Module 19: Machine Guarding

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1. Slide 1

   MODULE 19

   • Machine Guarding
2. Slide 2

   What hazards exist?

   • Crushed by or drawn into equipment
   • Struck by moving parts
   • Struck by failed components or particles
3. Slide 3

   Key parts of machines

   • 1. Point of operation: where work is performed on the material, such as cutting, shaping, boring, or forming of stock.
   • 2. Power Transmission Device: transmits energy to the part of the machine performing the work
   • Includes flywheels, pulleys, belts, connecting rods, couplings, cams, spindles, chains, cranks, and gears.
4. Slide 4

   Key parts of machines

   • 3. Operation Controls: Control mechanisms
   • 4. Other moving parts: can include reciprocating, rotating, and transverse moving parts, feed mechanisms, and auxiliary parts of the machine
5. Slide 5

   Hazards to be Guarded

   • Things to guard include
   • In-running nip points
   • Rotating equipment
   • Flying chips or sparks
   • Belts or gears
   • Parts that impact or shear
6. Slide 6

   Rotating Parts

   • Can grip hair or clothing
   • Can force the body into a dangerous position
   • Projecting pieces increase risk
7. Slide 7

   In-Running Nip Points

   • Between 2 rotating parts
   • Between rotating and tangential parts
   • Between rotating and fixed parts which shear, crush, or abrade
8. Slide 8

   Reciprocating Parts

   • Risk of being struck between stationary and moving part
9. Slide 9

   Transverse motion

   • Continuous straight line motion
   • Worker struck or caught in pinch or shear point
10. Slide 10

    Cutting action

    • Direct injury from cutting action
    • Flying chips or sparks
    • Saws, drills, lathes, mills
11. Slide 11

    Punching action

    • Ram stamps materials
    • Danger at point of operation
12. Slide 12

    Shearing action

    • Powered blade that shears materials
    • Hazard at point of operation
13. Slide 13

    Bending action

    • Power applied to a slide to stamp/shape materials
    • Hazard at point of operation
14. Slide 14

    Guarding Principles

    • Prevent contact between hazardous moving parts and body or clothing
    • Secure guard: not easily removed
    • Protect from objects falling into machinery
    • No new hazards: sharp/rough edges
    • No interference with job/comfort/speed
    • Allow safe lubrication: without removing guards if possible
15. Slide 15

    Guarding Methods

    • Location / distance
    • Guards
    • Fixed
    • Interlocked
    • Adjustable
    • Self-adjusting
16. Slide 16

    Guarding Methods

    • Devices
    • Presence sensing
    • Pullback
    • Restraint
    • Safety controls (tripwire cable, two-hand control, etc.)
    • Gates
17. Slide 17

    Guarding Methods

    • Feeding & ejection methods
    • Automatic and/or semi-automatic feed and ejection
    • Robots
    • Miscellaneous aids
    • Awareness barriers
    • Protective shields
    • Hand-feeding tools
18. Slide 18

    Fixed Guard

    • Barrier is a permanent part of machine
    • Preferable over other types
19. Slide 19

    Interlocked Guard

    • Stops motion when guard is opened or removed
    • Interlocked guard on revolving drum
20. Slide 20

    Adjustable Guard

    • Barrier may be adjusted for variable operations
    • What are the drawbacks?
    • Bandsaw blade adjustable guard
21. Slide 21

    Self-Adjusting Guard

    • Adjusts according to size/position of material
    • Circular table saw self-adjusting guard
22. Slide 22

    Pullback Device

    • Cables attached to operator’s hands or wrists
    • Removes hands from point of operation during danger period
    • What are the drawbacks?
23. Slide 23

    Restraint Device

    • Cables attached to fixed point and wrists or hands
    • Adjustable to let hands travel in predetermined area
    • May be accompanied by hand-feeding tools
24. Slide 24

    Safety Tripwire Cable

    • Device located around the perimeter of or near the danger area
    • Operator must be able to reach the cable to stop the machine
25. Slide 25

    Two-Hand Control

    • Requires constant pressure on both pads to activate the machine
    • Hands on controls at safe distance while machine is in dangerous cycle
26. Slide 26

    Gate

    • Must close fully to protect user before cycle will start
    • Gate Open
    • Gate Closed
27. Slide 27

    Safeguarding by Location/Distance

    • Location of hazardous parts that is inaccessible or not a hazard during normal operation
    • Must maintain safe distance
    • Training, warning, communication necessary
28. Slide 28

    Protective Shields

    • Protection from flying particles or splashing fluids
    • Do not protect completely from machine hazards
29. Slide 29

    What regulations apply?

