Chapter 2 Safety in Welding - Area10FFA
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Transcript Chapter 2 Safety in Welding - Area10FFA
Chapter 2
Safety in Welding
Objectives
Burn classifications and emergency treatment
Dangers of types of light, and avoiding eye and
ear injuries
Use a chart to select eye and face protection
Describe various types of respiratory protection
Avoid dangerous fumes and gases
Objectives (continued)
The purpose of Material Safety Data Sheets
The benefits of recycling waste material
General work clothing and special protective
clothing
Safely handle, secure, and store cylinders
Protect against fire danger when welding
Objectives (continued)
The importance of planned maintenance
Tools commonly used by welders
Good electrical safety practices
Types of metal cutting machines
Safely lift heavy assemblies
Ladder safety
Introduction
No substitute for caution and common sense
Each person must take personal responsibility
Welding has a number of potential safety hazards
Most large welding companies have mandated
safety classes
Burn Classification
Burns are one of the most common and painful
injuries
Caused by ultraviolet light rays and contact with
hot welding torches
All burns must receive proper medical treatment
Burns are divided into three classifications
First-Degree Burns
The surface of the skin is reddish
Tender and painful
No broken skin
Put the burned area under cold water or apply a
cold compress
Cover the area with sterile bandages
Never apply butter or grease
Second-Degree Burns
The surface of the skin is severely damaged
Blisters and possible breaks in the skin
Put the area under cold water or use cold water
compresses
Pat the area with a dry lint-free towel and cover
with a sterile bandage
Seek medical attention
Figure 2-2 Second-degree burn
Third-Degree Burns
Surface of the skin appears white, charred
Never remove any clothing
Never put ice water or ice, ointments, sprays, etc.
If the victim is on fire, smother the fire with a
blanket, rug or jacket
Cover the burn with a thick sterile dressing
Call for an ambulance
Burns Caused by Light
Some types of light can cause burns
Three types of light include:
– Ultraviolet
– Infrared
– Visible
Arc welding produces all three types of light
Light from the welding process can be reflected
from walls, ceilings, and floors
Ultraviolet Light
The most dangerous
Causes first and second degree burns to eyes or
exposed skin
The closer the welder is to the arc and the higher
the current, the quicker a burn may occur
A welder's eyes can receive a flash burn in
seconds
Figure 2-6 The eye can be burned on the white or retina by ultraviolet light.
Infrared Light
The light wave is felt as heat
A person will immediately feel this type of light
Burns can be easily avoided
Protective action should be taken to cover
yourself
Visible Light
The light that we see
Produced in varying quantities and colors
May cause temporary night blindness
Too little visible light may cause eye strain
Visible light is not hazardous
Face Eye and Ear Protection
Eye protection must be worn in the shop at all
times
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Safety glasses with side shields
Goggles
Full face shield
Flash glasses
Welding light damage often occurs without
warning
Welding Helmets
Even with quality welding helmets, the welder
must check for potential problems
Undetectable leaks of ultraviolet light can cause a
welder's eyes to itch or feel sore
Ensure lens gasket is installed correctly
Tape can be used as a temporary repair
Safety Glasses
Adequate for general use
Not suitable for heavy grinding, chipping, or
overhead work
Must be worn under an arc welding helmet
at all times
Ear Protection
Welding environment can be very noisy
Hot sparks can drop into an open ear, causing
severe burns
Earmuffs cover the outer ear completely
Earplugs fit into the ear canal
Damage caused by high sound levels may not be
detected until later in life – hearing will not
improve with time
Respiratory Protection
Welding and cutting produce harmful by-products
Respirators protect against welding by-products
Welders are responsible for following the shop's
written respiratory protection policy
Training should include:
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Proper use of respirator
Maintenance schedules and respirator selection
Procedures for testing the proper fitting and use
Regular evaluation of the program
Equipment
Some types of respiratory protection equipment:
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Air-purifying respirators
Atmosphere-supplying respirators
Demand respirators
Positive pressure respirators
Powered air-purifying respirators
Self-contained breathing apparatus
Supplied-air respirators
Fume Sources
Paints, coating, or plating on metals can cause
respiratory problems
Before welding or cutting any painted metal, the
surface must be cleaned
Marine industry still uses lead-based paints
Exposure to cadmium fumes can cause lung and
kidney damage
The best way to avoid problems is to provide
adequate ventilation.
