Safety In Design

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Safety In Design
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ASME Code of Ethics-- The Fundamental Canons

• Engineers shall hold paramount the safety, health
  and welfare of the public in the performance of
  their professional duties.
• Engineers shall perform services only in the
  areas of their competence.

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ASME Code of Ethics-- The Fundamental Canons
(cont.)

• Engineers shall continue their professional
  development throughout their careers and shall
  provide opportunities for the professional and
  ethical development of those engineers under
  their supervision.
• Engineers shall act in professional matters for
  each employer or client as faithful agents or
  trustees, and shall avoid conflicts of interest
  or the appearance of conflicts of interest.

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ASME Code of Ethics-- The Fundamental Canons
(cont.)

• Engineers shall build their professional
  reputation on the merit of their services and
  shall not compete unfairly with others.
• Engineers shall associate only with reputable
  persons or organizations.

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ASME Code of Ethics-- The Fundamental Canons
(cont.)

• Engineers shall issue public statements only in
  an objective and truthful manner.
• Engineers shall consider environmental impact in
  the performance of their professional duties.
• Engineers shall consider sustainable development
  in the performance of their professional duties

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Safety in Design

• ASME Code of Ethics
• Engineers shall hold paramount the safety,
  health, and welfare of the public in the
  performance of their professional duties.
• Your primary ethical responsibility is to
  society!

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What is a Dangerous Product?

• The American Law Institute states
• The article sold must be dangerous to an
  extent beyond that which would be ordinarily
  contemplated by the ordinary consumer who
  purchases it, with the ordinary knowledge common
  to the community as to its characteristics.
• 
  (continued)

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What is a Dangerous Product?

• There are some products which, in the present
  state of human knowledge are quite incapable of
  being made safe for their intended and ordinary
  use. Such a product, properly prepared and
  accompanied by proper directions and warnings, is
  not defective, nor is it unreasonably dangerous.

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Defective Products

• A defective product may be dangerous
• There are two types of product defects
• Manufacturing defects
• Design defects

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Manufacturing Defects

• A manufacturing defect exists when a product
  leaves the factory in substandard condition
• It differs from the manufacturers intended
  result
• It differs from other identical units
• Product liability cases involving manufacturing
  defects are difficult to defend!

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Design Defects

• A design defect exists if a product is less safe
  than ordinary expectations
• Designing for safety involves cost/benefit
  analysis
• How grave is the potential danger?
• What is the probability of danger?
• Are safer designs technically feasible?
• Are safer designs economically feasible?
• Would a safer design impact functionality?

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Designing for Safety

• Safety is not merely a bi-product of good design!
  It must be addressed explicitly!
• All potential hazards must be anticipated and
  addressed in some manner
• Eliminate the hazard
• Guard against the hazard
• Warn against the hazard
• Hazards includes those encountered during
  manufacture, use (including misuse/abuse),
  service, or disposal of the product

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Some Types of Hazards

• Mechanical/Kinematic Hazards
• Pinch points (rollers, mating gears)
• Cutters (Shears, die cutters)
• Crushing (presses)
• Electrical Hazards
• Shocks
• Short circuits
• Energy Hazards Unwanted releases
• Compressed/stretched springs
• Compressed gas
• Raised weights
• Capacitors

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Some Types of Hazards

• Ergonomic Hazards
• Operator errors
• Malicious acts
• Repetitive motion/strain injuries
• Environmental Hazards
• Noise
• Vibration
• Chemical waste
• Exhaust
• Electromagnetic disturbances
• Temperatures

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Acceptably Safe Designs (from Standard
Handbook of Machine Design, McGraw Hill)

• At least two independent malfunctions/errors are
  required to cause an accident.
• Errors in assembly, installation, connection or
  operation of critical subsystems are positively
  prevented.
• Errors/malfunctions of one component are
  positively prevented from causing other failures
  (no cascading failures)
• 
  (contd)

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Acceptably Safe Designs (from Standard
Handbook of Machine Design, McGraw Hill)

• Operations which could lead to failures are
  limited or controlled (interlocks)
• Energy buildup is controlled
• A release of energy greater than expected will be
  safely withstood

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