    • 29 CFR 1910 Subpart O
    • 29 CFR 1910 Subpart P for hand and portable power tools
    • API RP 54 6.8 Machinery and Tools
30. Slide 30

    Machinery and Machine Guarding

    • 29 CFR 1910 SUBPART O
31. Slide 31

    Organization

    • 211.Definitions
    • 212.General requirements for all machines 213.Woodworking machinery requirements 215.Abrasive wheel machinery
    • 216.Mills and calenders in the rubber and plastics industries
    • 217.Mechanical power presses
    • 218.Forging machines
    • 219.Mechanical power-transmission apparatus
32. Slide 32

    29 CFR 1910.212

    • General Requirements
33. Slide 33

    1910.212(a) Machine guarding

    • 1. One or more types of guarding to protect from hazards.
    • Barrier guards
    • Two-hand tripping devices Electronic safety devices Etc.
    • 2. Affixed to machine where possible
    • Guard must not cause its own hazard
34. Slide 34

    1910.212(a) Machine guarding

    • Point of operation guarding:
    • ii.
    • Guarded if exposes employee to injury
    • iii.
    • iv.
    • According to standards or
    • Keep any part of body out of danger zone
    • Hand tools to permit material handling – in addition to guards, not instead Examples of machines requiring guards on point of operation
35. Slide 35

    1910.212(a) Machine guarding

    • 4. Revolving barrels, drums, containers guarded by interlocked enclosure (cannot turn without guard in place)
    • 5. Exposure to fan blades: guard openings ≤1/2 inch
36. Slide 36

    1910.212(b) Anchoring fixed machinery

    • Machines designed for fixed location must be anchored to prevent moving
    • This pedestal grinder is designed for anchoring, but is not anchored
37. Slide 37

    Abrasive Wheel Machinery

    • 29 CFR 1910.215
38. Slide 38

    1910.215(a) General requirements

    • Abrasive wheels must be guarded, with exceptions
    • Guard design dependent on type of work and type of wheel
39. Slide 39

    1910.215(a) General requirements

    • Work rests:
    • Rigid, clamped in place securely
    • Adjusted to within 1/8 inch of wheel
    • Never adjusted while in motion
    • Work rest is closely adjusted
40. Slide 40

    1910.215(b)(9) Exposure adjustment

    • For type where operator stands in front of opening: Adjustable for decreasing wheel size
    • Adjustable tongue guard must never be more than ¼ inch from wheel
41. Slide 41

    1910.215(d) Mounting

    • Inspect for damage and ring test immediately before mounting
    • Tap with light nonmetallic implement (screwdriver, wooden mallet)
    • If sound is dead, cracked ring may not be used
    • Check spindle speed against maximum for wheel
42. Slide 42

    Ring Test

43. Slide 43

    29 CFR 1910.219

    • Mechanical Power- Transmission Apparatus
44. Slide 44

    Organization of 1910.219

    • (a) General requirements
    • (b) Prime-mover guards
    • (1) Flywheels
    • (2) Cranks and connecting rods
    • (3) Tail rods or extension piston rods
    • (c) Shafting
    • (d) Pulleys
45. Slide 45

    Organization of 1910.219

    • (e) Belt, rope, and chain drives
    • (f) Gears, sprockets, and chains
    • (g) Guarding friction drives
    • (h) Keys, setscrews, and other projections
    • (i) Collars and couplings
    • (j) Bearings and facilities for oiling
    • (k) Guarding of clutches, cutoff couplings, and clutch pulleys
46. Slide 46

    Organization of 1910.219

    • (l) Belt shifters, clutches, shippers, poles, perches, and fasteners
    • (m) Standard guards-general requirements
    • (o) Approved materials
    • (p) Care of equipment
47. Slide 47

    Hazards on Oil and Gas Sites

    • Machine Guarding
48. Slide 48

    Parts Requiring Guarding

    • Drive belts and shafts – mud pumps and tank area
    • Pony rods
    • Rotating parts
    • Shale shaker
    • Agitator shafts & couplings
    • Moving generator parts
    • (explore)
49. Slide 49

    Mud Pumps

50. Slide 50

    Shale Shaker

51. Slide 51

    Generators

52. Slide 52

    Parts Requiring Guarding

    • Air compressors
    • Crown sheaves
    • Kelly bushing – or controls
    • Rotary chain drive
    • Air hoist line
    • Drawworks
    • Bench grinder wheels
53. Slide 53

    Crown Sheaves

54. Slide 54

    Kelly and Bushing

    • Alternative Abatement: STD 1-12.28 CH-1
55. Slide 55

    Drawworks

56. Slide 56

    Parts Requiring Guarding

    • Belts, drive chains, gears and drives on power and hand tools
    • Traveling blocks
    • Sheaves
    • Cathead?
57. Slide 57

