Accident Prevention Manual

1

• Accident Prevention Manual
• for Business Industry
• Engineering Technology
• 13th edition
• National Safety Council

Compiled by Dr. S.D. Allen Iske, Associate
Professor University of Central Missouri
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CHAPTER 26

• AUTOMATED LINES, SYSTEMS, OR PROCESSES

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Automated Lines, Systems or Processes

• Automation reduces labor costs, speeds up
  production, and can result in fewer errors.
• Robots can work in environments hazardous to
  humans.
• Robots can move heavy loads and do repetitive
  tasks.
• Robots used in assembly, material handling, spray
  painting, and welding.
• All computer-controlled processes can be
  considered automation.
• Automation can resolve some safety hazards, but
  its incorporation can also present new safety
  challenges.

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Automated Lines, Systems or Processes (Cont.)

• Technicians can no longer understand the entire
  system.
• Systems are now too complex and can have
  unintended interactions.
• Safety gains can be cancelled out by increased
  speeds.
• Engineers try to prevent accidents by reducing
  human control.
• Failures in highly complex automated software
  programs responsible for controlling chemical
  reactions, inventories, maintenance activities,
  and schedules can be the root cause of serious
  accidents.

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Manufacturing Philosophy

• Many newer manufacturing philosophies deigned to
  enhance corporate competitiveness are only
  possible with the use of sophisticated automation
  run by computers.
• Failures or software errors in these systems can
  result in serious adverse consequence.

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Manufacturing Philosophy (Cont.)

• Process safety management is a term initially
  applied to OSHAs 29CFR1910.119.
• The standard only applies to processes which
  contain certain highly hazardous chemicals.
• This systems engineering approach to managing
  hazards contains many management practices that
  are easily adopted for use on other systems.

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Manufacturing Philosophies

• Up-Front Planning for Safety
• This philosophy requires management to include
  safety costs and design in all new equipment,
  construction, and installation.
• Design-in Safety
• Another up-front approach to automated safety.
  Requires that safety factors are a primary
  considerations during design process prior to
  purchase or modification of automated equipment.

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Manufacturing Philosophies (Cont.)

• Just-in-Time Methods
• This method relies on manufacturing with reduced
  inventories and computerized scheduling which
  increases flexibility and reduces cost.
• Computerized Maintenance Management
• Equipment maintenance is managed through
  automation. Computers schedule maintenance and
  track repairs. Improves safety through predictive
  maintenance.

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Hazard Identification and Controls

• Guidelines
• Careful identification of hazards during design,
  installation, and operation
• Use of interlocking principles and devices where
  possible
• Design that ensures maintenance issues can be
  addressed safely
• Strategies developed to control the environment
  where the processes occur

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Hazard Identification and Controls (Cont.)

• Types of hazards
• Hazards vary by industry.
• Inhalation hazardsdusts and chemicals
• Burn hazardshigh temperatures, acids, bases,
  steam
• Radiation hazardsmicrowaves, gamma radiation for
  sterilization
• Pinch hazardsmoving parts must be safeguarded
• Explosions

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Hazard Identification and Controls (Cont.)

• Boundaries between restricted and non-restricted
  areas
• Boundary that separates restricted work area from
  areas where workers can work safely
• Envelope, maximumarea of maximum volume space
  for all robot part movements
• Restricted envelopeportion of envelope to which
  robot is restricted by limiting devices
• Operating envelopeportion of restricted envelope
  actually used by robot performing programmed
  motions

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Hazard Identification and Controls (Cont.)

• Visual and mechanical warnings
• Warnings that alert workers to hazards
• Includes signs, barriers, flashing lights, rails,
  lines on floor, or equivalent
• Signs may need to be in several languages
  depending on the workforce.
• International symbols may be necessary.
• Workers need to be trained in the meaning of the
  various warning signs.
• Audible warnings

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Barriers and Interlocked Barriers

• Hazard controls
• Start and stop controls need to be accessible.
• Robotic controls must be out of restricted area.
• Awareness barriers are visual barriers that keep
  workers from reaching into hazards.
• Perimeter barriers limit entrance into restricted
  areas.
• Interlocks are safeguards in which the operation
  of one control automatically prevents another
  control from operating.

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Barriers and Interlock Barriers (Cont.)

• Maintenance and safety
• Maintenance and repair personnel must be trained
  in safety procedures, hazard identification,
  specific equipment, regulatory standards.
• Preventive maintenance helps supervisors
  anticipate downtimes in production.
• Predictive maintenancemonitors machines,
  predicts failures reducing catastrophes.
• Lockout/tagoutwritten procedures, protects
  workers from hazardous energy sources.
• Various diagnostic aids and procedures help solve
  maintenance problems.

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Automated Production

• Automated materials handling and transport
• Must be safeguarded because of pinch points and
  the potential for falling product
• Conveyors, belts and hoistscontinuous transport
  of material to workstations
• Automated guided vehicles (AGVs)vehicle path
  guided by electromagnetic wires, painted lines or
  chemical guides. Floors must be kept clean and
  dry and vehicle should have anti-collision device.

