safety - vchs cte · 2019. 1. 23. · version:: cucwd 106 :: rev 1 2013 center for workforce...

CENTER FOR WORKFORCE DEVELOPMENT

Version :: CUCWD 106 :: Rev 1 2013

This material is based upon work supported by the National Science Foundation under Grant Number DUE-1104181. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

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Copyright © 2013 Clemson University Center for Workforce Development. All Rights Reserved.

* License information for illustrations and photographs can be found in the Attribution Table within the Open Text for each course module.

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CENTER FOR WORKFORCE DEVELOPMENT 7SAFETY

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7 Machinery, Hand Tool and Equipment Safety

» Explain the value of safe tool usage

» Identify potential mechanical hazards including nip points

» Describe the concepts related to hand-held power tool safety

» Compare and contrast the different types of safeguards used on industrial machinery

» Explain the importance of proper equipment maintenance and differentiate between pre-ventive and predictive maintenance

» List the steps required for appropriately using lockout and tagout procedures and defendthe need for each

OBJECTIVES

Why is it important to follow safety procedures?

What safety precautions should one take when working with industrial machinery?

How can mechanical hazards be identified and avoided?

Why is proper machine maintenance important?

How can machine repairs be done without putting the maintenance worker at risk?

The learner will be able to:

ORIENTING QUESTIONS

INTRODUCTIONNowadays, almost everyone has interacted with electrically powered tools or machines in their daily lives. Everything from the toaster you used to make breakfast to an electric pencil sharpener is a powered machine that must be used appropriately.

In this module we will discuss various industrial machines and tools, dangers associated with the inappropriate use of these tools and safety measures that should be followed while using these tools. We will also discuss the importance of preventive maintenance that could increase the life and safety of the machines, and the best ways to safely repair the equipment.

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7.1.0 Mechanical HazardsAnyone who has a job in the manufacturing industry may be exposed to different types of potential hazards. In this section we will discuss mechanical hazards, which include any situations in which a worker could be injured through interaction with a machine. Industrial machines typically cannot differentiate between a block of wood and a workers arm. Therefore, it is up to the operator to practice safe and proper usage of the equipment.

It is an employer’s responsibility to provide a safe work environment for all of their employees. Since almost all industrial work places have the potential for mechanical hazards, an employer must make sure that their employees can use this equipment without being injured. There are four main ways in which hazards can be dealt with:

1. Eliminate the hazard

2. Reduce the consequences of the hazard

3. Build safeguards around the hazard

4. Train employees to avoid the hazard

Often in industrial workplaces it is impossible to eliminate mechanical hazards completely because the equipment is required for production. It is also very difficult to reduce the consequences of the mechanical hazards because the machines have to function with the appropriate force in order to complete their job. So for many industrial workplaces, the feasible way to reduce mechanical hazards is to safeguard the machines and train their employees on the proper way to use the equipment. As an employee, you should make sure that you have received proper safety training before using any mechanical equipment.

Production technicians should practice safe tool by inspecting tools prior to use and proceeding properly when the inspected tool is unsafe for use. If you have any concerns about safety conditions in your workplace, discuss them with your supervisor. Under the Occupational Safety and Health Act, every employee has the right to have a safe work environment. The Occupational Safety and Health Administration (OSHA) is an organization that provides training and safety standards for industrial workplaces. If there are continuous concerns in your workplace about safety, contact OSHA for a safety inspection.

7.1.1 SAFEGUARDING THE POINT OF OPERATION

Building safeguards around a machine is one of the approaches used in industrial settings to reduce the likelihood of mechanical hazards. Safeguards are any barriers or restraints that physically keep an operator from injuring themselves on a machine. Safeguards can be applied to any part of the machine in use, but they are most effective when located around the point of operation. The point of operation of a machine is the area where work is being done. For example the blade of a saw, the part that cuts through the wood, would be the point of operation for the saw.



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When building a safeguard for a machine there are certain standards that one should follow. OSHA has created a list of requirements for all point of operation safeguards this list includes, but is not limited to the following:

» The safeguard must prevent the entry of hands and fingers in to the point of operation

» The safeguard must not create any hazardous areas between the guard and the machine

» The safeguard shall offer maximum visibility of the point of operation

Following these guidelines will help to create an appropriate point of operation safeguard that will help keep workers from getting injured.

