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 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 1/8 th 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 CO 2 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