Water Treatment Plant Operation Volume 2 Chapter 18

Operators need safety devices to protect themselves and plant equipment from the destructive effects of electricity. This is true because electricity can be hazardous and can cause electric shocks, burns, and even fatalities if proper precautions are not taken. Safety devices such as circuit breakers, fuses, and grounding systems are used to prevent electrical accidents and protect both operators and equipment from potential harm. These devices help to detect and interrupt electrical faults, ensuring the safety of operators and preventing damage to plant equipment.

After lubricating variable speed drives, it is important to wipe excessive grease from sheaves and belts. This is because excessive grease can cause the belts to slip or slide on the sheaves, leading to reduced efficiency and potential damage to the drive system. By wiping off the excess grease, the belts and sheaves can maintain proper traction and function effectively. Therefore, the statement "After lubricating variable speed drives, wipe excessive grease from sheaves and belts" is true.

Recognizing tasks that may be beyond one's capabilities or repair facilities is important for ensuring safety and efficiency. Requesting assistance when needed shows awareness of one's limitations and a willingness to seek help, which can prevent further damage or accidents. This approach promotes a responsible and professional attitude towards problem-solving. Therefore, the given answer "True" is correct.

It is important to replace worn sprockets when replacing a chain because worn sprockets can cause premature wear and damage to a new chain. Sprockets have teeth that engage with the chain, and if these teeth are worn or damaged, they can cause the chain to skip or slip, leading to poor performance and potential safety hazards. By replacing both the chain and the sprockets together, it ensures proper engagement and extends the lifespan of the new chain.

A positive displacement pump, such as a reciprocating or piston type, should never be operated against a closed discharge line because it can cause excessive pressure buildup in the system. This can lead to damage to the pump, pipe, or other components, and may even result in a rupture or explosion. It is important to ensure that there is always an open discharge line or a relief valve to prevent any potential hazards and maintain the proper functioning of the pump.

Chlorine gas is highly reactive and can cause corrosion when it comes into contact with moisture. When chlorine gas reacts with water, it forms hydrochloric acid, which is corrosive to metals and other materials. Therefore, any leakage of chlorine gas in the presence of moisture can result in corrosion. Hence, the statement "Any chlorine gas leakage in the presence of moisture will cause corrosion" is true.

Cleanliness and the elimination of moisture are indeed important requirements for the reliable operation of electrical equipment. Moisture can cause corrosion and short circuits, leading to equipment failure. Similarly, dirt and debris can interfere with the proper functioning of electrical components. Therefore, ensuring cleanliness and preventing moisture ingress into the insulation are crucial for maintaining the performance and longevity of electrical equipment.

Misalignment refers to the condition where the pump and coupling are not properly aligned with each other. This can occur due to various reasons such as improper installation, wear and tear, or excessive vibration. When the pump and coupling are misaligned, it can result in increased stress on the components, reduced efficiency, and potential damage to the equipment. Therefore, misalignment is indeed a major cause of pump and coupling issues.

Bypassing or jumping a fuse means to connect the circuit directly without the fuse in place. Fuses are designed to protect the circuit from excessive current and prevent damage or fire hazards. By bypassing or jumping the fuse, the circuit is left unprotected and can result in overheating, short circuits, and potential damage to the electrical components. Therefore, it is important to never bypass or jump a fuse to ensure the safety of the circuit and the electrical system.

A check valve is a type of valve that allows fluid (in this case, water) to flow in only one direction. It consists of a flap or disc that opens when the fluid flows in the correct direction, and closes to prevent backflow or reverse flow. Therefore, the statement "Check valve allows water to flow in one direction only" is true.

Tap water contains impurities such as minerals and chemicals that can react with the components of a battery. These impurities can cause corrosion and build-up on the electrodes, which can reduce the efficiency and lifespan of the battery. Therefore, using tap water to replace lost water in a battery can indeed shorten its lifespan.

A rod driven into the ground is very effective as a ground because it provides a stable and reliable electrical connection to the earth. When electrical equipment or systems are grounded, it means that they are connected to the earth, which helps to protect against electrical faults and ensures safety. By driving a rod into the ground, it creates a direct path for electrical current to flow into the earth, reducing the risk of electrical shock or damage to equipment. This makes it an effective method for grounding electrical systems.