7.1.1.1 Nip Points

Not all injuries are caused at the point of operation of a machine. Other injuries occur when a person’s hands or fingers get caught in other moving parts of the machine. Nip points are any points on a machine where a person’s body could get caught or injured between moving mechanical parts. The best way to prevent injury at nip points is to put a guard around them, but this is not always an option. As an employee the best way to avoid injury at nip points is to know how to recognize them and avoid putting your hands on or near them. Below is a list of some of the most common nip points and where they occur:

» Pinch point – Two mechanical parts moving to-wards each other that can crush or pinch objects

» Shear point – The edges of two parts move close together and have the potential tosever or cut objects

» Wrap point – Rotating mechanical parts in which hair or loose clothing can get caughtaround

» Pull-in point – Two parts, typically gears, near each other rotating in opposite directionscan pull in and crush objects that get caught between them

Activity 7.1.1.1» Match the machine description to the type of nip point it would create.

A. Pinch Point

B. Shear Point

C. Wrap Point

D. Pull-in Point

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1. The edges of a rotating wheel’s spokes brush past the sharp, metal edgeof the support bar.

2. A chain is connected to two rotating wheels as a guiding mechanism formoving trays.

3. Two cylinders rotate to feed plastic sheets through a mold

4. A clamp is used to hold the material down while work is done on it.



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Many people have used hand-held power tools in the course of their daily lives. Experiences like building birdhouses or installing shelves give people opportunities to become familiar with hand-held tools. But just because hand-held tools are commonly used does not mean that they are not dangerous. According to the Consumer Product Safety Commission, about 150,000 medical emergencies occur each year as a result of the mishandling hand tools. It is important that all tools be inspected before each use to ensure that the tool is working properly.

Hand-held power tools can be electric, hydraulic, pneumatic, and power-actuated. To prevent injuries, workers should wear appropriate protective equipment while operating these power tools, and only trained individuals should operate pneumatic and power-actuated tools. In this section we will discuss the hazards caused by working with hand-held tools and ways to avoid these hazards.

7.2.1 HAZARDS OF WORKING WITH HAND-HELD POWER TOOLS

Hand-held power tools are commonly owned and easily available to people. This familiarity with hand tools makes us perceive them as being less of a threat than they are. Hand-held power tools can cause injury just as easily as large industrial equipment can. In order to keep them safe, handheld tools must be cleaned and maintained regularly.

One of the reasons hand tools are so dangerous is because there is typically little or no guarding of the point of operation. If there is guarding, such as sheath, then it must be removed from the tool in order to use it. This lack of guarding makes it much easier for people to accidentally injure themselves while using the tool.

Another reason hand-held tools are dangerous is because they are not fixed to any tables or workstations, and if they are not wielded appropriately, they become a hazard. Before using any hand-held power tools, you must first learn the correct way to hold and use the tool so you do not put yourself and others in danger. Below are some examples of commonly used hand-held power tools and the hazards that could be caused by using them inappropriately.

Drills

Drills are tools used for cutting holes into wood and other materials. The main hazard in using drills is the potential for a person’s hand or other body part to come into contact with the drill bit, the cutting tool used to make the hole. The drill bit cannot be surrounded by a safeguard and still function properly, so the best way to avoid this hazard is train the worker on how to use a drill and to wear the appropriate hand and eye safety gear while using the tool.

7.2.0 Hand-Held Power Tool Safety



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The second potential hazard in using a hand-held power drill occurs when the user tries to hold piece of wood, stock, that they are trying to drill in their hand. This could cause two potential problems: one, they could drill through the wood into their hand, or two the wood could become stuck on the drill and spin, causing injury to the workers hand. The best way to avoid this hazard is to always use a clamping mechanism to hold the material down so it does not slip while being drilled.

Saws

Saws are tools used to cut through material by using a moving blade. There are three main hazards in using hand-held saws. One, the user could accidentally cut themselves. two, their loose fitting clothing or long hair could become caught in the saw and cause injury, or three, the user could accidentally cut through the saw’s electrical cord and create a shock hazard. All portable saws are required to have guards that cover up to the depth of the teeth of the blade, but many of these are removable or adjustable. Again if the user is not trained properly on the appropriate way to use a portable saw, they could injure themselves or others.

Sanders

Sanders are tools used for creating a finished surface on a material. They have a piece of abrasive sand paper that is wrapped around a motorized, rotating mount. One hazard of using a hand-held sander is that the worker could become injured if their body comes in contact with the sanding surface while it is running. Most sanders have two handles so that the user can put both hands on the tool leaving no hands available to be injured. Again worker’s clothing or hair could get caught in the rotating mount, which could cause injury. Many sanders have built in safeguards for this hazard, like a protective casing around the spinning mount. But as always with hand-held power tools, the best way to avoid injury is to be properly trained on the correct way to use the equipment safely.

