Transcript Welding, Soldering, Brazing

Welding, Soldering, Brazing
Max Akhterov
Zettl Group Safety Talk
11/07/06
Welding
Welding is a materials joining process which produces coalescence of materials by heating
them to suitable temperatures with or without the application of pressure or by the application of
pressure alone, and with or without the use of filler material.
The American Welding Society
AWS distinguishes the welding processes according to:

Mode of energy transfer

Influence of capillary attraction in effecting distribution of filler metal in the joint
Groups of welding processes:
• Arc welding
• Brazing
• Oxyfuel Gas Welding
• Resistance Welding
• Solid State Welding
• Soldering
• Other
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Hazards
1. Fumes and Gases
2. Electric Shock
3. Radiation
4. Noise
5. Fire and Burns
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Fumes and Gases
Fumes are solid particles which originate from welding consumables, the base
metal, and any coatings present on the base metal.
Possible effects of over-exposure (magnesium, copper, zinc, lead, chromium, etc.):
•
Irritation of eyes, skin, respiratory system
•
Symptoms: nausea, headaches, dizziness, metal fume fever
•
manganese overexposure can affect the central nervous system
resulting in impaired speech and movement
•
In confined spaces the gases might displace breathing air and cause asphyxiation
How to avoid:
•
Do not breathe the fumes
•
Use respiratory protection
•
Use enough ventilation or exhaust
•
Be sure the breathing air is safe
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Electric Shock
The voltage used in welding: 120 – 575 V
The current used in welding: 150 – 500 A
Possible effects of electric shock:
•
Spasms
•
Burns
•
Muscle paralysis
•
Death
How to avoid:
• Properly install and ground the equipment
• Wear dry, hole-free, insulating gloves and
protective clothing
•
Insulate yourself from the work piece
and ground
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Radiation
Radiation is electromagnetic energy given off by the arc or flame that can injure eyes
and burn skin. Operator does not see ultraviolet and infrared radiation. Radiation is often
silent and undetected, yet injury occurs. Two type of radiation: Ionizing, Nonionizing.
Possible effects of radiation:
•
Skin burns
•
Eye damage
•
Skin cancer
•
Symptoms: “sand in the eyes”, feeling of pressure in the eyes, tearing, photophobia
How to avoid:
•
Use welding helmet with correct shade of filter plate
•
Protect skin with adequate gloves and clothing
•
Be aware of reflections from welding arcs
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Noise
In welding noise may result from the process, the power source, or other equipment.
Excessive noise is a known health hazard.
Possible effects of noise:
•
Loss of hearing that may be either full or partial and either
temporary or permanent
•
Hearing loss may be a temporary threshold shift from which
the ears may recover if removed from the noise source
How to avoid:
•
Shield the source where practical
•
Reduce the intensity of the source
•
Use earmuffs
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Fire and Burns
Welding processes produce molten metal, sparks, slag, and hot work surfaces. These can
cause fire or burns.
How to avoid fire:
•
Remove combustible materials for a minimum radius of 10.7 meters around the work area
•
Cover or block all openings, such as doorways, windows, cracks, or other openings with
fire resistant material
•
Do not weld on or cut material having a combustible coating or internal structure
How to avoid burns:
•
Wear dry, hole-free insulating gloves
•
Wear oil-free protective garments such as leather gloves, heavy shirt, cuffless pants,
high shoes, and a cap
•
Use approved helmets and safety goggles
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Personal Protective Equipment
Respiratory protection
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Personal Protective Equipment
Eye safety
Safety eyewear should always be worn
under the welding helmet to protect
against flying debris when the helmet is
raised to inspect work and when engaged
in other welding activities, e.g. grinding,
hammering.
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274 Le Conte Hall
Oxy-fuel welding and cutting safety
(flame temperature 2000 C):
• Before using an oxyhydrogen setup, ensure that
flammable materials such as grease, oil, paint,
sawdust, etc are cleared from the area
• Use enough ventilation or exhaust
• Shaded goggles with enclosed sides to protect
your eyes from glare sparks and splatter
• Wear leather gloves to protect your hands from
burns. Clothes and shoes/boots appropriate for
welding.
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Soldering
Soldering safety (about 400°C):
• Work only in well-ventilate areas
• Use soldering support
• Avoid touching the mains flex
with the tip of the iron
• Always return the soldering iron to
its stand when not in use
• Wash your hands after using
solder
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Resources
• EHS 0243 - Soldering Awareness Training
• The American Welding Society:
http://aws.org/w/s/technical/facts/index.html
•
Welding Guideline:
www.gov.mb.ca/labour/safety/pdf/welding_guide.pdf
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