Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
111 Cards in this Set
- Front
- Back
|
Why should you plan a good maintenance program for your treatment plant?
|
A good maintenance program is essential to maintain successful operation of the treatment plant.
|
|
|
What general items would you include in your maintenance program?
|
A successful maintenance program will include everything from mechanical equipment to the care of the plant grounds, buildings, and structures.
|
|
|
Why should you have a good record keeping system for your maintenance program?
|
A good recordkeeping system tells when maintenance is due and provides a record of equipment performance. Poor performance is a good justification for replacement or new equipment. Good records also help keep your warranty in force.
|
|
|
What is the difference between an equipment service card and a service record card?
|
An equipment service card tells what service or inspection work should be done on a piece of equipment and when, while the service record card is a record of what was done and when.
|
|
|
Prepare a list of emergency phone numbers for your treatment plant.
|
Emergency phone numbers for a treatment plant should include the phone numbers for police, fire, hospital or physician, responsible plant officials, local emergency disaster office, emergency team, and CHEMTREC, (800) 424-9300.
|
|
|
Why is it necessary to bleed down pressurized systems before making repairs?
|
Stored energy must be bled down to prevent its sudden release, which could injure an operator working on the system or equipment.
|
|
|
Why must unqualified or inexperienced people be extremely careful when attempting to troubleshoot or repair electrical equipment?
|
Unqualified or inexperienced people must be extremely careful when attempting to troubleshoot or repair electrical equipment because they can be seriously injured and damage costly equipment if a mistake is made.
|
|
|
What could happen when machinery is not shut off, locked out, and tagged properly?
|
When machinery is not shut off, locked out, and tagged properly, the following accidents could occur: 1. Maintenance operator could be cleaning pump and have it start, thus losing an arm, hand, or finger. 2. Electric motors or controls not properly grounded could lead to possible severe shock, paralysis, or death. 3. Improper circuits such as a wrong connection, safety devices jumped, wrong fuses, or improper wiring can cause fires or injuries due to incorrect operation of machinery.
|
|
|
How can you determine the proper voltage and allowable current in amps for a piece of equipment?
|
The proper voltage and allowable current in amps for a piece of equipment can be determined by reading the nameplate information or the instruction manual for the equipment.
|
|
|
What are the two types of current?
|
The two types of current are direct current (DC) and alternating current (AC).
|
|
|
Amperage is the measurement of what?
|
Amperage is the measurement of current or electron flow and is an indication of work being done or how hard the electricity is working.
|
|
|
How can you determine if there is voltage in a circuit?
|
You test for voltage by using a multimeter.
|
|
|
What are some of the uses of a multimeter?
|
A multimeter can be used to test for voltage, open circuits, blown fuses, single phasing of motors, and grounding.
|
|
|
What precautions should be taken before attempting to change fuses?
|
Before attempting to change fuses, turn off power and check both power lines for voltage. Use a fuse puller.
|
|
|
How do you test for voltage with a multimeter when the voltage is unknow?
|
If the voltage is unknown and the multimeter has different scales that are manually set, always start with the highest voltage range and work down. Otherwise, the multimeter could be damaged.
|
|
|
What could be the cause of amp reading different from the nameplate rating?
|
Amp readings different from the nameplate rating could be caused by low voltage, bad bearings, poor connections, or excessive load.
|
|
|
How often should motors and wirings be megged?
|
Motors and wiring should be megged at least once a year, if possible.
|
|
|
An ohmmeter is used to measure the resistance (ohms) in what control circuit components?
|
An ohmmeter is used to measure the resistance (ohms) in control circuit components such as coils, fuses, relays, resistors, and switches.
|
|
|
What are two types of safety devices found in main electrical panels or control units?
|
The two types of safety devices in main electrical panels or control units are fuses or circuit breakers.
|
|
|
What are fuses used to protect?
|
Fuses are used to protect operators, wiring, circuits, heaters, motors, and various other electrical equipment.
|
|
|
Why must a fuse never be bypassed or jumped?
|
A fuse must never be bypassed or jumped because the fuse may be the only protection the circuit has; without it, serious damage to equipment and possible injury to operators can occur.
|
|
|
How does a circuit breaker work?
|
A circuit breaker is a switch that is opened automatically when the current or the voltage exceeds or falls below a certain limit. Unlike a fuse that has to be replaced each time it blows, a circuit breaker can be reset after a short delay to allow time for cooling.
|
|
|
How are motor starters controlled?
|
Motor starters can be either manually or automatically controlled.
|
|
|
When are magnetic starters used?
