MEGA Corp. MSC-OPS-1 - Manual (Page 23)

MSC/MST-OPS-1
31 Dec 2013
SECTION 2
System Description
2-14
TANK DRAIN
A hydraulic BFV attached to the water tank pressure
pipe is used to drain water from the water tank. The
BFV is controlled electrically from the cab control box
and is actuated by a hydraulic actuator. The actuators
receive hydraulic pressure from the solenoid control
box assembly. Tank drains can be either gravity or
pressure fed.
FIRE SUPPRESSION SYSTEM
A system that consists of a 120 or 60 gallon stainless
steel holding tank, an electric or pneumatic actuated
shut-off valve, in-cab control switch, hosing and a
foam eduction nozzle mounted to the water cannon.
FOAM CONCENTRATE TANK
A stainless steel tank
mounted in the forward
upper portion of the water
tank. The holding tank
contains a supply tube that
extends to the bottom of the
tank and connected to a
flexible hose at the top of the tank and then routed to
the foam agent shut-off valve. The tank also contains
a pressure/vacuum cap which keeps foreign matter
out of the tank while providing for pressure relief and
air displacement during temperature changes.
ELECTRIC/PNEUMATIC SHUT-OFF VALVE
The in-line shut-off valve is mounted on the foam
tank upper lip and is controlled by the in-cab control
FOAM switch. The shut-off valve is actuated by either
an electric or pneumatic actuator that is controlled
by the in-cab control switch. Once the shut-off valve
is opened, foam concentrate will flow from the
holding tank to the water cannon nozzle if the water
cannon and water pump switches are ON.
FOAM EDUCTION NOZZLE
A manual or remote
adjustable (fog/stream)
nozzle is attached to the
water cannon waterway. The
nozzle inner housing uses
high pressure water to create
a venture effect that will
create a suction force,
pulling foam concentrate from the holding tank.
Once foam concentrate is flowing, the nozzle
proportions foam concentrate, water and air to
produce finished foam. The nozzle can be adjusted to
allow control of foam solution at a rate of 1%, 3% or
6%. Rate adjustment is obtained by replacing a
removable disk.
SUCTION LOADING (IF EQUIPPED)
A second water pump mounted typically to the water
pump sump at the rear of the MAC. The suction
loading station is equipped with a manual diversion
valve that will switch the hydraulic oil flow from the
main discharge pump drive motor to the suction
loading pump drive motor. When oil is diverted to
the suction loading drive motor, it can pull water
from a holding pond and fill the MAC. The suction
loading option includes lengths of 4” suction hose
equipped with quick couplers and a check valve inlet
foot with a debris screen. The suction hoses are
typically stored in tubes either built into the MAC or a
hanging tube arrangement.