CERTIFICATION EVALUATION 2026 TESTED
QUESTIONS SOLVED
◉ Mechanical seal failure. Answer: A failure that can occur due to
overheating, excessive vibration, and low flow rates.
◉ Air blower. Answer: A device used to supply oxygen to aerobic
processes in wastewater treatment.
◉ Motor maintenance checks. Answer: Routine checks that include
lubrication of bearings, voltage and current levels, and alignment
with the drive shaft.
◉ Corrosion prevention in mechanical components. Answer:
Typically achieved using stainless steel due to its resistance to
corrosion.
◉ Pump not priming troubleshooting. Answer: Checking the pump's
discharge valve to ensure it's fully open.
◉ Cleaning a clogged pump impeller. Answer: Recommended to
remove and manually clean the impeller with a brush.
,◉ Safety precautions with electrical motors. Answer: Ensuring the
motor is properly grounded to prevent electrical shock.
◉ Mechanical strainer function. Answer: To filter out solids from
liquids in wastewater treatment.
◉ Mechanical strainers. Answer: Mechanical strainers are used to
remove large solids and debris from wastewater before it enters
treatment systems, preventing damage to equipment and ensuring
smoother operation.
◉ Oil change interval for gear reducers. Answer: Gear reducers
should be serviced according to the manufacturer's guidelines,
which often specify an interval for oil changes, typically between 6
months and 2 years depending on usage.
◉ Check valve. Answer: Check valves allow flow in one direction and
automatically close to prevent backflow, protecting pumps and other
equipment from damage.
◉ Cavitation in pumps. Answer: Cavitation occurs when vapor
bubbles form in the pump due to low pressure and then collapse,
causing noise, vibration, and potential damage to the pump.
,◉ Replacing bearings in a pump motor. Answer: It is crucial to
replace bearings with those that match the original specifications to
maintain proper motor function and extend service life.
◉ First check if a pump motor is not starting. Answer: If a pump
motor is not starting, the first step should be to check the power
supply and ensure electrical connections are intact and functioning.
◉ Variable frequency drive (VFD). Answer: A VFD allows for variable
speed operation of pumps, which helps optimize energy usage based
on system demand, reducing electricity costs.
◉ Cast iron. Answer: Cast iron is commonly used for pump impellers
due to its strength, wear resistance, and ability to withstand harsh
wastewater conditions.
◉ Sludge conveyor system. Answer: Sludge conveyors are used to
move accumulated sludge from various treatment processes to the
dewatering area or disposal site.
◉ Running a pump dry. Answer: Running a pump dry can cause
severe damage to the pump components (like the seals and
bearings), so it should be turned off as soon as possible.
, ◉ Expansion joint. Answer: Expansion joints are used to absorb the
stresses caused by thermal expansion or contraction in piping
systems, preventing pipe damage or breakage.
◉ Stainless steel. Answer: Stainless steel is commonly used for
pump shafts due to its resistance to corrosion and wear in
wastewater environments.
◉ Pressure relief valve set point. Answer: The set point for a
pressure relief valve should be adjusted based on the maximum
allowable discharge pressure to ensure safe operation and prevent
system overpressure.
◉ Screw conveyor. Answer: Screw conveyors are designed to
transport thick or wet materials, such as sludge, and are less likely to
clog over long distances.
◉ Diaphragm in a diaphragm pump. Answer: The diaphragm in a
diaphragm pump creates a barrier between the inlet and discharge
chambers, allowing the pump to move fluids by creating suction and
pressure alternately.
◉ Diffuser in wastewater treatment. Answer: Diffusers are used in
aeration tanks to evenly distribute air or oxygen throughout the
water, supporting aerobic biological processes that treat wastewater.