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 molten pool on metal

When molten pools on two pieces combine they 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 25 psi

Twist the “T” screw on acetylene regulator in, so that the pressure increases.

Bring the needle up to 8 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 bricks are 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 two twists 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