Lift Stations Flashcards
Exam Questions to Study
True or False Questions: The greater the velocity of flow in pipes, the smaller the friction losses.
FALSE
True or False Questions: When using pumps that are NOT self priming the wet well levelshould be drawn down below the centerline of the pump impeller
FALSE
True or False Questions: Mechanical seals have stuffing boxes.
True
True or False Questions: If a Communications interface is made with programmable logic controllers (PLCs) at other stations the PLC can become the front end of a simple Supervisory Control and Data Acquisition (SCADA) system
True
True or False Questions: One of an operator’s jobs is to tell Engineers how to design lift stations
False
True or False Questions:
If the rotation of an impeller of a centrifugal pump is in the wrong direction, the amp reading will be higher than the motor rating due to more work being done by the pump by rotating backward.
False
What is the most important requirement of a lift station?1)Economics
2) Operation and maintenance 3)Reliability
4) Safety
Reliability
A ground fault circuit interrupter GFCI is designed to limit electric shock to a current and time duration value below what level?
1) That which can cause ignition of clothing
2) That which can create minor pain sensations
3) That which can pass through your body
4) That which can produce serious injury.
That which can produce Serious injury.
What happens when a seal fails on a submersible pump?
1) Waste water that flows into the portable water supply and contaminates the water
2) Waste Water leaks into the driveway and can cause electrical outages number
3) Waste water overflows the seal and causes adverse environmental impacts
4) Wastewater penetrates the motor compartment and burns and shorts out the motor.
Wastewater penetrates the motor compartment in Burns and shorts out the motor.
Why should large horizontal centrifugal pumps have a vent valve on top of the Volute?
1) For priming purposes
2) For purpose of preventing water hammer
3) to prevent formation of vacuum
4) To release entrained air
For priming purposes
What is the main purpose of gate valves in a lift station?
1) To check the pump efficiency on the pump curve 2) To function as a check valve went to check valves fail
3) To isolate the pump from the force main during pump or check valve maintenance
4) To throttle pump flows to avoid overloading the sewer system.
To isolate the pump from the Force main during pump or check valve maintenance.
Why should operation and maintenance operators be given the opportunity to review the prints and specifications of a new lift station before the award of a contract for new construction?
1) to allow operators to learn how to design lift stations.
2) to be sure adequate Provisions have been made for the station to be easily and properly operate and maintained
3) to commit on the reliability of the specified equipment manufacturers
4) to promote communication between design Engineers operation and maintenance operators.
To be sure adequate Provisions have been made for the station to be easily and properly operated & maintained.
What is the most significant factor in determining the frequency of lift station visits?
1) attitude of operating agency 2) compliance with regulatory permits
3) potential for nuisances
4) type of Wastewater being conveyed
1) attitude of operating agency
What is the critical period of time if a lift station does fail?The length of time from when the failure occurs
1) at current pumping level until all pop start to lower water level number.
2) at high water level in the wet well to win back up flooding or overflows will occur
3) until emergency crew can arrive at lift station
4) until public notifies collection system agency
2) at high water level in the wet well to win back up flooding or overflows will occur
Where should lift station operation and maintenance records be filed?
1) At the agency’s main office
2) At the cruise locker room
3) in the crews vehicle binder
4) in the lift station book
1) At the agency’s main office
Multiple choice:
What can happen when a lift station or Force main fails?
1) newspaper headlines can tarnish the image of the collection system Agency 2)significant impact on environment number
3) Wastewater can back up into homes
4) Waste Water can be discharged into rivers
5) Wastewater will have to flow within the sewers
1) newspaper headlines can tarnish the image of the collection system Agency 2)significant impact on environment number
3) Wastewater can back up into homes
4) Waste Water can be discharged into rivers
Multiple choice:
Why should collection system operators help Engineers design lift stations?