Activity 7.2.1

» Think of the hand-held power tools that you have used in your lifetime. What are some ofthe safety precautions that you observed while using these tools? What additional precau-tions could you had taken in order to use the tool safely? If you use this tool again, howwould you use it differently?

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In industrial settings, one will encounter machines that are far more powerful, and therefore more dangerous, than hand-held equipment. These industrial machines are designed to cut, mold, melt, and move material quickly and efficiently. Performing these tasks quickly requires the machines to be able to produce a lot of force, or heat, and to work at a rapid pace. It is easy to be severely injured by this type of equipment because of the speed and force of their movements. Many types of safeguards have been built for these machines to ensure that the human body cannot get to the point of operation of the machines.

In this section we will discuss examples of electrical equipment, heat treatment equipment, and industrial robots to explain the potential hazards of each and ways to avoid these hazards.

7.3.1 ELECTRICALLY POWERED EQUIPMENT

Most of the equipment found in industrial or manufacturing settings, nowadays, is electrically powered. When working with machines capable of grinding, cutting, and bending material with large amounts of force, certain safety precautions must be taken. Safeguards are built around these machines to reduce the risk of injury, but the best way to avoid injury is to be knowledgeable about the machines and how to safely use them. The sections below contain information on three different commonly used electrical powered machines and some precautions to follow when working with them.

Power Presses

Mechanical power presses are machines used to shape metal through the use of dies. Dies are large-scale molds used in manufacturing settings to produce products of a certain shape and size. There are many different types of presses, some bend metal into a particular shape while others cut shapes out of material like a large cookie cutter. Refer to the image on the next page for an illustration of a power press using a die.

The main hazard associated with power presses is the potential for crushing or severing body parts placed in the point of operation while the machine is running. Barriers or guards are typically placed around the point of operation to avoid these injuries. If a worker is required to adjust the material while in the point of operation, appropriate tools should be provided so the worker does not have to place their hands in the machine. Also, OSHA requires that all new power presses have a presence sensing device installed in them. Presence sensing devices (PSDs) are any type of apparatus, such as a light sensor, that automatically stops the press from closing if it detects a worker’s limb in the point of operation.

Five Basic Rules for Machine Operation Safety

1. Observe a skilled operatorbefore using a machine

2. Make sure all machineguards are in place

3. Make all necessaryadjustments to the machinebefore starting

4. Do not operate a machinewith known problems

5. Be sure you know how toproperly shut down themachine

7.3.0 Industrial Machine Safety



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Some additional safeguards that are built into many power presses include two-hand controls and arm restraints. A two-hand control system requires a worker to have both of their hands on two different buttons in order for the press to close. Older power presses were foot-controlled, and this led to many accidents since the worker’s hands could be in the machine when it was engaged. Another safeguard that is commonly used for power presses is arm restraints. These are exactly what they sound like, restraints worn around the wrists that make it impossible for the worker to place their hands in the point of operation. These safeguards are both examples of interlocks. An interlock is a device that prevents a machine from running unless certain safety conditions are met. In these examples, the power press will only run when the user’s hands are out of the point of operation. Interlocks are effective safeguards if the worker uses them appropriately.

As a power press operator, you must always be aware of the point of operation and what surrounds it. If additional safeguards are to be used, like arm restraints, then make sure that they are being used appropriately. Also make sure you are aware of the machine’s potential nip points and any other hazards that the equipment may produce.

Grinding Machines

Grinding Machines are used to remove material from an object through the use of an abrasive rotating wheel. These machines are typically used to create desired finishes on metal objects. The main hazards associated with grinding machines involve excess material flying through the air or the abrasive wheel shattering while in use. Since the wheel rotates at high speeds, it must be guarded to avoid flying debris. According to the American National Standards Institute (ANSI) standard, only a quarter of the wheel’s surface is allowed to be unguarded.

The best way to avoid injury while using a grinding wheel is to wear the appropriate eye, face, and hand protection to cover your body and protect it from flying material. Another safety precaution to be observed is to inspect each grinding wheel before it is used. If a wheel cracked while in use, the high rotating speed would expel it and potentially cause a serious injury. To know whether or not a grinding wheel is safe to use, complete the “Ring Tap Test.” Tap the wheel with a non-metallic instrument and if it creates a clear ringing noise then it is safe to use, but if it sounds dull or muffled then the wheel could be damaged and unsafe for use. By completing this simple test and wearing the appropriate safety equipment, you can greatly reduce your risk of injury while using a grinding wheel.



