The Pumping Principle
Tuthill C Series cast iron pumps employ
the internal gear pumping principle. There are
only two moving parts. Pumping action is
based on a rotor, idler gear, and crescent-
shaped partition cast integral with the cover.
Power applied to the rotor is transmitted to
the idler gear with which it meshes. The space
between the outside diameter of the idler and
the inside diameter of the rotor is sealed by
the crescent.
As the pump starts, the teeth come out of
mesh, increasing the volume. This creates a
partial vacuum, drawing the liquid into the
pump through the suction port.
The liquid fills the spaces between the
teeth of the idler and the rotor and is carried
past the crescent partition through the
pressure side of the pump.
When the teeth mesh on the pressure side,
the liquid is forced from the spaces and out
through the discharge port.
WARNING
WARNING
Failure to follow these instructions could result in serious bodily injury or death.
These pumps should not be used for handling plain water, corrosive or abrasive liquids or
liquids not possessing adequate lubricity.
Do not attempt to work on any Tuthill pump installation before completing the steps below.
Disconnect the drive so that it cannot be started while work is being performed.
Review the Material Safety Data Sheet (MSDS) applicable to the liquid being pumped to
determine its characteristics and the precautions necessary to ensure safe handling.
Vent all pressure within the pump through the suction or discharge lines.
All Tuthill pumps contain residual 200 SSU lube oil from the factory production test.
Determine if this is compatible with the fluid you are pumping. If the fluid is incompatible, consult
the factory.
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