V1.4
21 of 22 04/01/2009
• Install the housing over the rotor head positioned on the bracket register.
• Place the idler gear on the pin in the cover assembly and position in the housing
register.
• Align the matching marks for proper location.
• Install the cover screws. Tighten gradually, alternating from a screw on one side to a
screw on the opposite side.
• Install the packing or seal, following the instructions for the specific model in question.
• Check the end clearance.
Troubleshooting
No fluid is delivered.
•
Power is not on.
•
Net positive suction head available (NPSHA) is lower than required for the inlet
conditions and the vapor pressure of the liquid pumped. Calculate NPSHA and
redesign piping if necessary.
•
Leaks in suction line or port passages. These can be detected by submerging the
pressure line from the discharge side of the pump into a pail of liquid where the air
will be seen in the form of bubbles.
•
Direction of shaft rotation is incorrect.
•
Pump shaft is not rotating. The coupling is defective or the tongue and groove are
not engaged.
•
The relief valve setting is too low. Liquid is discharging through the by-pass port.
Capacity is too low.
•
There are leaks in the suction line.
•
Suction losses are too high. The suction lift is too great or the suction line too
small or too long. This can be detected by installing a vacuum gauge directly at
the pump suction. The maximum vacuum at the pump suction should never
exceed 15" of mercury. Vaporization caused by higher vacuums will generally
result in capacity drop-off. Suction conditions must be redesigned.
•
Pump speed is too slow.
•
The strainer is too small or obstructed.
•
The suction port or pipe is not immersed deeply enough in the liquid.
•
Piping is improperly installed, permitting an air pocket to form in the pump.
•
Increased clearances or wear in the pump will sometimes cause the pump to
deliver an insufficient supply of fluid. This can generally be corrected by
reducing the thickness of the cover gaskets. A folded gasket or a slight amount
of dirt can exaggerate the problem and cause leakage.
Pump works spasmodically.
•
Leaky suction line.
•
Varying suction conditions.
•
Air or vapor in the fluid.
