3
Use a straight edge and
gauge to check the parallel
alignment and the angular
alignment.
Adjustment is usually made
by moving the motor, and
adding or subtracting shims
from under the motor feet.
(See Figures 5a and 5b.)
A10: Pipe Connections
Pipes must be independently supported, and arranged in such a
way that expansion or contraction along the length of the pipe does
not impose strain on the pump flanges. Never use the pump itself
to support the pipes. Locate pipe supports close to the pump.
Never force the pipes into place to align with the pump flanges, as
this will impose unacceptable loads on the pump. Where neces-
sary, flexible jointed pipework should be fitted to accommodate
small movement of the pipe and eliminate strain on the pump.
It is usual practice to fit pipes of one or two sizes larger than the
bore of the pump’s suction and discharge. For short pipe runs, it
may be economical to fit pipes of the same diameter as the pump
flanges. Do not fit pipes of a smaller bore than the pump flange size.
Most systems require the installation of suction and discharge
valves, and a non-return valve on the discharge pipeline. We would
recommend fitting such valves for ease of maintenance. If the
flowrate is to be regulated or initially set with the discharge valve,
fit a gate valve in preference to a wafer type discharge valve.
Before final connection of the pump on a new system, thoroughly
clean and flush all suction pipes and tanks to eliminate weld
debris and scale, which can become dislodged and block the
suction of the pump. A temporary strainer can be fitted to the
suction line to prevent debris from entering the pump.
A11: Electrical Connection
Where the pump is to be driven by an electric motor, observe the
instructions provided by the electric motor manufacturer.
Electrical installation should only be carried out by a skilled elec-
trician. The installation should be grounded at the motor, pipes,
support frame and pump as appropriate.
A12: Vibration Isolation
Pumps installed in some buildings may require isolation from the
floor and pipes using anti-vibration mounts and flexible pipe con-
nectors.
B:
OPERATION
When correctly installed and operated, this Taco pump will give
many years of trouble-free service. In operation, the pump should
be free from vibration and run smoothly. Any changes to smooth-
ness of operation should be investigated immediately. The pump
should be visually checked periodically.
B1: Priming the Pump
Pumps operating on flooded suction conditions (where the liquid
source is higher than the pump) are easily primed by opening the
suction valve, releasing air vent on the pump discharge, and
allowing the pump casing to fill with liquid. (See Figure 6.)
For pumps operating on a suction lift, the usual practice is to fit a
foot valve to the suction pipe. This foot valve retains liquid within
the suction pipe and pump casing when the pump is idle.
B2: Starting the Pump
Before the pump is started for the first time, it is important to
check the following points:
• Check that the pump rotates freely by hand.
• Open the suction valve fully and evacuate all the air
inside the pump casing to prime the pump.
• Close the discharge fully for the first start after
installation or service.
• Momentarily start and stop the electric motor or engine
driver to check that the rotation is correct.
• The pump may now be run. On starting, observe the
discharge pressure.
• Slowly open the discharge valve. The pressure will
gradually fall as the flowrate through the pump increases.
• Open the discharge valve only until the required pressure
is indicated on the pressure gauge.
B3: Over-Pumping
When pipework system losses are estimated, an extra allowance
in head is often made for pipe deterioration, or the pump is over-
sized to allow for future expansion. In these circumstances, it is
likely that the pump will operate at a higher flowrate than intended,
which may result in excessive loads on the pump bearings and
driver overload. The operator should limit the flow by adjustment
of the discharge valve, referring to the discharge pressure gauge
to obtain the design conditions. For pumps driven by electric
motor, the operator should verify that the motor nameplate current
is not being exceeded.
B4: Minimum Flowrate
Taco GT pumps should not be continually operated at a flowrate
below 30% of the peak efficiency flowrate unless otherwise
specifically agreed by the manufacturer. If the system is such that
zero flow or less than 30% of peak efficiency flow will occur, a
return line must be fitted.
CAUTION: Isolate the electrical supply
before commencing work on the pump.
Figure 5b
AIR VENT
Figure 6: Air Vent Location