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Band Saws

Band saws are a specific type of saw that use a thin, serrated strip of steel to cut through wood, metal or even meat. Band saws, unlike the hand-held saws discussed previously, are secured to a table and the material is fed through it manually. Naturally, the biggest hazard of using a band saw is the potential for limbs or hands to be cut or amputated. When using a band saw, keep your fingers at least 3 inches away from the blade. If you are cutting a small object and cannot safely hold the object and feed it through the saw, then use a push stick to guide the stock through the saw.

All band saws have an adjustable safeguard that covers the blade. Before using the saw, you should measure the width of the object to be cut and adjust the guard around the blade so that only enough of the blade is shown to cut through the stock. Since the entire blade cannot be guarded while in use, be sure to be aware of your hands and fingers and other objects in your work area. Also, always wear the appropriate eye and hand protection while using the saw to avoid injury from flying debris.

7.3.2 HEAT TREATMENT PROCESSES

In certain industrial settings, heat treatment processes are used to alter the physical properties of metal products. Heat treatment is the controlled heating and cooling of a metal object in order to soften or harden the material for a desired outcome. Heat processes can also be used for the molding or shaping of glass. Heat treatment processes are completed in industrial ovens or furnaces. The main hazards associated with ovens and furnaces are the potential for fire, and the exposure to high heat. When using an industrial oven, one must always wear a face shield and heat resistant protective clothing and gloves.

Some specific heat treatment processes, such as the hardening of steel, require the use of a quench. A quench is a liquid used to quickly cool a metal object after being heated in an industrial furnace. The process of quenching adds additional safety hazards such as exposure to quenching chemicals and potential for fires.



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7.3.3 INDUSTRIAL ROBOTS

Some manufacturing facilities, like car production lines, have tasks that need to be completed over and over again with speed and precision that may be hazardous for humans to endure. In these types of situations industrial robots are used. Industrial robots are automated and programmable machines, typically in manufacturing facilities that are used to manipulate materials in a variety of ways. Industrial robots can do everything from assembling objects and welding, to product testing. These fast paced workers are reliable and can endure environments that would be unsafe for humans.

Just like humans, these machines have a working envelope, which is the area around the robot in which it can physically reach and work on objects. For industrial robots, this working envelope is the point of operation for the machine. Unlike previously discussed machines, industrial robots have a very large point of operation and therefore have a large danger zone. The main hazard of industrial robots is that a worker could be in the robot’s working envelope and get injured by the movement of the machine. There are two main ways to safeguard against this type of hazard, either through the use of physical safeguards, or through the use of software programming safeguards.

Physical Safeguards

Except for during maintenance, workers should not be in a robot’s work envelope. A robot’s actions may seem familiar, predictable and easy to work around, but they have fast and powerful movements that could cause injury to a worker if they were close enough to get hit by the machine. In order to discourage workers from coming too close to the machines, physical safeguards like ropes, chains or fixed barriers can be placed around the perimeter of the work envelope. Physical safeguards, though helpful in making workers aware of a robot’s working envelope cannot always protect workers from harm, since a worker could easily climb over a rope or chain barrier. It is up the each individual worker to understand the hazards of coming too close to an industrial robot, and therefore respect the physical safeguard.

Software Programming Safeguards

Since physical safeguards are not always effective at protecting workers, industrial robots also have programmed safeguards in their software. These safeguards include presence sensing devices that automatically turn the robot off if a human is detected in a dangerous area, and software that makes it so the machine does not turn on or off suddenly without reason. Software programming safeguards are extremely important when the robot is undergoing maintenance.



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These safeguards are designed to keep workers safe while they work on or near the industrial robots. But as always the best way to be safe around robots is to give them their space and do not enter the robot’s working envelope. All personnel who must enter the working envelope in order to do maintenance should be properly trained on how to appropriately shut down the machine and work on it safely. Section 7.4 discusses the importance of machine maintenance and safety precautions to follow while working on a machine.

Activity 7.3.3» Imagine your company has just purchased a new band saw, but they are worried about

the potential injuries it may cause. Your boss asks you to design some new safeguards toprotect users from cutting themselves on the band saw. Sketch pictures of your ideas andexplain how your new safeguards would prevent injury but still allow the operator to use themachine appropriately.

