Hex head bolt
Cooling fan cover
Water pump
If the pump turns but no water flow (make sure the flow control valve before the flow meter is open), there is a
chance that air bubble is trapped in the pump.
In the case of Heat Exchanger unit:
Connect the drain valve next to the pump discharge to outside water supply, open the drain valve and close
the flow control valve before the rotameter. The water supply will purge out air bubbles.
Close the drain valve and remove the outside water connection.
Turn on the pump again to ensure water is circulating.
In the case of HB030M Series and Parallel Pump, multi speed:
Connect the pump discharge hose to the Hydraulics Bench discharge.
Remove the check valve on the pump suction hose.
Open all valves and turn on the Hydraulics Bench pump to purge out air bubbles from the multi speed pump.
After 1-2 minute, turn off the Hydraulics Bench pump and immediately put back the check valve on the
suction hose.
Remove the discharge hose from the Hydraulics Bench and turn on the multi speed pump to ensure normal
flow.
Figure 4
Drain Valve
4.2 Pump without Coupling
If the pump does not turn when it is turned on, the shaft may be seized. Turn off the pump and use a wrench to
turn the extended hex head bolt at the back of the motor to loosen the shaft as per below.
Figure 5
Hex-head bolt
In the case that the hex head bolt as the above is not provided, the pump shaft may be turned by removing the a
drain plug at the bottom of the pump or a plug at the top of the pump, and use a screw driver to turn the
impeller (hence the shaft).
Drain valve
