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3.2 System design and installation 3. Installation
Step 1
When designing the pumping system:
- Confirm the Net Positive Suction Head requirements of the
pump (NPSHr) are met by the system, as this is crucial for
ensuring the smooth operation of the pump and
preventing cavitation.
- Avoid suction lifts and manifold/common suction lines for
two pumps running in parallel, as this may cause vibration
or cavitation.
- Protect the pump against blockage from hard solid
objects e.g. nuts, bolts etc. Also protect the pump from
accidental operation against a closed valve by using one of
the following methods: - relief valves, pressure switch, and
current limiting device.
Discharge line
Plan view
Suction line
Step 2
Before the pump is installed it is advisable to consider the following:
Always
- ensure that the mounting surface is flat to avoid distortion of the baseplate, as this will cause pump/motor shaft misalignment
and pump / motor unit damage.
Check
- pump shaft to motor shaft alignment is within manufacturers limits once the base plate has been secured.
Always allow at least 1 m for pump access / maintenance all around the pump.
- Fit suction and discharge pressure monitor points for diagnostic purposes.
- Fit valves if two pumps are to be used on manifold/common discharge lines.
- Make the necessary piping arrangements if flushing is required for the seal or if media is required for heating/cooling jackets.
- Do not subject the pump to rapid temperature changes. Pump seizure can result from thermal shock.
Step 3
All pipework must be supported. The pump must not be allowed to support any of the pipework weight beyond the limits set in
the following table.
Remember:
Pipework supports must also support the weight of the product being pumped.
Always:
- Design short straight suction lines to reduce friction losses in the pipework thereby improving the NPSH available from the
system.
- Avoid bends, tees and any restrictions close to either suction or discharge side of pump. Use long radius bends wherever
possible.
- Provide isolating valves on each side of the pump to isolate the pump when necessary.
- Keep pipework horizontal where applicable to reduce air locks. Include eccentric reducers onsuction lines.
Plane ‘X’
Plane ‘Z’
Plane ‘Y’