Whenever you work with machinery there will be parts of the machine that get old, damaged, or break. When this happens, it may make the machine unsafe to operate. If these problems are not observed and fixed in a timely manner, then they could become a safety hazard. This is why it is important to properly maintain your work equipment.

7.4.1 PREVENTIVE AND PREDICTIVE MAINTENANCE

If a machine part breaks, causing the machine to be unusable, it may take a long time to get a new part and replace the broken one. During the time when the machine is broken down, no production can occur. There are two main types of maintenance that can help keep your ma-chines from breaking down, preventive maintenance and predictive maintenance. Preventive maintenance (PM) is the routine care and inspection of machines to find and correct problems before they cause the machine to fail. PM can include testing the machine’s functionality, making adjustments to the machine, or replacing partially damaged elements. PM is typically done when the equipment is turned off and not operating. Predictive maintenance (PDM) is condition-based care of machines to correct problems before they cause a machine to fail. For this type of maintenance, the performance of a machine is constantly monitored to know when maintenance is needed. PDM is conducted when a worker observes a need for repairs and is typically done while the machine is still running.

To further illustrate the difference between PM and PDM, we will use the example of a light bulb in your house. You know the light bulb is supposed to work for two years. If you change the light bulb after it has been used for two years, regardless of if it is burned out or not, then you have done preventive maintenance. If you constantly

7.4.0 Equipment Maintenance



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observe the light bulb and wait until the light bulb starts to flicker before you change it, then you have done predictive maintenance.

Some companies may have an “if it’s not broken don’t fix it” mentality, but preventive maintenance truly saves everyone time, money, and saves workers from potential injuries. PM should be done on a routine basis in order to keep all of your machines running properly. An equipment maintenance plan should be developed to manage how often each machine will be checked and what parts of the machine should be inspected.

Some companies use a maintenance method called total productive maintenance (TPM) which incorporates both preventive maintenance and predictive maintenance. The goal of total productive maintenance is to keep all of a facility’s machines in good condition without stopping the facility’s production. TPM works best if all of the individual machine operators are trained in the basic maintenance of the machine they use. This requires cooperation between machine operators and maintenance personnel. The operators can complete small maintenance problems without interfering with the machine’s production. This keeps the machines in good condition and utilizes the maintenance workers’ time.

Monitoring Equipment for Safety Hazards

Everyone has a role to play in preventive and predictive maintenance. As the operator of a machine, you are typically the person who is most familiar with the workings of that particular machine. Every day, before you use your machine, you should check the point of operation parts and the machine guarding to make sure it is all in good working condition. You should know what the machine looks like when it is working properly, and let your supervisor know if you see any problems or changes in the equipment. By being aware of your equipment you can prevent safety hazards from occurring.

7.4.2 EQUIPMENT REPAIR

It is impossible to prevent a machine from ever breaking down, and when it does it must be repaired as soon as possible. Though maintenance work is done to keep machine operators safe from harm, the act of repairing a machine can put the maintenance worker at risk. The damaged machine may expose the maintenance worker to hazardous materials, dangerous work conditions or other risks. Each maintenance worker should be properly informed as to the nature of the problem and be prepared for unexpected circumstances. Maintenance workers should be trained on different types of machine failures and the safest way to fix the equipment without endangering themselves. Section 7.5 discusses the shutdown procedures for equipment to be repaired and the hazards involved in completing maintenance on powered equipment.



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Assessment 7.4.1

» What is the difference between preventive maintenance and predictive maintenance?Compare and contrast these ideas. Give examples of these maintenance methods beingused outside of an industrial setting.

Preventive Maintenance Predictive Maintenance

Differences: Differences:

Similarities:

Examples: Examples:

Often times, maintenance crews are asked to repair parts on powered equipment. Even if the equipment is turned off, there is a chance that the power could accidentally be turned back on, or that the machine may suddenly release stored energy. Either of these scenarios can lead to serious injury if the maintenance person is in the machine’s danger zone.

In order to prevent this type of accident from occurring during maintenance, the machine to be repaired must be locked out, tagged out, and all hazardous energy must be released. Hazardous energy is any energy contained in a machine that could build up and suddenly release, causing the machine to move and potentially harm a nearby worker. OSHA’s Hazardous Energy Control Standard requires that employers provide training and periodic safety inspections, and have a procedure in place to isolate a machine from its energy source while being repaired. In this section we will discuss the concepts of lockout and tagout and how they are used to control hazardous energy.