Pumps should be operated near their rated heads so that they can operate under satisfactory and stable conditions. Operating a pump at its rated head ensures that it is running at its optimal performance level and can deliver the desired flow rate. If a pump is operated at a lower head, it may not be able to deliver the required flow rate, while operating at a higher head can cause excessive strain on the pump and lead to mechanical failures. Therefore, operating a pump near its rated head ensures that it can function efficiently and reliably.

Cooling water from a heat exchanger should not be put back into the potable water system. Potable water refers to water that is safe for human consumption. Cooling water from a heat exchanger may contain contaminants or chemicals that are not safe for drinking. Therefore, it is important to properly dispose of cooling water and ensure that it does not mix with the potable water supply.

Smoking is not promoted at all times during the handling and unloading of carbon and the storage area. Smoking is generally prohibited in areas where flammable materials are present, and carbon can be a flammable material. Therefore, it is not true that smoking is promoted in these situations.

Closing the electrical panel door when testing circuits is important because hot copper sparks could seriously injure you when the circuit is energized and the voltage is high.

A megger is a type of electrical test equipment used to measure the insulation resistance of electrical circuits and motors. It is designed to generate a high voltage, typically 500 to 1000 volts, which is applied to the circuit or motor being tested. This high voltage is used to test the integrity of the insulation, as any leakage current can indicate a potential fault or breakdown in the insulation. Therefore, it is important to deenergize circuits and motors before using a megger to prevent any potential hazards or damage to the equipment.

A good plant maintenance program is important to maintain the successful operation of the plant. This is because regular maintenance helps to prevent breakdowns and equipment failures, ensuring that the plant can operate efficiently and effectively. By implementing a proactive maintenance program, plant managers can identify and address potential issues before they escalate, reducing downtime and increasing productivity. This also helps to extend the lifespan of equipment, saving costs on repairs and replacements. Overall, a well-maintained plant is crucial for achieving optimal performance and meeting production targets.

Operating a positive displacement pump against a closed discharge valve can lead to excessive pressure build-up within the pump, valve, or pipe. This can cause damage to the components and potentially lead to their failure.

Manufacture is the correct answer because they are the ones who have the most detailed knowledge about the equipment they produce. They understand the intricacies of the equipment and can provide specific guidelines and instructions for its maintenance. Contractors may have some knowledge, but they may not have the same level of expertise as the manufacturer. Manufacture professional association and regulatory agency may have general information about equipment maintenance, but they may not have the specific details needed for a particular piece of equipment.

If you're having problems starting a gasoline engine, there are several items that should be checked. These include: carburetor flooded, low compression, no fuel in tank with the valve closed, no spark plug, and water or dirt in fuel lines or carburetor. These are all potential issues that could prevent the engine from starting properly.

A multimeter is a versatile tool used to measure electrical quantities. It can check various parameters such as amps, kilowatt hours, ohms, and voltage. However, in this case, the correct answer is voltage. A multimeter can measure the voltage of an electrical circuit or device, providing information about the potential difference between two points. This measurement is crucial in troubleshooting electrical systems, determining if a circuit is functioning correctly, or identifying potential issues such as voltage drops or fluctuations.

Operators can ensure the accuracy of chemical feed rates by testing and calibrating the chemical feeders. This involves regularly checking the performance of the feeders and adjusting them as necessary to ensure that the correct amount of chemicals is being delivered. Testing and calibration help to maintain accurate and consistent feed rates, which are essential for proper chemical treatment and process control.

Voltage is the electrical pressure available to cause a flow of current in an electrical circuit. It is the force that pushes the electric charges through the circuit. It is measured in volts and is responsible for determining the intensity of the current flowing through the circuit.

A diesel fuel injection pump is a gear driven positive displacement pump. This type of pump is commonly used in diesel engines to deliver fuel at high pressures to the injectors. The gear-driven mechanism ensures precise and consistent fuel delivery, while the positive displacement design allows for a constant flow rate regardless of changes in pressure or viscosity.

A multi meter is a versatile tool that can be used for various purposes. It can be used to check power by measuring voltage, current, and resistance. It can also be used to test for blown fuses by checking for continuity. Additionally, a multi meter can test for grounds by measuring resistance between a circuit and ground. It can test for open circuits by checking for continuity or breaks in a circuit. Lastly, a multi meter can be used to test for single phasing of motors by measuring the voltage across each phase.

