WTO Equipment Maintenance & Troubleshooting 2

Question 1

A centrifugal pump is experiencing cavitation. Which symptom is most characteristic of this condition?

Accepted Answer

Rattling or crackling noise with fluctuating flow

Answer

Cavitation causes vapor bubbles to collapse violently, producing a rattling or crackling noise accompanied by erratic flow and reduced pump efficiency.

Question 2

When performing a routine inspection of a chemical metering pump, the operator notices the diaphragm is cracked. What is the appropriate immediate action?

Accepted Answer

Replace the diaphragm before resuming chemical feed

Answer

A cracked diaphragm will leak chemical and deliver inaccurate doses, so it must be replaced immediately before the pump is returned to service.

Question 3

Which type of valve is best suited for throttling flow in a water treatment plant pipeline?

Accepted Answer

Globe valve

Answer

Globe valves are designed for throttling because their disc and seat arrangement allows precise flow control with minimal turbulence.

Question 4

A turbidity meter at the filter effluent is reading consistently higher than expected. Which maintenance step should be performed first?

Accepted Answer

Clean and calibrate the turbidimeter using standards

Answer

Before making operational changes, the turbidimeter should be cleaned and verified with calibration standards to confirm the reading is accurate.

Question 5

What does a high amperage reading on a pump motor most likely indicate?

Accepted Answer

The impeller is oversized or there is mechanical binding

Answer

High amperage indicates the motor is working harder than normal, which can result from an oversized impeller, mechanical binding, or excessive back pressure.

(WTO) Water Treatment Operator Certification Practice Test

(WTO) Water Treatment Operator Certification Practice Test

WTO Equipment Maintenance & Troubleshooting 2