7.5.1 LOCKOUT AND TAGOUT

When a maintenance worker is working on a machine, it is important that the machine is turned off and that it cannot be accidentally turned back on. One method of ensuring that a machine is not energized while being repaired is to use lockout and tagout procedures. The lockout procedure is the process of turning off the machine’s energy source, isolating the machine from the source using an energy-isolating device, and physically locking it so it cannot be accidentally turned back on. The tagout procedure is the process of labeling the power source with a tag that says not to turn the machine on.

Lockouts and tagouts can be used independently, but are most effective when used together to physically lock out and visually tag out the hazardous energy source. The person who is in charge of the lockout and tagout procedures should be the same person to remove the

7.5.0 Equipment Lockout Procedures and HazardousEnergy



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safeguard and turn the machine on when the maintenance is complete. Safety procedures associated with lockout and tagout are designed to keep the equipment from starting-up without warning, prevent the accidental release of energy, and protect against injury or death associated the energized equipment.

7.5.2 TRAINING FOR HAZARDOUS ENERGY CONTROL

Even if a machine is turned off and removed from its power source, it can still have hazardous energy stored within. To make sure that a machine has no stored hazardous energy you must release or discharge any potential energy built up in the machine. An example of this could be stopping rotating parts, venting the pressure on any pressurized fluids, or releasing the tension built up in springs. Employers should provide all employees with training that focuses on hazards associated with energy sources, energy types and magnitudes present in the workplace, and procedures that should be followed to isolate and control energy. Additionally, OSHA requires that companies develop a plan for energy control through lockout, and train their employees on this procedure. By releasing hazardous energy, you can create a safer environment for maintenance workers to operate in.

7.5.3 COMBINING LOCKOUT, TAGOUT AND ENERGY CONTROL

To create the safest possible environment for a maintenance worker, you should use the methods of lockout, tagout and hazardous energy control all together. Here are the steps to complete this process safely:

1. Identify the energy source(s) of the machine

2. Turn the machine’s energy source(s) off

3. Remove any potential energy stored in the machine through hazardous energy controlmethods

4. Isolate the machine from its energy source using an energy-isolating device

5. Lockout the energy-isolating device to keep the machine from being energized

6. Tagout the energy-isolating device to notify workers of the state of the machine

Once these steps have been completed it is safe to begin maintenance on the machine. After the machine is repaired, the same person who applied the lockout and tagout, and only that person, should remove them and energize the machine so it can be used for normal production again. If multiple people are working on one piece of equipment together, each person should install and remove their own lockout device to ensure that all of the workers are safe before the machine is restarted.

Assessment 7.5.3» A co-worker chooses to lockout a machine for maintenance but does not complete the

tagout procedure. Defend why it is important to use both lockout and tagout procedurestogether. Explain your answer.

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Key Concepts

» Mechanical hazards can be at the point of operation of a machine, or they can be nippoints elsewhere on the machine. A machine operator should understand the machine’spotential mechanical hazards and how to safety use the machine to avoid them.

» Hand-held power tools can create safety hazards. Using tools in a safe and appropriatemanner can help you avoid injury.

» Safeguards are designed to keep a worker form injuring themselves on a piece of danger-ous equipment, especially around the point of operation.

» Preventive and predictive maintenance can be used to keep industrial machines in goodworking order and avoid creating mechanical safety hazards.

» Lockout and tagout procedures are important to keeping maintenance workers safe whilethey repair mechanical equipment. Lockout and tag out can be used independently tohelp ensure safety during repairs, but they are more effective when used together.

Key Terms

The Occupational Safety and Health Administration has standards and safety requirements for most industrial machines. For more information on industrial safety and safety standards, use the internet and go to www.osha.gov.

Key TermsKey Terms

Further Study

7.1 Mechanical hazards pg.2

OSHA pg.2

Safeguards pg.2

Point of operation pg.2

Nip points pg.3

Pinch point pg.3

Shear point pg.3

Wrap point pg.3

Pull-in point pg.3

7.2 Drill pg.4

Drill bit pg.4

Stock pg.5

Saws pg.5

Sanders pg.5

7.3 Power presses pg.6

Dies pg.6

Presence sensing device pg.6

Interlock pg.7

Grinding machine pg.7

ANSI pg.7

Ring Tap Test pg.7

Band saw pg.8

Push stick pg.8

Heat treatment pg.8

Quench pg.8

Industrial robots pg.9

Working envelope pg.9

7.4 Preventive maintenance pg.10

Predictive maintenance pg.10

Equipment maintenance plan pg.11

Total productive maintenance pg.11

7.5 Hazardous energy pg.12

Lockout pg.12

Energy-isolating device pg.12

Tagout pg.12

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http://www.osha.gov



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» ANSI: American National Standards Institute