Possible causes of a noisy pump could include cavitation, which is the formation and collapse of vapor bubbles in the pump; an insecure foundation, which can cause vibrations and noise; a clogged inlet, which can disrupt the flow and create noise; mechanical defects in the pump, such as misalignment or worn-out parts; and a worn impeller, which can cause imbalance and noise during operation.

Emergency procedures must be established for operators to follow in case of various emergencies. These emergencies can be caused by broken transmission lines for distribution mains, power outages, the release of chlorine gas, the release of hazardous or toxic chemicals into the raw water supply, or a terrorist attack. It is important for operators to have clear protocols and guidelines in place to handle these situations effectively and ensure the safety of the public and the environment.

During operational checks on an electrical motor, several unusual conditions could be encountered. Brush chatter refers to the rapid movement or vibration of the motor's brushes, which could indicate a problem with the brush holders or springs. Intermittent sparking at brushes could suggest poor contact or worn-out brushes. If the motor or bearing feels or smells hot, it could indicate overheating due to excessive friction or insufficient lubrication. Noises and vibrations are also abnormal conditions that could indicate issues with the motor's bearings, misalignment, or imbalance.

Cavitation occurs in a pump due to unusually low pressures within the pump. Cavitation happens when the pressure in the pump drops below the vapor pressure of the liquid being pumped, causing the formation of vapor bubbles. These bubbles then collapse when they reach higher pressure areas, causing damage to the pump components. Therefore, when the pressure within the pump is unusually low, cavitation can occur.

Shear pins are used as a protective device to prevent damage in case of sudden overloads. When excessive force or load is applied to a machine or equipment, the shear pin is designed to break or shear off, sacrificing itself to protect the more expensive or critical components. This helps to prevent further damage to the equipment and ensures the safety of the system.

Gate valves are commonly used to control flows. This is because gate valves provide a straight-through flow path when fully open, allowing for minimal pressure drop. They are often used in applications where a full flow or shut-off is required, such as in water treatment plants, oil and gas pipelines, and industrial processes. Gate valves are known for their durability and ability to handle high pressures and temperatures, making them a popular choice for flow control in various industries.

An imbalanced current can cause uneven heating in a motor, which can lead to overheating and damage to the insulation. This can shorten the lifespan of the motor and result in frequent breakdowns or the need for replacement. Additionally, imbalanced current can also cause other issues such as vibration and wear in the motor, further reducing its efficiency and reliability.

The primary use of a butterfly valve is as a control valve. This type of valve is used to regulate the flow of fluid or gas in a system. It is designed with a disc that rotates to either fully open or fully close the valve, allowing for precise control of the flow rate. Butterfly valves are commonly used in industries such as oil and gas, water treatment, and HVAC systems. They are preferred for their simple design, compact size, and cost-effectiveness.

Opening an electrical circuit is not like opening a valve on a water pipe. While opening a valve on a water pipe allows water to flow through, opening an electrical circuit breaks the flow of electricity. So, the statement is false.

Fuses are used to protect the main control panel and wiring from damage caused by excessive voltage and amperage. When the current flowing through a circuit exceeds the rated value of the fuse, the fuse will melt and break the circuit, preventing further damage. Fuses are designed to be the weak link in the circuit, sacrificing themselves to protect the more expensive and sensitive components. By breaking the circuit, fuses prevent excessive voltage and amperage from reaching the control panel and wiring, thus protecting them from potential damage.

If back spending, which is the reverse flow of fluid, is observed in a pump with a check valve stopped, closing the pump discharge valve slowly would be the appropriate action. This is because closing the valve slowly would help to gradually reduce the flow and pressure, preventing any sudden surges or damage to the system.

The operator should check for an area full of water, burnt wires, a coil that is burned, loose contacts, and loose wires when troubleshooting any motor control that has developed trouble.

The common symptoms of improper chain drive operation include broken pins and rollers, where the chain components have become damaged or broken. The chain climbing sprockets is another symptom, indicating that the chain is not properly engaging with the sprockets and is slipping or jumping. The chain clinging to sprockets is also a sign of improper operation, where the chain is not releasing from the sprockets as it should. Chain whip refers to the excessive movement or flapping of the chain, indicating a lack of tension or alignment. Finally, excessive noise is a symptom of improper chain drive operation, suggesting that there may be issues with the chain or sprockets causing friction or misalignment.

