Industrial safety aims to reduce, control and eliminate hazards through proper management. There are various types of industrial hazards including chemical, mechanical, physical, electrical and fire. Mechanical hazards stem from machinery and can cause injuries. Machines must be properly safeguarded to minimize risks. Boilers and pressure vessels require safety valves, water gauges and blowdown valves to operate safely under pressure. Electrical hazards can cause burns, shocks or electrocution and death. Proper identification, isolation and grounding of power sources helps protect workers. Fires are fueled by the fire triangle of oxygen, heat and fuel and different fire classes require appropriate extinguishers. Detection devices also help identify fires early.

1. INDUSTRIAL SAFETY
Ms. V.KANNAGI
Associate Professor/ECE
R.M.K. College of Engineering and Technology

2. UNIT I
INTRODUCTION
Evolution of modern safety concepts
Fire prevention
Mechanical hazards
Boilers and Pressure vessels
Electrical Exposure

3. Industrial Safety
Industrial safety is primarily a management activity which
is concerned with
 Reducing
 Controlling
 Eliminating hazards from the industries
or industrial units.
Management of
Events
Protection of
employees
By minimizing
hazards

4. Types of Industrial Hazards
Chemical hazards
Mechanical hazards
Physical hazards
Electrical hazards
Fire hazards

5. Mechanical Hazards
A mechanical hazard is any hazard involving a machine or
process.

6. Contd….
 Shear Point
 Crush Point
 Pull – in Point
 Burn Point
 Wrap Point
 Free wheeling parts
 Stored Energy
 Thrown Objects

7. Mechanical Hazards
 Mechanical hazards are those associated with power-
driven machines whether automated or manually
operated.
 In an industry, people interact with machines that are
designed to drill, cut, shear, punch, etc.
 If appropriate safeguards are not in place or if workers
fail to follow safety precautions, machines can cause
major human injuries.
 Also machines can cause damage to the property and
machines can also harm the environment.

8. Safeguarding from Mechanical
Hazards
Machine safeguarding is to minimize the risk of accidents
of machine operator contact.
The contact can be either
• A direct Contact with Moving part.
• Contact with chips, chemical and hot metal splashes, and
circular saw kickbacks.
• Caused by the direct result of a machine malfunction.

9. Types of Guards
 Fixed guards
 Interlocked guards
 Adjustable guards

10. Safeguard Requirements
• Be secure and durable.
 Safeguards should be attached so that they are secure.
• Protect against falling objects.
 Objects falling onto moving machine mechanisms increase the risk of
accidents, property damage and injury. It should be prevented.
• Create no interference.
 Safeguards can interfere with the progress of work if they are not
properly designed. So worker may be disable it due to work deadline.
• Allow safe maintenance.
 Safeguards should be designed to allow the more frequently performed
maintenance tasks

11. General Precautions
 Operators should be trained and supervised to ensure
that they dress properly for the job.
 Shortcuts that violate safety principles and practices
should be avoided.
 Other employees who work around machines but do not
operate them should be made aware of the emergency
procedures.

12. Boilers and Pressure
vessels

13. Boilers and Pressure vessels
• A pressure vessel is a closed container designed to hold
gases or liquids at a high pressure substantially different
from the ambient pressure without bursting.
• A boiler is a tank to hold a liquid (often water) so that it
can be boiled by a heat source.
• Boilers often have to withstand high pressure, in which
case they would also be considered a pressure vessel.

14. Pressure vessels
• Fired Pressure Vessel
External Heat Source
• Unfired pressure Vessel
 No external Source required

15. Safety valves
• Provide a measure of security for plant operators and
equipment from over pressure conditions.
• To relieve pressure.
• Located on the boiler steam drum
• Automatically open when the pressure of the inlet side
of the valve increases past the preset pressure.
• All boilers are required to have at least one safety valve

16. Safety valve
POP – Open Completely at a
specific pressure
BLOWDOWN – Remains open
until a specified pressure drop has
occurred

17. Gauge glass
• Allows the boiler operator to
see the water level in the boiler.
• named gauge cock valves
• secure the boiler water and
steam from the gauge glass.
• Another valve located in line
with the gauge glass is used to
blow the gauge glass down.

18. Water Column
• A hollow vessel having two
connections to the boiler.
• The top connection enters the
steam drum of the boiler
• Enters the shell or head at
least 2 inches below the
lowest permissible water
level.
• To steady the water level in
the gauge glass
• Equipped with high- and
low-water alarms that
sounds a whistle to warn the
operator.

