SetUp Procedure for the Oxyfuel cutting Torch Then

Set-Up Procedure for the Oxyfuel cutting Torch Then we cut

Ag Systems l • Standard 8: Students will fabricate with metal. • Objective 4: Use manual oxy-fuel gas cutting processes. • There are 5 points to meet. • They are as follows

a. Set up for manual oxy-fuel gas cutting operations on carbon steel. b. Perform straight cutting operations on carbon steel. c. Perform shape-cutting operations on carbon steel. d. Perform bevel-cutting operations on carbon steel. e. Pierce a hole through a carbon steel plate.

Importance of Torch Cutting • More people use the oxyfuel cutting torch than any other cutting process. • The cutting torch is used by workers in virtually all areas including manufacturing, maintenance, automotive repair, railroad, farming, and more.

• It is unfortunately one of the most commonly misused processes. • Most workers know how to light the torch and make a cut, but their cuts are very poor quality and often unsafe.

• A good oxy-fuel cut should not only be straight and square, but it should require little or no post-cut cleanup. • Excessive post-cutting cleanup results in extra cost, which is an expense that cannot be justified.

Safety Reminders • Keep oil and grease away from all parts of the oxy-fuel apparatus. • Secure the cylinders in an upright position so they cannot be tipped over. • Face the regulator gauges upward making it impossible to stand in front of them. • Acetylene work pressure should NEVER exceed 15 psi.

• Use an approved spark lighter to light the torch; never use matches or cigarette lighter. • NEVER use oxygen to operate pneumatic tools, blow out lines, inflate tires, dust off clothing or cool yourself off. • NEVER hang clothing on cylinders, running the risk of saturating them with oxygen and acetylene.

• DO NOT walk with a lighted torch or lay down a lighted torch. • DO NOT strike an arc on a cylinder or hit a cylinder with a metal object. • NEVER use a cylinder as a ground in an electrical circuit.

• Dress properly and wear eye protection. • Keep a fire extinguisher handy at all times. • Prevent heat and sparks from getting to cylinders and hoses. • While doing your equipment check if something is not correct notify your teacher.

Set-Up Procedure for the Oxyfuel Torch 1. Check torch body for closed valves. 2. Regulator adjusting screws are to be loose on each (Acetylene and Oxygen). 3. Open acetylene cylinder valve 1/2 to 3/4 turn (wheel-type valves one turn) maximum. 4. Turn acetylene regulator adjusting screw to desired working pressure.

Steps continued 5. Open oxygen cylinder valve completely. 6. Turn oxygen regulator adjusting screw to desired working pressure. 7. Crack acetylene torch valve and light the torch, open acetylene torch valve until soot disappears.

8. Open oxygen torch valve and adjust to a neutral flame; no acetylene feather and sharp inner cone. 9. Oxygen and acetylene settings will vary depending on the attachment tip and thickness of metal to cut.

Review set up • To see set-Up procedure for the Oxy-fuel torch review Click on the button.

Types of Oxyfuel Flames

For best results use a neutral flame for cutting! To see setting a neutral flame click on button

Shutdown Procedure for the Torch 1. Turn off acetylene valve on torch handle (the flame goes out). NEVER turn off oxygen first. 2. Turn off oxygen valve on torch handle. 3. Close acetylene cylinder valve. 4. Close the Oxygen cylinder valve.

5. Bleed acetylene hose by opening acetylene torch valve; (both gauges drop to “ 0”), then close torch valve. 6. Back-out acetylene regulator adjusting screw until loose. 7. Bleed Oxygen hose by opening Oxygen torch valve; then close torch valve. 8. Back-out oxygen regulator adjusting screw until loose.

9. Recheck valves for closure, then roll up hoses. **Clean and organize the cutting area

NEVER • Leave equipment under pressure 24 hours a day. • It reduces the accuracy of the gauges. • Shortens the life of the Hoses and pressure regulators. • Creates unsafe conditions.

Shutdown Procedure for the Torch • To see a System shut down review click button

Cutting Metals

Layout and set-up • The metal to be cut should be clean, marked with a punch, soapstone, or sharpie, and placed in a suitable position for cutting.

Protect the area • To prevent damage where hot metal falls, do not cut over a concrete floor. Use a container or special cutting table device to catch the molten metal. Hot metal can also damage hoses and cause fires.

HOSES. • Oxygen and acetylene hoses should come from behind the cutter

The steps to follow in making a cut are: 1. Hold the torch handle Parallel to the surface of the metal. The cutting tip will be 90 degree square to the metal 2. Unless you are cutting a bevel.

2. Hold the flame inner cone about 1/16 to 1/8 inch above the plate. • The proper distance away from the plate will prevent metal from sticking to the tip.

• Position the tip so that two preheat holes are in line with the cut (one leading the cut, and the other following the cut).

Preheating 3. Hold torch at edge of metal until metal begins to melt (cherry red).

