6
XL090
DANGER
Operating On Portable
Base Below This Stop
(pin pulled) Is Dangerous.
An automatic drain empties water from a low point in the monitor piping to prevent freezing and help empty hose lines. The valve is
designed to close automatically when pressure in the monitor exceeds approximately 5 psi and open again when the pressure drops
to that point. When the automatic drain is not desirable it may be disabled. To disable the drain valve refer to the exploded view on page
12 and follow the steps below:
1) Unscrew the drain assembly (40, 41, 42, & 43) and remove the screw and washer (42 & 43)
2) Flip over the rubber drain valve (41) so that the raised edge is against the face of the housing (40).
3) Reassemble.
4.5 ELEVATION CONTROL AND STOP PIN
When mounted on a truck base, the nozzle may be lowered below the 35° safety stop by pulling out the stop pin and rotating the
handwheel below the 35° stop. When the nozzle is raised back above 35°, the spring loaded stop pin will snap back into position
automatically limiting the elevation of the nozzle with respect to the base to 35°.
4.6 AUTOMATIC DRAIN
A sliding monitor can cause injury. When used on a portable base, keep the horizontal
angle between the water stream and the anchor strap as small as possible. At large
angles the base can slide in an arc around the anchor point.
Operating on a portable base below this safety stop is DANGEROUS. Do not operate
on portable base below safety stop. Injury or death can occur if the monitor and base
slides or lifts off the ground.
Figure 4.4.1
Unlocked
Figure 4.5.1
Elevaton control
Figure 4.4.2
Locked
Figure 4.5.2
Elevation stop pin out
Figure 4.5.3
Elevation stop pin in
DANGER
WARNING
When a nozzle is flowing water the reaction force acts in a straight line that is directly
opposite the water flowing out the end of the nozzle. If a nozzle on a monitor on a
portable base is pointed straight up, all of the reaction force is directed straight down
and there is no sideways force that can cause the base to slide. As the nozzle is
angled downward at the same flow, the reaction force remains the same, but some of
that force becomes a force acting sideways and some acts in a downward direction.
When the nozzle is at an angle of 45° the force acting sideways is equal to the force
acting downward on the base. As the elevation angle of the nozzle is lowered the
sideways force increases while the downward force decreases. At an angle of 35°,
(the angle at the elevation safety stop),
approximately 82% of the nozzle reaction force is acting sideways on the base. When the nozzle is at a zero degree angle, with respect
to the base, the entire reaction force is acting sideways on the base and there is no downward force at all. The lower the elevation angle
of the nozzle, with respect to the base, the greater the force that causes sliding, and the more likely sliding will occur.
35°
