INSTALLATION & SERVICE INFORMATION
FLOJET R3B21 Series pumps are designed for a wide range of
applications and are constructed from a selection of materials
suitable for handling a broad range of chemicals. The three
chamber high flow pumps are self-priming and can run dry
without harm. They are intended for intermittent duty cycles but
can be run continuously for short periods of time. The higher the
duty cycle, the shorter the expected life of the pump. Typical uses
include transfer, delivery, spraying, cooling, filtration, dispensing,
and pressure boosting.
OPERATION
To start and prime the pump, the discharge line must be
opened to allow trapped air to escape, thus avoiding the
potential of airlock. For demand models, the pressure
switch will shut off the pump automatically when the
discharge valve is closed and the pressure has risen to
the switch OFF set point. The pressure switch will restart
the pump when a valve is opened and the discharge line
pressure drops to the ON set point of the pressure switch.
For bypass models, apply power to the pump, and open
the discharge valve to expell air in the line.
DEMAND OPERATION (intermittent duty)
Pump models fitted with a pressure switch are known as
demand pumps. The pressure switch is preset to shut off
the pump motor automatically when a specific pressure
is reached, such as in closed discharge conditions. The
pressure switch turns the pump motor on automatically
as the pressure drops, such as when the discharge is
opened. Demand operation is considered an “intermittent
duty” application. The maximum intermittent duty cycle
is that which will cause the motor to reach its maximum
thermal limits. Once the maximum thermal limit is
reached, the motor must be allowed to settle to a lower
(ideally ambient) temperature, before resuming operation.
Running the pump at or near the maximum thermal limit
for an extended period of time will shorten the life of the
pump and may result in immediate pump failure. Demand
pump models feature an integral pressure switch that
automatically turns the pump off/on in response to open/
closed discharge conditions.
BYPASS OPERATION (if equipped)
Models equipped with an external bypass system are
designed to pump at high pressures while at low or
high flow rates. Models equiped with bypass only must
be turned off/on manually, or by an independent control
device. Models equipped with a bypass only will continue
to run until the power is manually turned off.
The R3521/03521 Series pumps are not recommended for
continuous duty service due to limited motor brush life.
Operation at lower pressures and temperatures, however,
will extend overall pump service life.
MOUNTING
The R3B21 Series pumps are self-priming and may be
located above or below the water supply in a dry location.
To vertically mount these units, it is best to do so with
the motor on top. This will prevent water dripping on the
motor in the event of a leak. Place pump on a solid surface
and secure with the four mounting screws; be careful not
to compress the rubber grommets, which act as vibration
dampers.
