oxy-fuel welding - mrs. bishop's agriculture courses -...
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Oxy-Fuel Welding
What is Oxy-Fuel Welding?
Process the fuses metal
together
Does not require
electricity
Uses a torch and filler
rod
Similar equipment as
Oxy-Fuel Cutting
Where is Oxy-Fuel Welding used?
Maintenance
Body Shops
Repair of small parts
Useful for preheating
Hardening
Annealing
OFW Principles
Torch creates heat from flame
Heat creates moltenpool on metal
When molten pools on two pieces combinethey create one piece
When pieces cool, they are fused together
Filler rod can be added
Gives additional
strength to weld
Filler made of same
material as pieces
being joined
OFW Safety
Heat from flame = hot enough to burn most anything
Watch where you aim the torch
Keep work area clean
Remove any flammable material from work area
Always keep a fire extinguisher on hand
Frayed clothing will catch on fire
No synthetic clothing
Wear appropriate footwear
Always wear safety glasses
Keep oil based products away from torch equipment
OFW Equipment
Cylinders (Oxygen + Acetylene)
Regulators
Hoses
Torches
Tips
OFW Equipment- Cylinders
Oxygen Cylinder
Made of seamless
drawn steel
Bottle valve always
opened all the way
Protective cap used
when cylinder not in
use
High Pressure Bottle
Acetylene Cylinder
Packed with porous
material
Saturated with acetone
Used in vertical
position
OFW Equipment-Regulators
Control flow of gas from cylinder to working
pressure
Produce steady flow of gas under varying
cylinder pressures
Must be handled carefully, especially when
not on the cylinder valve
OFW Equipment- Primary Regulators
Control the flow of
gases from cylinder to
manifold
PSI ranges set higher to
accommodate the
multiple work stations
Safe handling needs to
be considered at all
times
OFW Equipment-Secondary
Regulators
Regulators for each
booth
Control flow of gases
from primary regulators
to individual work
stations
Smaller design,
operation is the same
OFW Equipment-Hoses
Oxygen Hose = Green
hose
Normal direction
threads
Acetylene (Fuel) Hose =
Red hose
Reverse direction
threads
OFW Equipment- Torch Body
Standard torch body
Has Oxygen Torch Valve and Acetylene Torch Valve
Used for Oxy-Fuel Cutting (OFC) or Oxy-Fuel Welding (OFW)
Gases do not mix in torch body
OFW Equipment- Torch Tips
Removable tip used to
mix gases and direct
the flame
Tips come in a variety
of sizes to weld variety
of metal thicknesses
Common tips sizes: 00,
0, 1
Tip cleaners used to
break up any impurities
that have entered the
opening of the welding
tip
When not in use, tips
are stored in a holder
Care of Torches
Torches need to be handled carefully
When not in use they need to be hanging up
on hooks
Never lay a torch on a table especially
without a welding tip attached
Never lay a tip on the table
Be sure to use the correct size cleaner for the
correct size tip
OFW Equipment- Miscellaneous
Safety glasses
Welding/cutting goggles
Gloves
OFW Equipment- Miscellaneous
Protective clothing
(arms and legs
covered)
Strikers (non-flame
source igniters)
Tip Chart
OFW Set Up- Opening the Bottles
Check that the “T” screws on regulators are
loose
Stand behind the valve and regulator
Slowly open the bottle valve
Once pressure has entered the regulator, turn
the oxygen bottle valve on all the way
Acetylene bottle valve is only turned on one
twist of the wrist (1/4 turn)
OFW Set Up- Adjusting the Primary
Regulators
Twist the “T” screw on Oxygen regulator in, so that the pressure increases.
Bring the needle up to 20 psi
Twist the “T” screw on acetylene regulator in, so that the pressure increases.
Bring the needle up to 5 psi
OFW Set Up-Adjusting the Secondary
Regulators
Open the oxygen valve on the torch
Twist the “T” screw on Oxygen regulator in, so that the pressure increases.
Bring the needle up to 3-5 psi
Close the valve on the TORCH BODY
OFW Set Up-Adjusting the Secondary
Regulators
Open the acetylene valve on the torch
Twist the “T” screw on acetylene regulator in, so that the pressure increases.
Bring the needle up to 3-5 psi
Close the valve on the TORCH BODY
OFW Operation-Lighting the Torch
Open the Acetylene valve 1/8th of a turn
Using a striker, light the torch so that a flame
appears from the end of the tip
Add more acetylene until a desired flame is
present
Flame should be feathery at the end with no
heavy soot coming from the smoke
OFW Operation-Lighting the Torch
Using the oxygen valve, add more oxygen
until a blue feather appears in the flame
Add more oxygen until the feather comes
down to the points on the inner cone
Sound should have a light rushing noise
OFW Operation- Types of Flames
Neutral flame = desired type of flame
Creates CO2 to purge oxygen away
Reducing or Carburizing Flame = too much Acetylene
Preheat flames wont sharpen
Oxidizing Flame = too much oxygen
Loud rushing noise, too much heat (localized overheating)
OFW Operation- Types of Flames
OFW Operation- Running a Bead
Bring inner cone 1/8”- ¼” away from edge of metal
Make a small circular rotation to create a “heat zone”
Orange/yellow color will appear
Small dot will take shape= molten pool
Circle molten pool up to a diameter of 1/8”
Work circular rotation to “push” the puddle from right to left
OFW Shut Down
Turn off acetylene valve on torch
Turn off oxygen valve on torch
Put torch on hanging holder
Take tongs and quench metal
Be careful while working around tables, as bricksare hot!
OFW Clean Up
Shut secondary valves off in each booth
Open the valves on torch to bleed gas from hoses
T screws on secondary regulators twisted twotwists of the wrist out
Clean up all scrap metal from booths (be careful of hot metal)
OFW Clean Up
Clean up all rod and put into scrap rod bucket
Torch hoses need to be looped on hook
Torches on holder
Strikers on back wall of each booth
Tips into holders, stools stacked on table top
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