After preheating 4. Press down slowly on the cutting oxygen lever until cutting valve is completely open. • When the cut is through the metal, (you will see sparks from under the steel) move the torch along the mark.

• Top of torch may be slanted toward the cut & changed to a vertical position as the cut progresses

• 5. Move the torch slowly along the marked surface or the oxygen stream will not pass completely through thick metal. • Watch the sparks coming from under the plate to see if it is burning completely through.

Rolling your hands Cutting Techniques • “Pre-load” your wrist and forearm, roll don’t slide along the plate for a smoother cut.

Recommendations for cutting thin steel. • Tilt the torch tip toward the direction of cut on thin metal, Notice that the two preheat flames are in line with the cut (kerf).

Losing a cut • To restart the cut, release the cutting lever and reheat the metal again before pressing the cutting lever. • Just like starting the cut to begin with. • Losing the cut may cause irregular edges.

Starting or restarting a cut Resume Cutting Heat thethe starting point Move oxygen hole off the edge of the plate and start the oxygen stream

Oxy acetylene cutting review • To see a System shut down review click button

BEVELING MILD STEEL • Frequently, you must cut bevels on metal plate or pipe to form joints for welding. • The flame must actually cut through more than the thickness of the steel. • You must take this into consideration when selecting the tip and adjusting the pressures.

beveling • You use more pressure and less speed for a bevel cut than for a straight cut. • When beveling plate edges or cutting at an angle, lean the tip at the desired angle and hold the torch handle parallel to the work. A piece of 1 -inch angle iron, with the angle up, makes an excellent guide for beveling straight edges.

Beveling Angles Techniques • Apply pressure to torch tubes with thumb and index finger. • Slide the torch through your fingers toward you. • Keep other three fingers in fist This will keep your hands cooler and allow you to make a better cut.

Steps to follow when piercing holes with the Oxy-acetylene torch.

• 1. Hold the torch handle Parallel to the surface of the metal. The cutting tip will be 90 degree square to the metal. • Hold the tip about 1/4 to 5/16 inch above the plate surface.

• 2. Heat the surface until a spot on the surface begins to melt. • Don’t get in a rush, when the spot is cherry red.

• 3. Raise the torch until the tip is about 1/2 inch from the surface and slowly press the lever as the torch is raised. • Tilt the tip to one side of the heated area so that the slag can be blown away not back into the tip. Tilted

• 4. When flame cut penetrates the plate (you will see sparks under)tilt the torch back to square with the plate surface. • Move the inner flame cone within about 1/8 inch from the surface and make the cut on the inside edge of the hole.

Piercing Review • To see piercing a hole with the Oxyacetylene torch review click button:

Piercing a hole • Doesn’t always mean a bolt hole. It could be for a pipe or a tube or some shape.

Think about it • What material is scrap and what material is going to be the part you are making? • Pierce and start the cut in the scrap material then move to the line for the part edge.

Thick metal • For easier cutting of a hole in thick metal, drill a hole 1/4” diameter or larger and start the piercing in this drilled hole.

Troubleshooting the cutting process

How do I know if I cut right? • There is more to it than just that the piece of metal fell off. • If my skills improve will cut edge cleanup time be reduced? • Oxy-acetylene cutting skill is something welders need to have. • Welders need to keep sharp through practice.

American Welding Society Cut Quality Cut Irregular Pressure Extremely Fast Extremely Slow

Correct Cut • Notice that the top edge is square and that the drag lines show a slight curve.

Oxygen Pressure Too Low • Produces a cut with rough surface, makes it difficult to hold cut and results in slow speed with too much lag.

Speed Too Fast • Produces a rough cut with pronounced drag line very similar to too low oxygen pressure.

Oxygen Pressure Too High • Produces a rough surface, melts down top edge and wastes oxygen.

Too Much Acetylene in Preheats • Reduces cutting speed approximately 25%. Forms carbon deposits on cut surface and wastes acetylene.

Correct Cut • Here the factors of tip size, pressures and speed are correct…results in square top edge and uniform narrow kerf.

Preheats Too Heavy • Top edge is melted down, kerf irregular and excess gas is consumed by the preheat flame.

Preheats Too Small • Wastes time as maximum speed cannot be obtained. Low cutting speed results in gouges at bottom edge of cut.

Oversize Tip • Produces a kerf which is too wide, causing not only a waste of plate but also a waste of both gases.

Undersize Tip • Inefficient cut because piece will not drop when end is reached as slag has not cleared the kerf and cutting time will be excessive.

4 rule review • To see review click on button

The cutting assignment can be very specific or general. • Teacher decides material to use, measurements , accuracy tolerance, etc… based on the materials and equipment on hand. • The assignment should include: Straight cut, Bevel cut, Radius cut, and Pierce the plate cut a hole or shape.

Time for the cutting assignment

The end