Vapor Sources
Ozone gas is produced by ultraviolet radiation
Ozone irritates mucous membranes
The collection of fumes and gases can go
unnoticed
Concentrated fumes can cause a fire or
explosion
Ventilation
Welding area should be well ventilated
Natural ventilation is best
Forced ventilation may be required
Large enough areas may not require forced
ventilation
Figure 2-15 A room with a ceiling 16 ft. high may not require forced ventilation
Forced Ventilation
Small shops or shops with many welders require
forced ventilation
Forced ventilation
– Can be general or localized
– Fixed or flexible exhaust pickups
Forced ventilation is required when welding on
metals that contain dangerous fumes
Material Safety Data Sheets
Material safety data sheets (MSDS) provide
details of possible hazards
Often posted on a bulletin board or put in a
convenient place where products are used
If injured while using a product, take the
material's MSDS when you seek treatment
Waste Material Disposal
Welding shops generate a lot of waste materials
All scrap metal can be recycled
Hazardous waste materials include:
– Burned flux
– Cleaning solvents
– Dust collected in the filtration system
Throwing hazardous material away is illegal
General Work Clothing
Guidelines for work clothing:
– Shirts must be long-sleeved
– Pants must be long enough to cover the tops of
the boots and must be without cuffs
– Boots must have high tops
– Caps should be thick
– Clothing must be free of frayed edges or holes
There is no safe place to carry a butane lighter or
matches while welding
Special Protective Clothing
Extra protection is needed for each person who is
in direct contact with hot materials
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Hand protection
Body Protection
Waist and Lap Protection
Arm Protection
Leg and Foot Protection
Leather is often the best material to use
Handling and Storing Cylinders
Store oxygen and fuel gas cylinders separately
Store inert gas cylinders separately or with the
same type of fuel cylinders
Store all cylinders vertically
Securely fasten the protective cap
Securing and Storing Gas Cylinders
Secure cylinders with a chain or other device
Chain cylinders attached to a manifold or stored
in a special room
Cylinder storage area must be away from halls,
stairwells, and exits
Storage areas should be away from heating units
and welding sparks
Secure storage areas from unauthorized people
Cylinders with Valve Protection Caps
Must have the cap in place unless the
cylinder is in use
The cap prevents the valve from being broken off
Never lift the cylinder by the safety valve
When moving cylinders, the valve protection cap
must be on
All cylinders must be handled with care
General Precautions
Any cylinders with a defect must be identified
If a leak cannot be stopped
– Move cylinder to a vacant lot
– Slowly release pressure
– Post a warning sign
Acetylene cylinders
– Must be upright for four hours before use
– Otherwise may draw acetone from the cylinder
Figure 2-25 Move a leaking fuel gas cylinder out of any work area
Fire Protection
Fire is a constant danger
Highly combustible materials should by 35 feet
away from any welding site
A fire watch can be provided by any person who
knows how to sound an alarm
The fire extinguisher must be the type required to
put out a fire for the type of combustible material
Fire Extinguishers
There are four types of fire extinguishers
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Type
Type
Type
Type
A: combustible solids
B: combustible liquids
C: electrical fires
D: fires involving combustible metals
Some fire extinguishers can be used on more
than one type
Using the wrong type of extinguisher can be
dangerous
TYPE A FIRE
TYPE B FIRE
TYPE C FIRE
TYPE D FIRE
Location of Fire Extinguishers
Fire extinguishers should be easily removed
Should be easily lifted
Location marked with red paint and signs
Should be marked near the floor
LOCATION
Use
Extinguishers cool the fire and remove oxygen
Use foam, carbon dioxide, a pump tank, or dry
chemicals
CO2 extinguisher – direct the discharge as close
to the fire as possible
Dry chemical extinguisher – direct toward the
base of the flames
Figure 2-34 Point the extinguisher at the material burning, not the flames
Equipment Maintenance
