4.3 System design, installation and operation
When designing, installing and operating pipework systems where pumps are used, especially where
the pumped media is viscous, there are general recommendations and good engineering practices
that should be employed to ensure long term, reliable pump and system operation.
Design
- Confirm the Net Positive Suction Head (NPSH) available from the system exceeds the NPSH
required by the pump, 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 and/or cavitation.
- Protect the pump against blockage from hard solid objects e.g. nuts, bolts welding slag etc. Also
protect the pump from accidental operation against a closed valve by using relief valves, pressure
switches or current limiting devices.
- Fit suction and discharge pressure monitor points for diagnostic purposes.
- Fit valves, it two pumps are to be used on manifold/common discharge lines.
- Make the necessary piping arrangements if flushing is required for the seal.
- Allow at least 1 m for pump access/maintenance all around the pump.
To reduced the risk of damaged caused by sudden changes in temperature (thermal shock) ensure
any temperature changes are done gradually and equipment temperature is allowed to stabilise
before operation.
Pipework:
All pipework must be supported. The pump must not be allowed to support any of the pipework weight
beyond the limits set as shown in the following table.
Remember:
- Pipework supports must also support the weight of the product being pumped.
- 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 when necessary.
- Keep pipework horizontal where applicable to reduce air locks. Include eccentric reducers on
suctions lines.
200002348-1-EN-GB
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Installation 4
EN
Summary of Contents for DuraCirc Range
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