Subpart%20J:%20Welding%20and%20Cutting

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Subpart J Welding and Cutting

• Doris Kemp
• BCT 480

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Welding

• Welding joins two pieces of metal by the use of
  heat and/or pressure
• Brazing or soldering involves a filler metal
  which has a lower melting point than the metal
  pieces to be joined
• Metal cutting is done by heating the metal with a
  flame and directing a stream of pure oxygen along
  the line to be cut

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Welding

• Arc Welding
• Shielded Metal Arc Welding (SMAW)
• Metal Inert Gas (MIG)
• Tungsten Inert Gas (TIG)
• Plaza Arc Welding (PAW)
• Submerged Arc Welding (SAW)
• And Many More..more than 80 in all

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Health HazardsGases Fumes

• Generally, gases and fumes come from
• Base material filler material
• Coatings paints
• Shielding gases chemical reactions
• Process consumables used
• Contaminants in the air

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Health HazardsGases Fumes

• Welding Smoke is a mixture of very fine
  particles called fumes and gases
• Welding Smoke contains fumes and gases
  including
• Chromium, nickel, arsenic, asbestos, manganese,
  silica, beryllium, cadmium, nitrogen oxides,
  phosgene, acrolein, fluorine compounds, carbon
  monoxide, cobalt, copper, lead, ozone, selenium,
  and zinc
• cancer causing agents include cadmium, nickel,
  beryllium, chromium, and arsenic

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Health Hazards

• Exposure to welding smoke may have
• Short-term effects
• Effects happen at or very soon after exposure
• Long-term effects
• Effects may happen after repeated overexposures
  or an extended time after the exposure

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Short-term exposures

• Welding smoke can
• irritate the eyes, nose, chest and respiratory
  tract
• cause coughing, wheezing, shortness of breath,
  bronchitis, pulmonary edema, and pneumonitis
• cause nausea, loss of appetite, vomiting, cramps,
  and slow digestion

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Long-term exposures

• Studies of have shown that welders have an
  increased risk of lung cancer and, possibly,
  cancer of the larynx and urinary tract
• Welders may experience a variety of chronic
  respiratory problems, including
• Bronchitis, asthma, pneumonia, emphysema,
  pneumoconiosis, decreased lung capacity,
  silicosis, and siderosis

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Long-term exposures

• Other health problems include
• Heart disease
• skin diseases
• hearing loss
• chronic gastritis
• ulcers of the stomach and small intestine
• other reproductive risks

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Other Health Hazards

• Heat exposure
• Heat stress,
• heat stroke
• Skin burns and skin cancer
• Noise
• Can result in stress, increased blood pressure,
  may contribute to heart disease, tiredness,
  nervousness, and irritability

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Other Health Risks

• Eye damage- More than 5 of all eye injuries in
  the construction industry are associated with
  welding, cutting, and brazing
• damage to retina
• damage to cornea, resulting in cataracts
• permanent eye damage
• Invisible UV light can cause arc eye or
  welders flash
• May include sandy or gritty eye, blurred vision,
  intense pain, tearing, burning and headache

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Engineering Controls and Work Practices

• Welding booths should be painted with dull
  finishes so they dont reflect UV light
• Acoustic shields between the worker and noise
  sources can reduce exposures
• Noisy machinery can be totally enclosed

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Engineering Controls and Work Practices

• Use cadmium-free silver solders
• Use asbestos- free electrodes, gloves, and hot
  pads
• Use work area barriers to protect others working
  in the same general area

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General Precautions

• Construction personnel that is welding should be
  properly trained and qualified
• Inspect work area for fire hazards before welding
• Make provisions for ventilation before welding
• Compressed gas cylinders should always be secured
  in an upright position when not in use and
  handled with extreme care

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General Precautions

• Gas cylinders should be stored at least 20 feet
  away from flammable materials and heat sources
• Oxygen cylinders should be stored at least 20
  feet away from gas cylinders and combustible
  materials.
• When not possible, use a 5 ft tall noncombustible
  barrier with a 30 min. fire-resistance rating or
  better

