Roto-Jet Model API R110 pages

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Engineering
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Model API-R11

The compact design of the Roto-Jet Pump
provides pulsation free pressures up to
650 PSI in only a single stage.

Operation

Design Simplicity

The Roto-Jet model API-R11 pump is totally,
hydraulically stable and can operate with a minimal
continuous bypass flow at shut-off indefinitely at any
flow point throughout the total head curve range with
no wearing or damaging effect to the pump.

A single stage pump with only two basic working
parts; (1) a rotating case and (2) a stationary pitot
or intake tube. The pump has only one wearing,
rubbing part and that is a mechanical seal that sees
only suction pressure. Seal leakage due to seal
failure vents to the atmosphere. Seal leakage cannot
contaminate the bearing area due to the isolation
of the bearing pedestal from the wetted end of the
pump. For this reason the R-11 can be kept in service
with a damaged seal to meet the critical demands of
daily production.

The reason for this unique benefit is that all radial
forces tend to be balanced within the rotor, and
axial thrust is solely a function of suction pressure.
Radial and axial forces applied to the Roto-Jet are
independent of flow rate. Thus, the pump can
operate at design point to shut-off free of shaft
deflection or added thrust load applied to the
bearings.

Seize Proof
Unlike conventional centrifugal pumps the API-R11
will not seize if run dry by a loss of suction or if
operated with a minimal continuous bypass flow
against a closed discharge valve. The mechanical
seal is not mounted to the drive shaft, therefore,
seal failure temperature rise is not transferred to the
critical drive shaft/bearing area. The design does not
incorporate wear rings or any close shaft tolerances
which would be subject to heat expansion and drive
shaft seizure.