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