    Drilling Line

58. Slide 58

    Traveling Block

59. Slide 59

    Hoisting Line

60. Slide 60

    Machine Guarding

    • Safety Responsibilities
61. Slide 61

    Safety Responsibilities

    • Management:
    • Ensure all machinery is properly guarded
    • Supervisors:
    • Train employees on specific guard rules in their areas
    • Ensure machine guards remain in place and are functional
    • Immediately correct machine guard deficiencies
    • Employees:
    • Do not remove guards unless machine is locked and tagged
    • Report machine guard problems to supervisors immediately
    • Do not operate equipment unless guards are in place
62. Slide 62

    Training

    • Operators/affected employees should receive training on:
    • Hazards associated with particular machines
    • How the safeguards provide protection and the hazards for which they are intended
    • How and why to use the safeguards
    • How and when safeguards can be removed and by whom
    • What to do if a safeguard is damaged, missing, or unable to provide adequate protection
63. Slide 63

    Hand and Portable Power Tools

    • 29 CFR 1910 Subpart P and 1926 Subpart I
64. Slide 64

    Construction vs. General Industry

    • Construction, alteration, or repair?
    • Applicable standard depends on type of operations:
    • 1910 Subpart P: Hand and Portable Powered Tools and Other Hand-Held Equipment
    • 1926 Subpart I: Tools – Hand and Power
65. Slide 65

    1910.242 General

    • Employer is responsible for safe condition of tools and equipment
    • Including equipment furnished by employee
    • Compressed air must not be used for cleaning unless:
    • Reduced to <30 p.s.i.
    • Only with effective chip guarding and PPE
66. Slide 66

    1910.243(a) Portable powered tools

    • Portable circular saws >2 in. guarded
    • Switches and controls:
    • Automatic return to covering position
    • constant pressure control for circular and chain saws other controls for other tools as appropriate
67. Slide 67

    1910.243(a) Portable powered tools

    • Portable belt sanding machine guarding
    • Nip points
    • Unused run of sanding belt
    • Cracked saws: remove from service
    • Grounding: Meet Subpart S
68. Slide 68

    1910.243(b) Pneumatic powered tools and hose

    • Tool retainer to prevent ejection
    • Airhose designed for applied pressure and service
69. Slide 69

    1910.243 Guarding of portable powered tools

    • c. Portable abrasive wheels:
    • Must be guarded
    • Ring test and inspection
    • d. Explosive actuated fastening tools
    • e. Power lawnmowers
    • Guarding
    • Controls and shutoff device Labeling, manuals
    • Design
70. Slide 70

    1910.244 Other portable tools and equipment

    • a. Jacks
    • Loading and marking Operation and maintenance
    • b. Abrasive blast cleaning nozzles: operating valve and support
71. Slide 71

    1926.300 General requirements

    • Maintained in safe condition whether furnished by employer or employee
    • Shall be guarded when designed to accommodate guards
    • Moving parts that create hazards shall be guarded by one or more methods
    • Fan openings; anchoring machinery
72. Slide 72

    1926.300 General requirements

    • Abrasive wheel guards
    • PPE if necessary for objects, particles, gases
    • Allowable switches by tool type
73. Slide 73

    1926.301 Hand tools

    • Use of unsafe hand tools not permitted
    • Wrenches shall not be used when jaws are sprung to the point of slippage
    • Including adjustable, pipe, end & socket wrenches
    • Impact tools shall be kept free of mushroomed heads
    • Such as drift pins, wedges & chisels
    • Wooden handles shall be kept
    • Free of splinters or cracks
    • Tight in the tool
74. Slide 74

    1926.302 Power-operated hand tools

    • Electric power-operated tools
    • Double-insulated or grounded
    • Never hold by the cord
    • Pneumatic power-operated tools
    • Secure tools, attachments, and muzzle
    • Compressed air use restrictions
    • Never hold by the hose
    • Reduce pressure in case of hose failure
75. Slide 75

    1926.302 Power-operated hand tools

    • Fuel operated tools
    • Stop while refueling or servicing
    • Watch concentrations in enclosed spaces
    • Hydraulic power tools
    • Fire-resistant fluids
    • Safe operating pressures
    • Powder-actuated tools
76. Slide 76

    1926 Subpart I Organization

    • 1926.303 Abrasive wheels and tools
    • 1926.304 Woodworking tools
    • 1926.305 Jacks
    • 1926.306 Air receivers
    • 1926.307 Mechanical power-transmission apparatus