» Band saw: Specific type of saw that uses a thin, serrated strip of steel to cut throughmaterials

» Dies: Large scale molds used in manufacturing setting to produce products of a certainshape and size

» Drill: Tool used for cutting holes into wood and other materials

» Drill bit: The cutting tool on a drill used to make the hole

» Energy-isolating device: A device that prevents the diffusion of energy from a source to amachine, such as a circuit breaker

» Equipment maintenance plan: A plan that assigns how often each machine will havepreventive maintenance and what parts of the machine should be inspected

» Grinding machines: Machines used to remove material from an object through the use ofan abrasive rotating wheel

» Hazardous energy: Any energy contained in a machine that could build up and suddenlyrelease, causing the machine to move and potentially harm a nearby worker

» Heat treatment: The controlled heating and cooling of a metal object in order to soften orharden the material for a desired outcome

» Industrial robots: Automated, programmable machines that are used to manipulatematerials in a variety of ways

» Interlock: Safeguard that prevents a machine from running unless certain safetyconditions are met

» Lockout: The process of turning off a machine’s energy source, isolating the machinefrom the source using an energy-isolating device, and physically locking it so it cannot beaccidentally turned back on

» Mechanical Hazards: Any situations in which a worker could be injured throughinteraction with a machine

» Nip points: Any points on a machine where a person’s body could get caught or injuredbetween moving mechanical parts

» OSHA: Occupational Safety and Health Administration

» Pinch point: Nip point where two mechanical parts moving towards each other that cancrush or pinch objects

» Point of operation: The area of a machine where work is being done

» Power press: Machine used to form or shape metal through the use of dies

» Predictive maintenance: The condition-based care of machines to correct problems beforethey cause a machine to fail

» Presence Sensing Device (PSD): Any type of sensor that automatically stops a machine ifit detects a worker’s limb in the point of operation



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This material is based upon work supported by the National Science Foundation under Grant Number DUE-1104181. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

Copyright © 2013 Clemson University Center for Workforce Development. All Rights Reserved.

» Preventive maintenance: The routine care and inspection of machines to find and correct problems before they cause the machine to fail

» Pull-in point: Nip point where two parts, typically gears, near each other rotating in opposite directions can pull in and crush objects that get caught between them

» Push stick: Long stick used to guide stock through a cutting machine if it is unsafe to guide the stock with one’s hands

» Quench: A liquid used to quickly cool a metal object after being heated in an industrial furnace

» Ring tap test: Testing process used on grinding wheels to determine if a wheel is damaged or not

» Safeguards: Barriers or restraints that physically keep an operator from injuring themselves on a machine

» Sander: Tool used for creating a finished surface on a material

» Saw: Tool used to cut through material using a moving blade

» Shear point: Nip point where the edges of two parts move close together and have the potential to sever or cut objects

» Stock: Any material to be cut, drilled, or carved by a machine or tool

» Tagout: The process of labeling a power source with written instructions to not turn the power back on

» Total productive maintenance: A maintenance strategy that incorporates both predictive and preventive maintenance, requires cooperation between maintenance specialists and machine operators

» Working envelope: The area around a robot, or human, in which it can physically reach and work on objects

» Wrap point: Nip point where rotating mechanical parts can catch loose clothing or long hair and wrap it around the parts

16



7SAFETY

17

Attribution Tables

OPEN TEXT, ASSESSMENT GUIDE & POWERPOINT Author(s) Title Source License

Microsoft Clipart Hand toolhttp://office.microsoft.com/en-us/

images/results.aspx?qu=factory&ex=1#ai:MP900400417|mt:2|

With permission from Microsoft

Microsoft Clipart Blenderhttp://office.microsoft.com/en-us/

images/results.aspx?qu=blender&ex=1#ai:MP900402350|mt:2|


Microsoft Clipart Sawhttp://office.microsoft.com/en-us/images/results.aspx?qu=saw&ex=1

#ai:MP900387036|mt:2|


Microsoft Clipart Toaster http://officeimg.vo.msecnd.net/en-us/images/MH900424403.jpg


