Page 588 - Subyek Teknik Mesin - Forsthoffers Best Practice Handbook for Rotating Machinery by William E Forsthoffer

The Post-Shipment Phase: Installation, Pre-Commissioning, Commissioning and Start-up Best Practices Be st Practice 1 0.12

Fig 10.12.14 -

Typical Refinery Mini Information Session -
Steam Turbines

Presented by Bill Forsthoffer
October 11,1998

Fig 10.12.11 - Fig 10.12.15 -

What is the root cause of Cavitation?
What can cause----------?

Hint --it happens at low flow rates
Look at Fig. This is a picture taken in a plastic pump with a
strobe (disco) while the pump is operating at low flow.
What do you see? That’s right--recirculation. It’s a type
of cavitation and can be very bad!

Fig 10.12.12 What is Recirculation?

If a pump operates in the heart of the curve, no problem.
If a pump does not operate in the heart of the curve, the
seal, bearing, shaft, impeller or case can be damaged and
vibration increases. Keep your eye on flow (if you have a
flow meter) or what else tells you flow changed?
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Fig 10.12.13 In Conculsion Fig 10.12.16 -

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