|
Magnetic starters are commonly used to start pumps, compressors, blowers, and anything where automatic or remote control is desired.
|
|
|
How is electrical energy converted into mechanical energy?
|
Electrical energy is commonly converted into mechanical energy by electric motors.
|
|
|
What are the important parts of an electric motor?
|
An electric motor usually consists of a stator, rotor, end bells, and windings.
|
|
|
How can motors be kept trouble free?
|
Motors can be kept trouble free with proper lubrication and maintenance.
|
|
|
What should be done with motor nameplate data?
|
Motor nameplate data should be recorded, compared with manufacturer's data sheet and instruction manual for consistency, and placed in a file for future reference. Many times the nameplate is painted, corroded, or missing from the unit when the information is needed to repair the motor or replace parts.
|
|
|
What is the key to effective troubleshooting?
|
The key to effective troubleshooting is practical, step-by-step procedures combined with a commonsense approach.
|
|
|
What are some of the steps that should be taken when troubleshooting magnetic starters?
|
When troubleshooting magnetic starters: Gather preliminary information. Inspect: contacts, mechanical parts, and magnetic parts.
|
|
|
What kind of information should be recorded regarding electrical equipment?
|
Information that should be recorded regarding electrical equipment includes nameplate data and every change, repair, and test.
|
|
|
Why should a qualified electrician perform most of the necessary maintenance and repair of electrical equipment?
|
A qualified electrician should perform most of the necessary maintenance and repair of electrical equipment to avoid endangering lives and to avoid damage to equipment.
|
|
|
What is the purpose of a kirk-key system?
|
The purpose of a kirk-key system (one key is used for two locks) is to ensure proper connection of standby power into your power distribution system. The commercial power system must be locked out by the use of switchgear before the standby power is connected to your power distribution system.
|
|
|
Why are battery-powered backup lighting units considered better than engine-driven power sources?
|
Battery-powered backup lighting units are considered better than engine-driven power sources because they are more economical. If you have a momentary power outage, the system responds without an engine-generator startup.
|
|
|
Why should the water lost from a lead-acid battery be replaced with deionized or distilled water?
|
If water lost from a lead-acid battery is replaced with tap water, the impurities in the water will become attached to the lead plates and shorten the life of the battery.
|
|
|
Why is electricity transmitted at high voltage?
|
Electricity is transmitted at high voltage to reduce the size of transmission lines.
|
|
|
What precautions must be taken if outdoor transformers have exposed high-voltage wires?
|
If outdoor transforms have exposed high-voltage wires, the following precautions must be taken: An 8-foot-high (2.4 m) fence is required to prevent accessibility by unqualified or unauthorized persons. Signs attached to the fence must indicate: “High Voltage.”
|
|
|
What kind of maintenance should a treatment plant operator perform on the switch gear?
|
The treatment plant operator must keep the exterior and surroundings of the switchgear clean.
|
|
|
What symptoms indicate that a power distribution transformer may be in need of maintenance or repair?
|
Symptoms that a power distribution transformer may be in need of maintenance or repair include unusual noises, high or low oil levels, oil leaks, or high operating temperatures.
|
|
|
What is the purpose of an electrical safety checklist?
|
Electrical safety checklists are used to make operators aware of potential electrical hazards in their water treatment plant.
|
|
|
Why are rusted conduits of concern to a water treatment plant operator?
|
Rusted conduits are of concern because they could become the source of a spark that could cause an explosion.
|
|
|
List the pieces of equipment and special tools commonly found in a pump repair shop.
|
Pieces of equipment and special tools commonly found in a pump repair shop include welding equipment, lathes, drill press and drills, power hacksaw, flame-cutting equipment, micrometers, calipers, gauges, portable electric tools, grinders, a forcing press, metal-spray equipment, and sandblasting equipment.
|
|
|
What is the purpose of a pump impeller?
|
The purpose of a pump impeller is to suck water in the suction piping and to throw water out between the impeller blades.
|
|
|
Why should the intake end of suction piping have a suitable screen?
|
A suitable screen should be installed on the intake end of suction piping to prevent foreign matter (sticks, refuse) from being sucked into the pump and clogging or wearing the impeller.
|
|
|
Why must suction piping alway be up-sloping?
|
Suction piping must be up-sloping to prevent air pockets from forming in the top of a pipe where air could be drawn into the pump and cause the loss of suction.
|
|
|
What is cavitation?