Excessive back pressure, improper compression pressure, an adequate fuel flow, low oil pressure, and misfiring cylinders can all contribute to a reduction in diesel engine performance. Excessive back pressure occurs when the exhaust gases cannot escape properly, leading to reduced power output. Improper compression pressure can result in weak combustion and decreased engine efficiency. An adequate fuel flow is necessary for proper combustion and power generation. Low oil pressure can lead to insufficient lubrication, causing increased friction and wear on engine components. Misfiring cylinders can result in uneven power delivery and reduced overall engine performance.

Before starting a pump, several tasks should be performed. First, it is important to check the electrical voltage with the motor's characteristics to ensure compatibility. Next, the alignment of the pump shaft and the motor should be checked to prevent any misalignment issues. Additionally, the pump should be lubricated according to the provided instructions to ensure smooth operation. It is also crucial to verify that the thermal overload units in the starter are set properly to avoid any overheating problems. Lastly, the shaft should be turned by hand to ensure that it rotates freely, indicating that there are no obstructions or mechanical issues.

Misalignment of couplings can be caused by several factors. Excessive bearing wear can lead to misalignment as it affects the smooth rotation of the coupling. Excessive floor loading can also cause misalignment, as it puts additional stress on the equipment and can cause it to shift out of alignment. Improper original installation of equipment can result in misalignment if the coupling is not installed correctly from the beginning. Settling of foundations can cause the equipment to shift and become misaligned. Warping of bases can also lead to misalignment as it affects the stability and alignment of the equipment.

Gate valves require several types of maintenance. First, the gearing of the valve needs to be lubricated to ensure smooth operation. Second, the rising stem threads also need lubrication to prevent any sticking or difficulty in opening or closing the valve. Third, the valve itself needs to be operated regularly to prevent any seizing or sticking. Fourth, if there are any leaky gate valve seats, they need to be refaced to ensure a proper seal. Lastly, the packing of the valve may need to be replaced if it is worn or damaged.

Diesel fuel can be stored for years without deteriorating if proper storage methods are followed. Diesel fuel has a longer shelf life compared to gasoline because it is more stable and less volatile. However, it is still important to store diesel fuel in a cool, dry, and well-ventilated area to prevent contamination and degradation. Additionally, using fuel stabilizers and periodically rotating the fuel can help maintain its quality over time. Therefore, the statement that diesel fuel cannot be kept in storage for years without deteriorating is false.

The Megger is a device that is used to measure insulation resistance. It is commonly used to check the insulation resistance on branch circuit wiring, busbar systems, feeders, grounds, and motors. This device helps to ensure that the insulation on these items is intact and functioning properly, which is crucial for the safety and efficiency of electrical systems.

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Grease and pump anti-friction bearings not only protect steel elements against friction but also against corrosion. They create a barrier between the steel surfaces, preventing direct contact and reducing friction. Additionally, the grease used in these bearings often contains corrosion inhibitors, which further protect the steel from rust and corrosion. Therefore, the statement that their main job is to protect against friction only is incorrect.

Standby power can be provided at a water treatment plant through various methods. One way is by using an engine driven generator set, which can generate electricity to power the plant in case of a power outage. Another option is to use batteries, which can store electrical energy and provide power when needed. Additionally, the plant can be connected to an alternate power source, such as a backup power grid or a renewable energy system, to ensure continuous operation. These methods ensure that the plant can maintain functionality even during power disruptions.

Inadequate tension in the belt can cause slipping and excessive wear, leading to a shorter lifespan. Incorrect alignment can cause the belt to run at an angle, causing uneven wear and premature failure. Oil on the belts can reduce friction and cause slippage, leading to increased wear. Replacing only one V belt on a multiple drive can cause an imbalance in the system, leading to excessive strain on the remaining belts and a shorter lifespan.

The items listed in the answer are all common forms of stored energy. Compressed gases stored under pressure contain potential energy that can be released when the pressure is released. Electrical energy is stored in batteries or capacitors and can be converted into other forms of energy. Hydraulic pressure stores energy in the form of pressurized fluid, which can be used to do work. Spring-loaded equipment stores potential energy in the compressed spring, which can be released to perform tasks.