initial setting.
a. Loosen friction lock. Turn valving rod
adjustment screw clockwise until it stops.
b. Turn valving rod adjustment screw 11 times
counterclockwise.
3. Locate point of valving:
a. Aim gun at disposable target.
b. Dispense short (1 second) bursts toward target
while simultaneously withdrawing valving rod
adjustment screw from retainer case by 1/4-turn
increments in counterclockwise direction.
c. Point of valving is reached when chemical
stream mists as shown in F
4. Adjust spray pattern. Note position of notch in
hexhead of adjustment screw, then back screw out
counterclockwise the number of turns specified in
Table 1. Notice spray pattern opens as adjustment
is made (F
This adjustment may create a large mass “bun” of
urethane foam. Very high temperatures created by
chemical reaction inside a bun may not dissipate after
outside surface has cooled. A large bun may continue
to react for several hours after spraying until flash
(burning) point of foam is reached.
Always
break
buns into smaller pieces so heat can escape.
F
IG
. 10 Valving Rod (Closed Position)
1/32 in.
F
IG
. 11 Point of Valving
F
IG
. 12 Opening Spray Pattern