|
Cavitation is a condition that occurs when the pressure within the flowing water drops very low, the water starts to boil, and gas pockets or bubbles form on the blade of the impeller. The collapse of these gas pockets or bubbles drives water into the impeller with a terrific force that can knock metal particles off the impeller and cause pitting on the impeller surface this same action can and does occur on pressure reducing valves and partially closed gate and butterfly valves. Cavitation is accompanied by loud noises that sound like someone is pounding on the impeller with a hammer.
|
|
|
What is an advantage of a double-suction pump over a single-suction pump?
|
An advantage of a double-suction pump over a single-suction design is that the longitudinal thrust from the water entering the impeller is balanced.
|
|
|
What is the purpose of lubrication?
|
The purpose of lubrication is to reduce friction between two surfaces and to remove heat caused by friction.
|
|
|
What happens to oils in service?
|
Oils in service tend to become acid (contaminated) and may cause corrosion, deposits, sludging, and other problems.
|
|
|
What should be done to ensure proper lubrication of equipment.
|
To ensure proper lubrication of equipment, determine the proper lubrication schedule, lubricant, and amount of lubricant, and prepare a lubrication chart.
|
|
|
Does a soft grease have a high or low viscosity index as compared with a hard grease?
|
A soft grease has a low viscosity index as compared with a hard grease.
|
|
|
Is oil or grease used with higher speeds?
|
Oil is used with higher speeds.
|
|
|
What problems can result from overfilling with oil or grease?
|
Overfilling with oil or grease can result in high pressures and temperatures, and ruined seals or other components.
|
|
|
What is a cross-connection?
|
A cross-connection is a connection between a drinking (potable) water system and an unapproved water supply.
|
|
|
Is a slight water-seal leakage desirable when a pump is running? If so, why?
|
A slight water-seal leakage is desirable when a pump is running to keep the packing cool and in good condition.
|
|
|
How would you measure the capacity of a pump?
|
To measure the capacity of a pump, measure the volume pumped during a specific time period. Pump Capacity, GPM = Volume, gallons/time, minutes.
|
|
|
What should be done to a pump before it is shut down for a long time, and why?
|
Before a prolonged shutdown, the pump should be drained to prevent damage from corrosion, sedimentation, and freezing. Also,the motor disconnect switch should be opened to disconnect the motor.
|
|
|
What are some of the common causes of shear pin failure in reciprocating pumps?
|
Shear pins commonly fail in reciprocating pumps because of a solid object lodged under piston, a clogged discharge line, or a stuck or wedged valve.
|
|
|
What may happen when water or a thin sludge is being pumped by a reciprocating pump?
|
A noise may develop when a reciprocating pump is pumping this sludge due to water hammer, but is will disappear when heavy sludge is pumped.
|
|
|
What could be the causes of a higher than normal discharge pressure in a progressive cavity pump?
|
Higher than normal discharge pressures in a progressive cavity pump may indicate a line blockage or a closed valve downstream.
|
|
|
What are the major items you would include when checking an electric motor?
|
When checking an electric motor, the following items should be checked periodically, as well as when trouble develops: motor conditions, note all unusual conditions, lubricate bearings, listen to motor, and check temperature.
|
|
|
What is the purpose of a stethoscope?
|
The purpose of a stethoscope is to magnify sounds and carry them to the ear. This instrument is used to detect unusual sounds in electric motors such as whines, gratings, or uneven noises.
|
|
|
How can you tell if a V-belt on belt-drive equipment has proper tension and alignment?
|
A properly adjusted V-belt has a slight bow in the slack side when running. When idle, it has an alive springiness when thumped with the hand. To check for proper alignment, lay a long straightedge or string across outside faces of the pulley, and allow for differences in dimensions from centerlines of grooves to outside faces of the pulleys being aligned. Be very careful in aligning drives with more that one V-belt on a sheave, as misalignment can cause unequal tension.
|
|
|
Why should worn sprockets be replaced when replacing a chain in a chain drive unit?
|
Always replace worn sprockets when replacing a chain in a chain drive unit because out-of-pitch sprockets cause as much chain wear in a few hours as years of normal operation.
|
|
|
What factors could cause couplings to become out of alignment?
|
Improper original installation of equipment, settling of foundations, heavy floor loading, warping of bases, and excessive bearing wear could cause couplings to become out of alignment.
|
|
|
What is the purpose of shear pins?
|
A shear pin is a straight pin that will fail (break) when a certain load or stress is exceeded. The purpose of the pin is to protect equipment from damage due to excessive loads or stresses.
|
|
|
Where would you find out how to lubricate a pump?
