discharge pressure are related to the pump speed.
Decreasing the engine speed, and
thus the pump speed, will decrease the water discharge volume and pressure. If
operating at less than maximum volume and pressure, increasing the engine speed
will increase the pump output.
The pumping assembly has controls that sense the
suction and discharge pressures.
When operated in an automatic mode, the controls
adjust the engine speed as needed to regulate the pump output.
1.14.1 Source or Lead Pump.
When operated as a source or lead pump, the pumping
assembly draws water from a large source,
such as a lake or stream or a storage
facility that is supplied by wells, water purification units, or desalination
operations.
If operated singly as a source pump, the water is fed to another
storage facility.
If operated as a lead pump, the water is fed downline through a
hoseline or pipeline to a boost pump.
1.14.2 Boost Pump.
When operated as a boost pump, the pumping assembly draws water
from a hoseline or pipeline and feeds it downline to the next boost pump or to a
storage facility.
Operated manually during startup and can then be switched to an
automatic mode for sustained operation.
In automatic mode, engine speed is
regulated automatically.
1.14.3 Engine and Control Electrical System.
The engine starter and engine controls are
supplied with direct current (de) electric power by the pumping assembly battery or
batteries and engine alternator.
1.14.4 Trailer Lights.
The trailer lights are supplied with 24 volts dc through an
electrical cable connected to the towing vehicle.
1.14.5 Trailer Hydraulic Brake System.
The pumping assembly trailer is equipped with an
inertial hydraulic brake system.
The inertial hydraulic brake system automatically
applies the brakes when the vehicle SlOWS or stops or when the trailer accidentally
uncouples from the towing vehicle.
The brake system includes a drawbar ring or
lunette, a hydraulic brake actuator, a master cylinder, a breakaway lever and
chain, brake lines, wheel cylinders, brake shoes, and brake drums.
1.14.5.1 Lunette.
The lunette attaches to the towing vehicle.
It is connected to the
hydraulic brake actuator, which controls the master cylinder.
When the towing
vehicle moves forward the lunette is pulled and the brakes are released.
When the
towing vehicle slows down, the trailer pushes the lunette against the towing
vehicle, which causes the brakes to be applied.
1.14.5.2 Hydraulic Brake Actuator.
The hydraulic brake actuator connects the drawbar
ring/lunette to the master cylinder.
It transmits mechanical motion from the
drawbar ring/lunette to the master cylinder.
1.14.5.3 Master Cylinder.
The master cylinder receives mechanical motion
hydraulic brake actuator and from the breakaway lever.
It changes the
motion into hydraulic pressure.
The hydraulic pressure is transmitted
brake lines.
1.14.5.4 Breakaway Lever and Chain.
The breakaway chain is attached to the
from the
mechanical
through the
breakaway
lever and to the towing vehicle.
It will pull the breakaway lever up if the
trailer accidentally uncouples from the towing vehicle.
When the breakaway lever
is pulled up, it transmits mechanical motion to the master cylinder and applies
brakes.
1.14.5.5 Brake Lines and Wheel Cylinders.
The brake lines transmit hydraulic pressure
from the master cylinder to the wheel cylinders.
When pressurized, the wheel
cylinders engage the brake shoes.
1.14.5.6 Brake Shoes and Drums.
When wheel cylinder pressure causes the brake shoes to
be engaged, the brake shoes press against the brake drums.
This causes friction
that slows and stops the trailer.
The brake shoes disengage from contact with the
brake drums when the pressure is released.
1-15/(1-16 Blank)
TM 10-4320-344-10
