Hale 2CBP - Manual (Page 12)

Sec I- 8 Introduction
Booster Pumps
EXPLANATION OF TERMS
Atmospheric Pressure
Static air pressure. Air pressure is 14 pounds
per square inch at sea level. Pressure increases
below sea level and decreases above sea level.
The weather also effects air pressure. Air in a
high pressure area compresses and warms as it
descends. The warming inhibits the formation of
clouds, meaning the sky is normally sunny in
high-pressure areas. But haze and fog still
might form. Just the opposite occurs within an
area of low atmospheric pressure. Atmospheric
pressure effects a pumps ability to pump from
draft. Higher pressures will increase a pumps
performance, while lower pressures can cause
a noticeable decrease in lift.
Cavitation
The sudden formation and collapse of low-
pressure bubbles in liquids by means of
mechanical forces, such as those resulting from
rotation of a pump impeller.
Dead Heading
Operating a pump without any discharge. Lack
of flow causes temperatures to rise inside the
pump.
Impeller
The working part of centrifugal pumps which
imparts energy (motion) to the water.
Essentially, an impeller consists of two discs
separated by curved vanes. The vanes force
the water to rotate between the discs and is
thrown outward at high velocity. The water from
the impeller discharges into a diverging
passage known as a volute, converting the high
velocity energy of the water into pressure.
Priming Pump
An auxiliary positive displacement pump which
pumps air out of the booster pump creating a
vacuum in order to prime the pump. The
priming pump is a rotary vane type, electric
motor driven. Once the main pump is primed
and pumping, the priming pump is shut off.
Relief Valve
An automatic valve which, when activated by
the relief valve control will hold the pump
pressure to no more than 30 PSI when the
pump discharge is gated or closed. The valve
maintains a set pressure by diverting the pump
discharge flow into the pump suction.
Relief Valve Control (PM)
A hand adjustment valve. When set to the
desired pressure, the relief valve will maintain
the desired pump discharge pressure and limit
a pressure increase to no more than 30 PSI (2
BAR).
Volute
The increasing discharge path of the pump, its
function is to collect the water from the impeller
and depending on its design can either increase
pressure and decrease velocity or increase
velocity and decrease pressure.