Microsoft Clipart Pencil sharpenerhttp://office.microsoft.com/en-us/

images/results.aspx?qu=pencil+sharpener&ex=1#ai:MP900385262|


Renevanderpeet at nl.wikipedia

Industrial machinery

http://commons.wikimedia.org/wiki/File:Workmaster.jpg CC-BY-SA-3.0

U.S. Navy photo by Mass Communication

Specialist Seaman Adam

York

Band saw

http://commons.wikimedia.org/wiki/File:US_Navy_061120-N-

1332Y-103_Aviation_Structural_Mechanic_Airman_Cesar_Schira,_

from_New_York_City,_uses_a_band_saw_to_fabricate_a_shelf_

in_the_airframes_shop_on_board_USS_Kitty_Hawk_(CV_63).jpg

Public Domain

Microsoft Clipart Power drillhttp://office.microsoft.com/en-us/

images/results.aspx?qu=drill&ex=1#ai:MP900401161|mt:2|


Microsoft Clipart Sawhttp://office.microsoft.com/en-us/images/results.aspx?qu=saw&ex=1

#ai:MP900177981|mt:2|


Microsoft Clipart sanderhttp://office.microsoft.com/en-us/

images/results.aspx?qu=sander&ex=1#ai:MP900177983|mt:2|


URMELPress Break Schematic

http://commons.wikimedia.org/wiki/File:Press_brake_schematic.svg CC- BY-SA 3.0

Glenn McKechnie

Tool and Cutter Grinder

http://commons.wikimedia.org/wiki/File:ToolandCutterGrinder-Panto-

graph-Dbit.jpgCC-BY-SA 2.5

http://commons.wikimedia.org/wiki/File:Press_brake_schematic.svg

http://commons.wikimedia.org/wiki/File:Press_brake_schematic.svg

http://commons.wikimedia.org/wiki/File:ToolandCutterGrinder-Pantograph-Dbit.jpg





7SAFETY

18

Attribution Tables

Fabiosix Band Saw http://commons.wikimedia.org/wiki/File:Band_saw.jpg Public domain

IchudovHeat Treating

Furnacehttp://commons.wikimedia.org/wiki/

File:Heat-Treating-Furnace.jpg CC- BY-SA 3.0

MixabestKUKA Industrial

Robots

http://commons.wikimedia.org/wiki/File:KUKA_Industrial_Ro-

bots_IR.jpgCC- BY-SA 3.0

Microsoft ClipartSoftware download

http://office.microsoft.com/en-us/images/results.aspx?qu=softw3are&

ex=2#ai:MP900390548|


Pedroantonio.ramirez

Monitoring equipment

http://commons.wikimedia.org/wiki/File:Ensayos_EN50550.jpg CC-BY-SA-3.0

U.S. Navy photo by

Photographer's Mate 3rd Class Clarck Desire

Equipment repair

http://commons.wikimedia.org/wiki/File:US_Navy_051003-

N-1126D-001_Aviation_Electronics_Technician_Airman_Jose_Vasquez_repairs_a_power_

supply_at_Aviation_Intermediate_Maintenance_Department_(AIMD)_

on_board_Naval_Air_Station_Jacksonville.jpg

Public Domain

U.S. Navy photo by Mass Com-

munication Spe-cialist 3rd Class Kenneth Abbate

Machine tool safety

http://commons.wikimedia.org/wiki/File:US_Navy_111025-N-OY799-174_Machinery_Repairman_Fireman_Dane_

McDonald,_from_Milwaukee,_Wis.,_fabricates_a_tool_on_a_universal_milling_machine.jpg

Public Domain

Cherie A. Thurlby

Industrial Machinery

http://commons.wikimedia.org/wiki/File:Defense.gov_photo_

essay_080118-D-7203T-043.jpg Chewrie A thurlby public domain

Public Domain

Microsoft Clipart Medicalhttp://office.microsoft.com/en-us/

images/results.aspx?qu=medical&ex=2#ai:MP900400871|mt:2|


http://commons.wikimedia.org/wiki/File:Band_saw.jpg

http://commons.wikimedia.org/wiki/File:Band_saw.jpg

http://commons.wikimedia.org/wiki/File:Heat-Treating-Furnace.jpg

http://commons.wikimedia.org/wiki/File:Heat-Treating-Furnace.jpg

http://commons.wikimedia.org/wiki/File:KUKA_Industrial_Robots_IR.jpg



safety - vchs cte · 2019. 1. 23. · version:: cucwd 106 :: rev 1 2013 center for workforce...

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