P31 SERIES
General Instructions
1.
Page 502
REGENERATIVE TURBINE PUMPS
A. Inspection of Equipment
B. Storage
C. Placing Stored Pumps Into
Service
D. Application Considerations
E. Recommended Spare Parts
When properly installed and given
reasonable care and maintenance,
regenerative turbine pumps should
operate satisfactorily for many years.
Because of the high differential pres-
sures expected in a regenerative
turbine pump, close running clear-
ances are used to reduce internal
losses. Abrasive particles, even
microscopic ones in high enough
concentrations can open up the close
clearances between internal cavities.
For critical services it is recommend-
ed that you keep an identical pump
for stand-by use.
1A Inspection of Equipment
Immediately upon receipt of the
shipment, inspect the equipment for
damage or missing components.
Check the shipping manifest and
report any damage or shortage to
the Transportation Company’s local
agent. Inspect the crate and any
wrapping material before discarding.
Parts or accessories are sometimes
wrapped individually or fastened to
the skid.
Put the instructions that came with
the shipment in a safe place where
they will be available to those who
will be using them for installation and
service.
1B Storage
If the pump is to be stored before
use, it should be inspected as de-
scribed in 1A, recrated and stored
in a dry location. Standard shipping
containers are not suitable for out-
door storage. In some areas, it may
be necessary to cover the pump’s
exterior surface with oil or other rust
inhibiting coating. All units are tested
at the factory with a water/corrosion
inhibitor solution, some of which will
remain inside the pump upon receipt.
If units are flushed out prior to stor
-
age, this inhibitor will be removed
and proper care must be taken to
prevent product deterioration from
improper storage.
For storage beyond 30 days, a corro-
sion inhibiting protective fluid should
be added to the internal pump cavi-
ties. Fluids used in the pump should
be selected for compatibility with
pump materials. This is very impor-
tant when optional seal and gasket
materials have been used. Protective
caps on the inlet and outlets should
also be used. Caps alone are not suf-
ficient protection.
1C Placing Stored Pumps into Service
Special care must be taken when
placing stored pumps into service.
First clean the outside and flush out
the inside with a process compatible
fluid. Try to turn the pump using the
coupling or shaft. On close coupled
units, access to the shaft is between
the pump and motor. A vise grip or
other plier type gripping device may
be used directly on the shaft. Apply-
ing torque to the motor fan blades
is not recommended. If the impeller
does not break loose immediately, fill
the pump with a process compatible
fluid and try again in a few hours.
If this fails, loosen only the pump
cover thru bolts clamping the assem-
bly together, one full turn, no more.
Fill the pump with fluid. Apply torque,
50 foot pounds maximum, to the
shaft. The pump should turn before
50 foot pounds is reached. If you
are successful at breaking loose the
unit, continue turning the pump while
retightening the thru bolts to their
original positions.
If the unit still won’t turn over, DO
NOT apply further force. Refer to the
Disassembly/Reassembly Instruc-
tions in Section 5 to determine the
cause of the problem.
1D Application Considerations
1D1 Electrical Wiring
All electrical equipment and wiring
should conform to Local and National
Electrical Codes. Use the motor
manufacturer’s instructions for con-
necting the motor. Note the correct
rotation and wiring diagrams on the
assembly. Make sure the motor rota-
tion and speed matches that required
for the pump.
1D2 Construction Materials
While it is reasonable to assume
that good judgement has been used
in selecting all the materials in the
pump for compatibility with process
fluids, actual conditions sometimes
vary from original expectations. Also,
typical material selection charts do
not consider all the temperature,
pressure, and fluid variables. The
customer’s engineer should be con-
sulted for final judgement on the best
materials for critical process applica-
tions.
1D3 Valves
The first valve to be considered for a
regenerative turbine pumping system
is often a pressure relief valve.
Because this type of pump has a
horsepower requirement similar to
that of a positive displacement pump
(constantly rising along with a pres-
sure increase) a relief valve can be
effectively used to limit horsepower.
This is helpful when a non-overload-
ing motor is specified. It can be
of critical importance if the system
flow rate can vary widely. There are
almost no circumstances where a
flow modulating valve will work suc
-
cessfully in a regenerative turbine
pumping system. The steep pump-
ing characteristic, typical of these
pumps, produces very large pressure
changes with small variations in flow
rate. As a result, the modulating flow
from these valves introduce sharp
pressure shock waves that shorten
pump life and may cause damage
in other pieces of equipment in the
system.
If a shutoff valve is necessary in the
suction line, use a gate, ball, but-
terfly, or other full port valve. Globe
or other flow restricting valves can
in some cases reduce pump flow or
increase chances of cavitation.
A swing check valve is recommended
in the suction line even when the
pump inlet is only slightly higher than
the fluid source. It should be the