|
Pumps must be lubricated in accordance with the manufacturer's recommendations. Quality lubricants should be used.
|
|
|
What problems can develop if too much grease is used in lubricating a motor?
|
In lubricating motors, too much grease may cause bearing trouble or damage the winding.
|
|
|
What items would you check if a pump will not start?
|
If a pump will not start, check for blown fuses or tripped circuit breakers and the cause. Also check for a loose connection, fuse, or thermal unit.
|
|
|
How would you attempt to increase the discharge from a pump if the flow rate is lower than expected?
|
To increase the rate of discharge from a pump, you should look for something causing the reduced rate of discharge, such as pumping air, motor malfunction, plugged lines or valves, impeller problems, or other factors.
|
|
|
Why should a pump that has been locked or tagged out for maintenance or repairs not be started?
|
If a pump that has been locked or tagged out for maintenance or repairs is started, an operator working on the pump could be seriously injured and equipment could be damaged.
|
|
|
Under what conditions might a centrifugal pump be started against a closed discharge valve?
|
Normally, a centrifugal pump should be started after the discharge valve is opened. Exceptions are treatment processes or piping systems with vacuums or pressures that cannot be dropped or allowed to fluctuate greatly while an alternate pump is put on the line.
|
|
|
What should be done before stopping an operating pump?
|
Before stopping an operating pump, start another pump (if appropriate). Inspect the operating pump by looking for developing problems, required adjustments, and problem condition of the unit.
|
|
|
What could cause a pump shaft or motor to spin backward?
|
A pump shaft or motor will spin backward if water being pumped flows back through the pump when the pump is shut off. This will occur if there is a faulty check valve or foot valve in the system.
|
|
|
Why should the position (open or closed) of all valves be checked before starting a pump?
|
The position of all valves should be checked before starting a pump to ensure that the water being pumped will go where intended.
|
|
|
What is the most important rule regarding the operation of positive-displacement pumps?
|
The most important rule regarding the operation of positive-displacement pumps is to never operate the pump against a closed valve, especially a discharge valve.
|
|
|
What could happen if a positive-displacement pump is operated against a closed discharge valve?
|
If a positive-displacement pump is operated against a closed discharge valve, the pipe, valve, or pump could rupture from excessive pressure. The rupture will damage equipment and possibly seriously injure or kill someone standing nearby.
|
|
|
Why should both ends of a sludge line never be closed tight at the same time?
|
Both ends of a sludge line should never be closed tight at the same time because gas from decomposition of the sludge can build up and rupture pipes or valves.
|
|
|
List some of the uses of a compressor in connection with operation and maintenance of a water treatment plant.
|
Compressors are used to activate and control pump control systems (bubblers), valve operators, and water pressure systems. They are also used to operate portable pneumatic tools, such as jackhammers, compactors, air drills, sandblaster, tapping machines, and air pumps.
|
|
|
How often should the suction filter of a compressor be cleaned?
|
The frequency of cleaning a suction filter on a compressor depends on the use of the compressor and the atmosphere around it. The filter should be inspected at least monthly and cleaned or replaced every 3-6 months. More frequent inspection, cleaning, and replacement are required under dusty conditions such as near jackhammer operation on a street.
|
|
|
How often should compressor oil be changed?
|
Compressor oil should be changed at least every 3 months, unless the manufacturer states differently, if there are filters in the oil system, these also should be changed.
|
|
|
How often should the condensate from the air receiver be drained?
|
Drain the condensate from the air receiver daily.
|
|
|
What must be done before testing belt tension on compressors with your hands?
|
Before testing belt tension on a compressor with your hands, make sure the compressor is locked off.
|
|
|
What is the purpose of valves?
|
Valves are the controlling devices placed in piping systems to stop, regulate, check, divert, or otherwise modify the flow of liquids or gases.
|
|
|
List six common types of valves found in water treatment facilities.
|
Six common types of valves found in water treatment facilities include gate valves, globe valves, eccentric valves, butterfly valves, check valves, and automatic valves.
|
|
|
What maintenance is required by gate valves?
|
The most common maintenance required by gate valves is oiling, tightening, or replacing the stem stuffing box packing.
|
|
|
What is the purpose of a check valve?
|
The purpose of the check valve is to allow water to flow in one direction only.
|
|
|
Why is backflow prevention by check valves essential in many applications?
|
Backflow prevention by check valves is essential in many applications to prevent pumps from reversing when power is removed, to protect water systems from being cross-connected, to aid in pump operation as a dampener, and to ensure full-pipe operation (pipe is full of water)
|
|
|
List some possible uses of gasoline engines in water treatment plants.