1) to allow Engineers time to design other lift stations
2)to gain important experience designing lift stations
3) to improve operation and maintenance of lift stations
4)to lower operating cost of lift stations
5) to minimize bypasses and backups caused by lift station failures
3) to improve operation and maintenance of lift stations
4) to lower operating cost of lift stations
5) to minimize bypasses and backups caused by lift station failures
Mutiple choice:
What stations are installed at low points in the collection system and at the end of gravity sewers where what kinds of conditions exist?
1) Community concerns regarding potential power outages
2) Excavation cost to maintain gravity flow and sufficient velocity become excessive
3) groundwater today was too high for installing deep sewers 4) homeowners are requesting an aesthetically pleasing lift station structure
5) Soil stability is unstable for trenching
2) Excavation cost to maintain gravity flow and sufficient velocity become excessive
3) groundwater today was too high for installing deep sewers
5) Soil stability is unstable for trenching
Multiple choice: What must operators control at a lift station to prevent the lift station from being a nuisance to nearby neighbor? 1) appearances 2) health hazards 3) noise 4) odors 5) safety hazards
1) appearances
2) health hazards
3) noise
4) odors
5) safety hazards
Multiple choice: Why do Force Mains need air and vacuum release valves? to avoid 1) decrease in friction losses 2) deposition of solids 3) flows reversing direction 4) increase in pumping cost 5) reduction and pipe capacity
4) increase in pumping cost
5) reduction and pipe capacity
Multiple choice: If lift station piping and pumps or improperly designed what types of problems can develop? 1) bearing failures 2) cavitation 3) excessive maintenance 4) insufficient pumping capacity 5) vibrations
2) cavitation
3) excessive maintenance
4) insufficient pumping capacity
5) vibrations
Multiple choice: What types of float controllers are used to start and to stop pumps? 1) bottle floats 2) cable attach floats 3) cork floats 4) mercury switch float controls 5) Rod attached floats
2) cable attach floats
4) mercury switch float controls
5) Rod attached floats
Multiple choice:
What are the advantages of mechanical seals over packing seals?
1) initial cost is sufficiently lower than conventional packing
2) leakage of raw sewage is eliminated
3) less power consumption than with packing
4) less wear on the pump Shaft or shaft sleeve than with packing
5) virtually maintenance-free
2) leakage of raw sewage is eliminated
3) less power consumption than with packing
4) less wear on the pump Shaft or shaft sleeve than with packing
5) virtually maintenance-free
Multiple choice: Which factors influence head loss in a pipe? 1) cavitation 2)corrosion 3) sediment 4) slime growths 5) total dynamic head
2) corrosion
3) sediment
4) slime growths
5) total dynamic head
Multiple choice:
What safety hazards can be encountered in a lift station ?
1) dangerous electrical gear
2) explosive or toxic gases
3) inadequate drainage
4) insufficient oxygen
5) poor footing caused by grease or slimes
1) dangerous electrical gear
2) explosive or toxic gases
3) inadequate drainage
4) insufficient oxygen
5) poor footing caused by grease or slimes
Multiple choice:
Frequency of lift station visits depends on what factors?
1) Adequacy of preventive maintenance and overhaul program
2) condition of the equipment 3) design of facility and Equipment installed
4) potential damage resulting from storms flooding stations
5) type of adequacy and
reliability, of the telemetry system.
1) Adequacy of preventive maintenance and overhaul program
2) condition of the equipment 3) design of facility and Equipment installed
4) potential damage resulting from storms flooding stations
5) type of adequacy and
reliability, of the telemetry system.
Multiple choice:
What types of lift station failures may be found during a lift station visit?
1) Air-bound pump
2) Blocked check valve
3) Failure of water level sensing equipment
4) Plugged pump impeller
5) Tripped-out motor thermal
1) Air-bound pump
2) Blocked check valve
3) Failure of water level sensing equipment
4) Plugged pump impeller
5) Tripped-out motor thermal
Multiple Choice:
Preparation of a lift station maintenance program requires consideration of what important factors?
1) Budgetary considerations
2) knowledge gained from experience
3) recommendations of equipment manufacturers
4) regulatory regulations
5) requirements of lift station
2) knowledge gained from experience
3) recommendations of equipment manufacturers
5) requirements of lift station
