Hale MG - Manual (Page 21)

Muscle Pumps
1-14
J-Series Gearbox
The Hale J-Series Gearbox, available for the Qpak
pump, is a heavy duty gearbox that is driven from
a transmission-mounted PTO allowing for pump
and roll applications. This gearbox has a wide
range of ratios available to allow for use on
different engine and transmission combinations.
E. Accessories
Priming Pump
Priming pumps are used to create a vacuum: they
are designed to evacuate air in the suction hose
and the pump. The vacuum created allows
atmospheric pressure to push water from the open
source through the suction hose and into the
pump. Hale centrifugal midship pumps use
Rotary Vane Positive Displacement pumps for
priming. A positive displacement pump moves a
specified amount of air or fluid with each
revolution. As shown in figure 1-14, the priming
pump has a single rotor mounted off-center
(eccentric) to the pump body housing.The vanes
in the rotor slide in groves and are held against
the body housing by centrifugal force. As a vane
turns toward the discharge, it recedes into the rotor.
As the rotor continues past the discharge, the vane
advances outward from its groove and against the
body housing. During this cycle, the space between
the rotor and housing cases fills with air, and the
vanes, acting as wipers, force air out of the
discharge, creating a vacuum in the main pump
allowing atmospheric pressure to push water into
the hose and into the suction side of the main
pump.
A Hale priming pump has a single control that both
opens the priming valve between the midship
pump and the priming pump and starts the priming
motor.