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Robotic Equipment

• Robotic Industries Association definition of
  robot is a reprogrammable multifunctional
  manipulator designed to move material, parts,
  tools, or specialized devices, through variable
  programmed motions for the performance of a
  variety of tasks.
• handling devices with manual control
• automated handling devices with cycles
• programmable, servo-controlled robots with
  continuous point-to-point trajectories
• robots capable of type C specifications, which
  also acquire information from the environment for
  intelligent motion.

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Robotic Equipment (Cont.)

• Robots have three major components
• Manipulatorrobotic arm (base through wrist)
  working in the operating envelope
• Power supplypneumatic, hydraulic or electric
• Control system
• Non-servo control point-to-point typepick and
  place material applications
• Servo-control point-to-point typeload and unload
  product
• Servo-control continuous typespray painting and
  finishing operations

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Hazards of Robotics

• Hazards within operating envelope
• Hazards exist within reach of a robots arm.
• Accidents occur when robots start or move
  unexpectedly, drop objects, or human error.
• Safeguarding robots3 categories
• Safety in the process of manufacturing,
  remanufacturing, and rebuilding robots
• Installation of robots
• Safeguarding of workers exposed to hazards
  associated with the use of robots

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Hazards of Robotics (Cont.)

• Safeguarding personnel
• Robot teacherguides robot through its motions
  which are memorized by a computer. This presents
  the greatest danger to workers.
• Robot operatormust be protected from robot
  movements in the restricted envelope.
• Maintenance/repair personnelmust use
  lockout/tagout procedures operations and any
  modifications of robotic tasks.

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Hazards of Robotics (Cont.)

• Computer-integrated controls
• Many robots are controlled by computer programs.
• Lack of standardization among manufacturers and
  varying human-system interfaces represents a
  safety challenge to safety managers.

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Chemical Processes

• Process safety information
• Chemical processes have many hazards such as
  inhalation and explosion hazards.
• Managers must detail hazard information through
  written safety policies, engineering and
  administrative controls, worker training, and
  PPE.
• One method is the facility Chemical Process
  Document (CPD). The CPD is a sort of cook book
  which has all of the safety parameters for the
  safe operation of a facility.

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Chemical Processes (Cont.)

• General information in a CPD
• assessment of hazards of materials
• toxicity information
• permissible exposure limits
• physical data
• thermal/chemical stability data
• reactivity data
• corrosivity data
• hazardous effects of inadvertently mixed chemicals

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Chemical Processes (Cont.)

• Design information in a CPD
• block flow diagrams or simplified process flow
  diagrams
• process chemistry
• maximum needed inventory
• acceptable upper and lower limits for items such
  as temperatures, pressures, flows, and
  compositions

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Chemical Processes (Cont.)

• Mechanical design information in a CPD
• piping and instrument diagrams, electrical area
  classifications, and relief systems
• design in ventilation system
• equipment and piping specifications and
  description of the shutdown and interlock systems
• design codes employed
• required or mandatory inspections and maintenance
  activities

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Chemical Processes (Cont.)

• Hazards and risk analysis
• Safety personnel must ask THREE Whats
• What can go wrong?
• What is the probability that something will go
  wrong?
• What would be the consequences if something does
  go wrong?

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Hazards/Risk Analysis

• Hazard identification methods
• hazard surveys
• process checklists
• hazard and operability studies (HAZOP)
• safety reviews
• formal
• informal

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Hazard/Risk Analysis (Cont.)

• Other methods
• what if? analysis
• failure mode, effects, and criticality analysis
  (FMECA)
• fault tree analysis (FTA)
• event tree analysis (ETA)
• human error analysis
• Timing
• begins early in the process and remains ongoing

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Chemical Processes and Elements of Process
Safety Management

• Risk assessment usually has four components
• What potentially catastrophic incidents could
  possibly occur?
• What is the downwind dispersion likely to be in
  the event of a toxic gas release?
• What would the impact be on the workplace and
  community?
• Can we quantify or conduct a probability analysis
  for incidence occurrence?

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Chemical Processes

• Pre-startup reviews
• All elements of a process safety management
  program should be in place and running before
  beginning the warm-up or startup phase of a
  facility operation.
• Reviews should be updated every 310 years.
• High substance hazard index value or large
  quantities of toxic, flammable, or explosive
  substances
• Proximity to a populous area or large work force.
• Severe operating conditions that can cause
  corrosion or explosion.

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Chemical Processes (Cont.)

• Operating procedure manual
• Manual that details rules and guidelines for safe
  operation of the facility
• position of the person responsible for each
  facility areas
• clear instructions for safe operations
• operating conditions and steps for initial
  start-up
• normal, temporary, and emergency operations
• normal shutdown
• start-up following a turnaround
• operating limits (safety considerations apply)
• descriptions of consequences of deviation
• steps to correct or avoid deviations
• safety systems and their functions
• occupational safety/health considerations

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Chemical Processes (Cont.)

• Management of change
• Changes in technology can impact the workplace
  and the work environment.
• Managers must analyze these changes and how they
  affect safety, operations, and processes.
• Additional training may be required.

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Auditing

• Audits pinpoint deficiencies in safety and
  processes caused by factors such as changes in
  personnel or priorities.
• Audits should be conducted every 35 years.
• Auditing of process safety management is a line
  responsibility.
• Outside and inside audits are important and
  beneficial.