CAUTION:
Observe pump for vibration levels, bearing temperature and excessive noise. If normal levels
are exceeded, shut down and resolve.
4.4 Operation
4.4.1 General considerations
Always vary capacity with regulating valve in the dis charge line. Never throttle flow from the suction
side.
Driver may overload if the pumpage specific gravity (density) is greater than originally assumed, or the
rated flow rate is exceeded.
Always operate the pump at or near the rated conditions to prevent damage resulting from cavitation or
recirculation.
4.4.2 Operating at reduced capacity
WARNING:
Do not operate pump below minimum rated flows or with suction and/or discharge valve
closed. These conditions may create an explosive hazard due to vaporization of pumpage and
can quickly lead to pump failure and physical injury.
Damage occurs from:
1.
Increased vibration levels - Affects bearings, stuffing box or seal chamber, and mechanical seal.
2.
Increased radial loads - Stresses on shaft and bearings.
3.
Heat build up - Vaporization causing rotating parts to score or seize.
4.
Cavitation - Damage to internal surfaces of pump.
4.4.3 Operating under freezing conditions
Exposure to freezing conditions, while pump is idle, could cause liquid to freeze and damage the pump.
Liquid inside pump should be drained. Liquid inside cooling coils, if supplied, should also be drained.
4.5 Shutdown
1.
Slowly close discharge valve.
2.
Shut down and lock driver to prevent accidental rotation.
WARNING:
When handling hazardous and/or toxic fluids, proper personal protective equipment should be
worn. If pump is being drained, precautions must be taken to prevent physical injury. Pumpage
must be handled and disposed of in conformance with applicable environmental regulations.
4.4 Operation
32
3196CC Installation, Operation and Maintenance Instructions