CWEA Mechanical Technologist Grade 1 - Certification Exam Questions & Verified Answers
Centrifugal pump A device that moves liquids by transferring kinetic
energy.
Mechanical seal failure A failure that can occur due to overheating, excessive
vibration, and low flow rates.
Air blower A device used to supply oxygen to aerobic processes in
wastewater treatment.
Motor maintenance checks Routine checks that include lubrication of bearings,
voltage and current levels, and alignment with the drive
shaft.
Corrosion prevention in mechanical Typically achieved using stainless steel due to its
components resistance to corrosion.
Pump not priming troubleshooting Checking the pump's discharge valve to ensure it's fully
open.
Cleaning a clogged pump impeller Recommended to remove and manually clean the
impeller with a brush.
Safety precautions with electrical Ensuring the motor is properly grounded to prevent
motors electrical shock.
Mechanical strainer function To filter out solids from liquids in wastewater treatment.
Mechanical strainers 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.
Stuvia 2026-2027 | Latest Version
,CWEA Mechanical Technologist Grade 1 - Certification Exam Questions & Verified Answers
Oil change interval for gear reducers 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 Check valves allow flow in one direction and
automatically close to prevent backflow, protecting
pumps and other equipment from damage.
Cavitation in pumps 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 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 If a pump motor is not starting, the first step should be
starting to check the power supply and ensure electrical
connections are intact and functioning.
Variable frequency drive (VFD) A VFD allows for variable speed operation of pumps,
which helps optimize energy usage based on system
demand, reducing electricity costs.
Cast iron Cast iron is commonly used for pump impellers due to
its strength, wear resistance, and ability to withstand
harsh wastewater conditions.
Sludge conveyor system Sludge conveyors are used to move accumulated
sludge from various treatment processes to the
dewatering area or disposal site.
Running a pump dry 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 Expansion joints are used to absorb the stresses
caused by thermal expansion or contraction in piping
systems, preventing pipe damage or breakage.
Stuvia 2026-2027 | Latest Version
, CWEA Mechanical Technologist Grade 1 - Certification Exam Questions & Verified Answers
Stainless steel Stainless steel is commonly used for pump shafts due
to its resistance to corrosion and wear in wastewater
environments.
Pressure relief valve set point 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 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 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 Diffusers are used in aeration tanks to evenly distribute
air or oxygen throughout the water, supporting aerobic
biological processes that treat wastewater.
Lubrication Regular lubrication is essential for pump bearings to
reduce friction and wear, extending the life of the pump
and preventing breakdowns.
Shaft Coupling A shaft coupling connects the motor shaft to the pump
shaft while accommodating slight misalignments and
preventing excessive wear on the components.
Bearing Failure Indication Bearing failure often results in abnormal noises like
grinding or squealing, which indicates the bearings are
worn or damaged.
Strainer Function Strainers are used to filter out large solids from the
water, protecting pumps and other sensitive equipment
from damage or clogging.
Positive Displacement Pump Positive displacement pumps are ideal for high-
pressure applications because they move a fixed
amount of fluid with each cycle, ensuring steady flow at
higher pressures.
Stuvia 2026-2027 | Latest Version
Centrifugal pump A device that moves liquids by transferring kinetic
energy.
Mechanical seal failure A failure that can occur due to overheating, excessive
vibration, and low flow rates.
Air blower A device used to supply oxygen to aerobic processes in
wastewater treatment.
Motor maintenance checks Routine checks that include lubrication of bearings,
voltage and current levels, and alignment with the drive
shaft.
Corrosion prevention in mechanical Typically achieved using stainless steel due to its
components resistance to corrosion.
Pump not priming troubleshooting Checking the pump's discharge valve to ensure it's fully
open.
Cleaning a clogged pump impeller Recommended to remove and manually clean the
impeller with a brush.
Safety precautions with electrical Ensuring the motor is properly grounded to prevent
motors electrical shock.
Mechanical strainer function To filter out solids from liquids in wastewater treatment.
Mechanical strainers 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.
Stuvia 2026-2027 | Latest Version
,CWEA Mechanical Technologist Grade 1 - Certification Exam Questions & Verified Answers
Oil change interval for gear reducers 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 Check valves allow flow in one direction and
automatically close to prevent backflow, protecting
pumps and other equipment from damage.
Cavitation in pumps 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 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 If a pump motor is not starting, the first step should be
starting to check the power supply and ensure electrical
connections are intact and functioning.
Variable frequency drive (VFD) A VFD allows for variable speed operation of pumps,
which helps optimize energy usage based on system
demand, reducing electricity costs.
Cast iron Cast iron is commonly used for pump impellers due to
its strength, wear resistance, and ability to withstand
harsh wastewater conditions.
Sludge conveyor system Sludge conveyors are used to move accumulated
sludge from various treatment processes to the
dewatering area or disposal site.
Running a pump dry 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 Expansion joints are used to absorb the stresses
caused by thermal expansion or contraction in piping
systems, preventing pipe damage or breakage.
Stuvia 2026-2027 | Latest Version
, CWEA Mechanical Technologist Grade 1 - Certification Exam Questions & Verified Answers
Stainless steel Stainless steel is commonly used for pump shafts due
to its resistance to corrosion and wear in wastewater
environments.
Pressure relief valve set point 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 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 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 Diffusers are used in aeration tanks to evenly distribute
air or oxygen throughout the water, supporting aerobic
biological processes that treat wastewater.
Lubrication Regular lubrication is essential for pump bearings to
reduce friction and wear, extending the life of the pump
and preventing breakdowns.
Shaft Coupling A shaft coupling connects the motor shaft to the pump
shaft while accommodating slight misalignments and
preventing excessive wear on the components.
Bearing Failure Indication Bearing failure often results in abnormal noises like
grinding or squealing, which indicates the bearings are
worn or damaged.
Strainer Function Strainers are used to filter out large solids from the
water, protecting pumps and other sensitive equipment
from damage or clogging.
Positive Displacement Pump Positive displacement pumps are ideal for high-
pressure applications because they move a fixed
amount of fluid with each cycle, ensuring steady flow at
higher pressures.
Stuvia 2026-2027 | Latest Version