Planned maintenance (PM) detects problems
Hoses must be used for the gas or liquids for
which they were designed
– Green hoses are used only for oxygen
– Red hoses are used only for fuel gases
Never use oil grease, or other pipe-fitting
compounds on joints
Any leaking joints must be repaired
Work Area
Should be picked up and swept clean
Arc welding area painted with a flat dark color
Portable screens used if welding outside the
welding booth
If a piece of hot material is left unattended, write
hot on it before leaving
Hand Tools
Used for assembly and disassembly of parts
The adjustable wrench is the most popular tool
Fewer points = stronger
Mushroomed heads of chisels, punches, and the
faces of hammers should be ground off
Always use the correct tool for the job
Electrical Safety
Injuries and death can be caused by electrical
shock
Resistance is lowered in the presence of water or
moisture
Electrically powered machines must be grounded
Welding circuits must be turned off when the
work station is left unattended
Electrical Safety Systems
Two safe systems for electrical power tools:
External grounding
– A wire runs from the housing to a third prong
– Third prong plug fits into grounded receptacle
Double insulation
– Extra layer of insulation
– Eliminates need for grounded outlet
Voltage Warnings
Voltage is the same as specified on the tool
A voltage greater than the tool can lead to injury
A voltage lower than the tool can damage the
motor
Amperes (Amps) measures electrical current
Extension Cords
Use only three-wire, grounded extension cords
When using extension cords:
– Connect the cord of tool into the extension first
– Extension cords should be long enough
– The cord does not come in contact with sharp
objects
– Check for loose or exposed wires
– Clean before storing
Figure 2-41 Two types of grounding plugs
Safety Rules for Portable Electric Tools
Some general rules:
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Know the tool and ground the tool when needed
Do not expose to water
Keep the area well lighted
Do not use near propane, or flammable vapors
Wear eye protection
Secure your work with clamps
Maintain power tools
Grinders
Grinding using a pedestal or portable grinder is
required to do many welding jobs
Before a grinding stone is put on a machine, it
should be tested for cracks
Each grinding stone is made for grinding specific
types of metal
Stone should not be used when are worn down
Gloves should never be worn when grinding
Drills
Center punch holes before drilling
If the bit gets caught, stop the motor
Securely clamp all metal before drilling
Sharp metal shavings should be avoided
Metal Cutting Machines
Before operating any power tool for the first time,
read the manufacturer's instructions
Welders use shears and punches in the
fabrication of metal for welding
Cut off machines use abrasive wheels or special
saw blades
Band saws are vertical or horizontal
– Some can be used in either position
Material Handling
Improper work habits can cause serious personal
injury
Improper handling can cause damage to tools
and materials
When lifting, the weight of the object should be
evenly distributed between both hands
The capacity of hoists or cranes should be
checked before lifting a heavy load
Ladder Safety
Improper use of ladders is often a factor in falls
All ladder use poses a danger
In case of a fall, keep the area around the ladder
clear
Step ladders and straight ladders are used
extensively in welding shops
Figure 2-52 Make sure the ladder is leaning at the proper angle.
Ladder Inspection and Safety
Over time, ladders can become damaged
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Look for loose or damaged parts
Check that all hardware is tight
Check wooden ladders for cracks
Never use a defective ladder
If a ladder cannot be repaired, replace it
Read the entire ladder manufacturer's list of safety
rules for ladder use
– Never use a ladder that is too short for the job
– Climb and descend cautiously
Summary
Safety is of the utmost importance
The safety officer ensures welders comply with
safety rules
Wear proper clothing, shoes, and protection
Have established plans in case of accidents
Check equipment periodically
Further information is available in Safety for
Welders by Larry E. Jeffus