Hale 2CBP - Manual (Page 8)

Sec I- 4 Introduction
Booster Pumps
confined to increase acceleration and pressure.
The discharging tube is widest at the pump
outlet. The increasing discharge path, known
as the volute, collects the fast moving water and
converts the water's velocity into pressure.
Mechanical Seal
The mechanical seal is common to all Hale
booster pumps. Shown in figure 1-6, a
stationary seat is in constant contact with a
rotating seal ring to prevent leakage. The
sealing diaphragm is made of a rubber
elastomer specifically designed for high-
temperature operations.
If a pump is operated without water for
extended periods, or without discharging water,
it may overheat. This may damage the
mechanical seal or the drive mechanism.
Gearbox
The gearbox is typically constructed of fine
grain alloy cast iron. Inside the gearbox (Figure
1-5) a gear set and input drive shaft made of
heat-treated nickel steel, transfers engine power
to the impeller. Hale offers a variety of pump
gear ratios to accommodate a wide range of
end-user and apparatus manufacturer
requirements based on the pump's intended
use, horsepower and speed rating of the
engine, and the torque rating of the
transmission PTO.
Pump Drives
There are four common types of booster pump
drives used on fire fighting apparatus:
1. The most common drive is the PTO mounted
on the truck transmission or four-wheel drive
transfer case which allows for pump and roll
operation.
2. A stand-alone drive with separate engine
(auxiliary engine).
3. The truck chassis engine crankshaft (front-
engine PTO).
4. Hydraulic Motor
Hale booster pumps are built to produce the
volumes and pressures shown on their
respective performance curves. However, the
volumes and pressures safely obtainable are
dependent on the torque capacity of the
apparatus transmission or transfer case, power
takeoff and the pump drive line. In most cases,
the torque rating of the PTO determines
maximum pump performance.
The apparatus builder can give various pump
performance spots that will define the torque
limit of the PTO in terms of GPM and PSI.
When pumping continuously, care should be
taken not to overheat the apparatus' PTO,
transmission or transfer case.
HALE Power Takeoff Pumps
Hale booster pumps are available for either
engine rotation or opposite engine rotation PTO
operation. Additionally, the pump can be
configured to discharge in a variety of positions.
Since some PTOs match engine rotation and
some turn opposite of the engine rotation, each
pump model can be built to match the rotation
of the PTO.
Figure 1-6: Mechanical Seal