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General Precautions

• All combustible materials should be removed from
  welding area or covered with noncombustible
  material, prior to welding
• If covered, a worker that has experience using a
  fire extinguisher should be posted near as fire
  watch
• Workers should stand to the rear or side of
  regulators when opening valves on tanks
• Proper PPE should be worn, even by workers not
  welding

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Other Precautions

• Dont weld on painted surfaces
• Use water table to reduce noise
• Properly maintain equipment
• Proper housekeeping
• Use lowest possible amperage
• Hold electrode perpendicular and close to work
  surface
• Never weld or cut within 200 feet of degreasing
  equipment or solvents

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Personal Protective Equipment (PPE)

• PPE must be used in conjunction with engineering
  controls and safe work practices
• Use of one does not eliminate the need for the
  other
• Eye protection should be used in all welding
  operations
• Wear face shields or helmets and goggles or
  safety glasses
• Use appropriate filters on eye protection

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Protective Clothing

• Fire resistant gauntlet gloves
• Head cap
• High top hard toed shoes
• Leather apron
• Face shield
• Flame retardant clothing
• Safety Glasses
• Safety helmet
• Hearing plugs and/or muffs

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Electrical Hazards

• Even though welding generally uses low voltage,
  there is still a danger of electric shock
• Wet work areas, cramped work spaces
• Falls, fractures and other accidents can result
  from electrical exposure
• Even small shock can cause brain damage
• Death can occur from large shocks

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Electrical Precautions

• Always use dry gloves
• Always wear rubber soled shoes
• Always use insulating layers
• Protect yourself from surfaces that conduct
  electricity
• When working on electrically powered machinery,
  make sure the frame is grounded
• Keep insulation on all welding equipment and
  components dry and in good condition
• Dont change electrodes with bare hands, wet
  gloves or while standing on wet or ungrounded
  surfaces

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Fire and Explosion Precautions

• Never weld or cut on containers that have held a
  flammable or combustible material unless the
  container is thoroughly cleaned or filled with an
  inert gas
• A fire inspection should be performed prior to
  leaving a work area and for at least 30 minutes
  after the operation is completed
• Fire extinguishers should be nearby, of proper
  size, type and number for the hazards involved

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Dangerous Machinery

• All machines in the area with moving parts must
  be guarded to prevent workers contact
• e.g. hair, clothing, fingers
• When repairing machinery by brazing and welding,
  power must be disconnected, locked out, and
  tagged so the machinery cannot be started up
  accidentally

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Trips and Falls

• Keep work areas clear of equipment, machines,
  cables, and hoses
• Always properly maintain and use handrails
• Always use and maintain safety lines, harnesses
  and lanyards
• Always make sure that scaffolds are properly
  assembled and used

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Welding Hazards in Confined Space

• A work area with limited access, little or no
  airflow, not intended for continuous occupation
• May also have dangerous atmospheres, hazardous
  configurations, or other hazards
• All employees working in or around confined space
  must be trained
• Adequate ventilation must hold fumes and smoke to
  levels within the safe breathing range set forth
  in 29 CFR 1926 subpart D

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Welding Hazards in Confined Space

• No worker should work in an area with less than
  19.5 or more than 23.5 oxygen content
• Use continuous mechanical ventilation and proper
  respiratory protection
• When adequate ventilation cannot be achieved,
  workers must be provided with air supplying
  respirators as described in 29 CFR 1926 Subpart
  E

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Welding Hazards in Confined Space

• Always leave gas cylinders and welding power
  sources outside the confined space
• Only take hoses or welding leads into confined
  space and remove when leaving for breaks, shift
  or crew changes
• All pipes, ducts, and power lines that are not
  necessary for the work should be
  disconnected/locked out/tagged out