|
Gasoline engines may be used in water treatment plants to drive pumps, generators, tractors, and vehicles.
|
|
|
What items would you check if you had problems starting a gasoline engine?
|
If a gasoline engine will not start, check the following items: no fuel in tank, valve closed, carburetor not choked, water or dirt in fuel lines or carburetor, carburetor flooded, low compression, loose spark plug, or no spark at plug.
|
|
|
What items could cause a gasoline engine to not run properly?
|
A gasoline engine may not run properly if the engine misses, surges, stops, overheats, knocks, or backfires through carburetor.
|
|
|
If a gasoline engine will not start and the spark plug is wet with fuel or oil, what has happened?
|
If a gasoline engine will not start and the spark plug is wet with fuel or oil, this could indicate that the cylinder is flooded with fuel from having the choke on too long.
|
|
|
If a gasoline engine will not start and there is an oil residue on the spark plug, what has happened?
|
If a gasoline engine will not start and there is an oil residue on the spark plug, this could indicate worn piston rings.
|
|
|
After an engine has started, what should be done before applying the load?
|
After an engine has started, give it an opportunity to warm up before applying the load.
|
|
|
Why is gasoline not used as a fuel in diesel engines?
|
Gasoline is not used as a fuel in diesel engines because it would start to burn from the heat generated by compression before the piston reached the top ot the stroke.
|
|
|
List the four basic parts of a diesel fuel system.
|
The four basic parts of a diesel fuel system are: primary fuel filter, secondary fuel filter, fuel injection pump, and fuel injector.
|
|
|
What is the purpose of the fuel injection pump?
|
The purpose of the fuel injection pump is to deliver fuel to the injector at a very high pressure.
|
|
|
How is heat removed from the cylinders in a water-cooled engine?
|
Heat is removed from the cylinders by a water cooling system. Each cylinder is surrounded with a water jacket through which the coolant (water) circulates. This is accomplished by a water pump that is belt driven from the crankshaft.
|
|
|
The storage and use of fuels for internal combustion engines must be in accordance with what codes?
|
The storage and use of fuels for internal combustion engines must be in accordance with local building and fire codes.
|
|
|
List four types of fuel commonly used by internal combustion engines.
|
Four types of fuels commonly used by internal combustion engines are diesel, gasoline, liquefied petroleum gas (LPG), and natural gas.
|
|
|
How often should standby internal combustion engines be test run when not in regular service?
|
Standby internal combustion engines not in regular service should be started up and test run at least once a week.
|
|
|
Under what conditions should standby engines be test run?
|
Standby engines should be test run long enough for the engine to come up to its normal operating temperature. If at all possible, the engine should be run under its normal load
|
|
|
How can an operator locate information on how to operate, control, and maintain chemical feeders.
|
Information on how to operate, control, and maintain chemical feeders may be found in the feeder manufacturer’s literature.
|
|
|
List three common types of chemical feeders.
|
The three common types of chemical feeders are solid feeders, liquid feeders, and gas feeders.
|
|
|
Why should chlorine leaks be detected and repaired?
|
Chlorine is toxic to humans and will cause corrosion damage to equipment.
|
|
|
How would you search for chlorine leaks?
|
Large chlorine leaks can be detected by smell. Small leaks are detected by soaking a cloth with ammonia water and holding the cloth near areas where leaks might develop. A white cloud will indicate the presence of a leak.
|
|
|
How often should tanks and reservoirs be drained and inspected?
|
Tanks and reservoirs should be drained and inspected at least once every 5 years if the interior is well protected, more often it it is not well protected.
|
|
|
Why must the groundwater level be below the bottom of a tank before it is drained?
|
The groundwater level should be below the bottom of a tank before it is drained so the tank will not float on the groundwater when empty or develop cracks from groundwater pressure.
|
|
|
What is an alternative to applying a protective coating to prevent corrosion of a steel tank?
|
Cathodic protection is an alternative to applying a protective coating to prevent corrosion of a steel tank.
|
|
|
What factors influence the type of building maintenance program that might be needed for your water treatment plant?
|
Factors that influence the type of building maintenance program needed by a water treatment plant include the age, type, and use of each building.
|
|
|
What items should be included in a building maintenance program?
|
A building maintenance program will keep the building in good shape and includes painting, when necessary. Attention also must be given to electrical systems, plumbing, heating, cooling, ventilating, floors, windows, roofs, and drainage around the buildings. The building should be kept clean, tools should be stored in their proper place, and essential storage should be available.
|