19. Blowdown Valves
• Located on the water column and on the lowest
point of the water spaces of the boiler.
• Used to remove scale and other foreign matter
• To control concentration of dissolved and
suspended solids in boiler water.
• The surface blowdown is located at the
approximate water level so as to discharge
partial steam and water.
• The surface blowdown removes foaming on
the top of the water surface and any impurities
that are on the surface of the water.

20. Types of Boilers
 Water-tube boilers
products of combustion surround the tubes through which the
water flows.
 Straight tube boiler
 Bent tube boiler
 Fire-tube boilers
products of combustion pass through the tubes and the water
surrounds them.
 Scotch marine boiler
 vertical-tube boiler
 horizontal return tubular boiler
 firebox boiler.

21. Boiler Emergencies
 Low water
 High water
 Serious tube failure
 Flarebacks
 Minor tube failure
 Broken gauge glass

22. Safety Precautions
• Protection against toxic or explosive gases
• Ventilating fan
• Workers should not be inside the waterside of the boiler
when pressure is being applied to test a valve that has
not been under pressure.
• Workers should wear protective clothing when making
boiler water tests.
• External air leaks. Cracks, blisters, or other dangerous
conditions in joints, tubes, seams, or blowoff connections
• Deposits on their heating surfaces and for grease or
other foreign matter in the water.

23. Electrical Hazards

24. Electrical injuries
BE SAFE:
Burns
Electrocution
Shock
Arc flash/arc blast
Fire
Explosions

27. Electrical Hazards
Electrocution:
• Is fatal
• Meaning: to kill with electrical shock
• Results when a human is exposed to a
lethal amount of electrical energy

29. Electrical Hazards
Arc Flash
 Sudden release of electrical energy through air when
a high-voltage gap exists and there is a breakdown
between conductors
 Gives off thermal radiation (heat) and bright, intense
light that can cause burns
 Temperatures as high as 35,000°F
Arc Blast
high-voltage arcs can also produce considerable
pressure waves by rapidly heating the air and
creating a blast

30. Electrical Hazards
Fire:
• Most result from problems with "fixed
wiring”
• Problems with cords, plugs, receptacles, and
switches also cause electrical fires

31. Electrical Hazards
Explosions:
• Occur when electricity ignites explosive
mixture of material in the air
• Note:
o Electricity is source of these hazards
o All hazards are of equal importance

32. Examples of fatal accidents
• Case #1: Worker electrocuted when the ladder come in
contact with overhead power lines
• Case #2: Worker electrocuted when mast come in
contact with high voltage overhead lines
• Case #3: Worker changing energized ballast on light
fixture was electrocuted and fell to the concrete floor
while working from an 8' fiberglass stepladder.

35. Electrical Protection Methods
Power source identification:
• Mark all breakers accordingly for the circuits
they protect
• Mark all disconnect means accordingly for
the equipment they service
• Identify all voltages with proper labeling

36. Employer Requirements
Employer requirements to protect workers:
• Ensure overhead power line safety
• Isolate electrical parts
• Supply ground-fault circuit interrupters (GFCI)
protection
• Establish and implement an AEGCP
• Ensure power tools are maintained in a safe
condition

37. Employer Requirements
• Ensure proper guarding
• Provide training
• Enforce LOTO safety related work practices
• Ensure proper use of flexible cords and
power strips
• Ensure proper identification of power
sources

40. Fire Hazards
 Conditions that favor fire development or growth
 Fire hazards usually involve the mishandling of fuel or
heat
 Fire or combustion is a chemical reaction between
oxygen and a combustible fuel
 Source of ignition= Spark, flame and high temperature
are needed

41. Fire Triangle
• The triangle illustrates
the three elements a
fire needs to ignite:
heat, fuel, and an
oxygen
• The fire extinguishes
by removing any one
of the elements in the
fire triangle.

42. Source of Fire Hazards
Types of Fires
• Class A Fires
• Class B Fires
• Class C Fires
• Class D Fires
• Class K Fires

43. Class A Fires

44. Class B Fires

45. Class C Fires

46. Class D Fires

47. Fire Extinguisher

48. Types of Fire Extinguisher

50. Fire Detection Devices
Smoke detectors
 require a flow of air in
order to work well
Heat detectors
 detect fires where there
is no smoke activated
by the significant
increase of temperature
associated with fire
Flame detectors
 react to the movement
of flames.