Spray Pattern Adjustment
Spray Pattern Adjustment
This adjustment may create a large mass “bun” of urethane foam. Very high tempera- tures 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.
1.Check valving rod clearance in closed posi- tion. Rod should extend approximately 1/32 in. (1 mm) beyond tip of mixing chamber. If it does not, see Valving Rod Adjustment procedure, page 21.
1/32 in. 
FIG. 10: Valving Rod (Closed Position)
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 with- drawing valving rod adjustment screw
from retainer case by
c.Point of valving is reached when chemi- cal stream mists as shown in FIG. 11.
FIG. 11: Point of Valving
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 pat-
14 | 311320H |