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Gas welding Precautions

• When transporting and handling, valve cap should
  be securely in place
• Cylinders should never be lifted by valve cap
• Cylinder valve should be closed when cylinder is
  empty, being moved or not in use
• Cylinders should be secured to a pallet, cradle,
  or sling board for hoisting
• Cylinders should not be dropped, bumped, struck
  or receive any other huge impact
• Cylinders should be thawed with warm water when
  frozen in place

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Gas welding Precautions

• Fuel, gas and oxygen hoses must be easily and
  clearly distinguishable.
• Oxygen and gas hoses must not be interchangeable
• When oxygen and fuel hoses are taped, no more
  than 4 inches per foot of hose may be taped
• Gas and oxygen hoses must be inspected before
  every shift and removed if defects are found.
• Torches should be inspected before each shift to
  detect leaks
• Tip openings should be kept clean and unclogged
• Torches should be lighted by friction lighters

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Arc welding Precautions

• Only use manual electrode holders designed
  specifically for arc welding
• All current-carrying parts should be properly
  insulated for maximum voltage encountered
• Cables must be properly insulated, flexible and
  able to handle maximum current required
• All equipment and cables should be inspected
  before each shift and should be removed if any
  defects are found
• Operations should be shielded appropriately as to
  protect other workers in the area

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Subject to damage from other activities in the
vicinity
Electrical cord in Contact with the cylinder
Cylinder laying in a horizontal position.
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Chain
Cylinders are not protected from falling.
Note that the Chain is not secured across.
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Electrical Cord

• 1. Cylinder not secured

2. Cylinder should be stored
3. Subject to damage.
4. Electrical cord draped over.
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1. Small cylinder not tied off
2. Combustibles stored with cylinders
3. Bad housekeeping
4. Acetylene and Oxygen stored too close together
and no chain.
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1. Cylinder with no valve or cap installed
2. Laying horizontal on the ground
3. Subject to damage
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Electrical arc damage
Cylinder is damaged. Should be taken out of
service immediately!
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Cylinder should be in storage protected from
damage and not laying on the ground regardless
if it is full or empty
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Old, corroded cylinder that should have been
disposed of a long time ago.
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Forklift
1. Cylinders laying on the ground and improperly
stored
2. Subject to damage from forklift operation in
vicinity
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1. Feed line exposed to damage/leak that could
cause a fire/explosion
2. Tripping Hazard
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1. Inadequate housekeeping
2. Valve caps should be installed.
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Acetylene Cylinder

1. Unsecured acetylene cylinder 2. Exposed to damage

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Unsecured cylinders
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Regulator left pressurized after use
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Improper Storage
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Tie Off?
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Improper storage of cylinders- acetylene and
oxygen stored next to each other
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Evidence of smoking next to acetylene cylinders
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This cylinder should be taken to storage and
housekeeping should be improved.
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Unsecured cylinder
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Unsecured Cylinder
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Cooking equipment within 20 ft of containers
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Tied
Not Tied
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oxy-acetylene torch connected To bottles without
the torch connected.
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Not in use. Should be Stored.
No cap installed
Housekeeping
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Cylinder not in use with regulators still On the
cylinder
Free standing cylinder
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Free standing cylinder
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Free standing cylinders
Chain
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Cylinder tied only With a bungee cord
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Cylinders not Secured properly
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Free standing cylinders
Exposed to damage From construction Activities in
area
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Free standing cylinders
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Cylinder laying on its side
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References

• Coll, R. (2002, October 17). Compressed Gas
  Cylinder Training Slides.
• Retrieved September 10, 2009 from , Web site 
    http//siri.uvm.edu/ppt/cgcsafety/sld001.htm
• Goetsch, D. (2010). Construction safety and the
  OSHA standards.    Boston Pearson.
• Saverio (2003). Welding Safety. Retrieved
  September 10, 2009    from , Web site   
  http//www.authorstream.com/Presentation/Saverio-
  42953- Welding-Safety-2003-Health-Hazards-HazardsG
  ases-Fumes-Short- term-Entertainment-ppt-powerpoin
  t/