How to Use Oxy-acetylene Torch for Cutting?

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how to use oxy acetylene torch for cutting? It is valuable question in the field of  metal fabrication. Oxy-acetylene, or commonly known as acetylene metal cutting or welding, is one of the most common methods preferred in the welding industry. Acetylene gas is formed by combining water with calcium carbide. When oxygen and acetylene are combined in cutting torch, a hot flame of more than 6,000F 3300 o C is propagate, which is enough to cut any metal object. How to use an oxy-acetylene torch for cutting is an art that requires one to be keen.

Currently, acetylene welding is preferred than electric welding simply because it is cheap, versatile, and portable. Acetylene welding requires an individual who is trained or has experience because acetylene welding can be dangerous for an amateur even though learning the art is not that difficult as many people think.

-Before lighting the oxy-acetylene torch follow these check list:

  • Make ensure the regulator pressure adjustment screws are backed out!
  • Make ensure both (oxygen and acetylene) torches valves are properly closed!
  • Keep away yourself from front of pressure regulator
  • Then, slowly open the oxygen cylinder valve and then the acetylene cylinder valves
  • Unscrewing pressure regulator screws to require torch tip pressure settings
  • Tune torch valves one by another and make sure required pressure settings on regulators again
  • Press cutting torch lever and adjust pressure if need further.
Fig. Oxy acetylene Cylinder, Regulator and Cutting Torch

Fig. Oxy acetylene Cylinder, Regulator and Cutting Torch

-Lighting and adjusting the fine tuning valve of oxygen and acetylene of cutting torch:

  • First Purge oxygen gas from hose line and then purge the fuel gas from line
  • Open the line of acetylene gas valve (about-1/2 turn)
  • Ignite the flame of torch tip with Vesta
  • Increase flow of acetylene gas until flame leaves end of tip.
  • Tune the valve until flame goes back to tip
  • Open oxygen valve and adjust for the neutral flame
  • Again press oxygen lever and make required cutting flame
Fig. Neutral Flame

Fig. Neutral Flame

-Procedure of Shutting down the torch:

  • First, close the oxygen torch valve
  • Second, close the fuel/acetylene gas torch valve

-If the cutting has been done then follow the procedure for stop the work:

  • Turn off the cylinder valves of oxygen and fuel gas
  • Make sure, purge oxygen and acetylene gas lines
  • Make 0 psi in all pressure regulator
  • Adjustment the screws of regulator pressure back out!  

Adjusting Regulator on Oxy-Acetylene Cylinder for required Pressure:

Gas pressure regulators are crucial for distributing oxygen and acetylene in a required proportion to a cutting torch that is safe from high-pressure cylinders. Typical gas pressure regulator have a control device, a loading mechanism, and a sensor. All these devices work in unison to regulate the pressure and gas mixture.

Spring is usually the loading mechanism that regulates the delivery of pressure. The spring compresses when the gas regulator knob is turned. The turning of the knob will trigger setting distribution pressure by displacing the sensing device. The sensory device is simply a diaphragm made of metal or elastomers. After the diaphragm is displaced, it pushes the valve in the control element, provoking the valve to supply the flow of pressure needed by increasing its size.

Setting Oxy-Acetylene Torch:

Before setting the cutting torch, make sure you check all the equipment. Be certain that all the cutting torch components are correctly connected and that there are no leaks or couplings that are loose. Check whether the gauges and hoses are properly connected to their respective gas cylinders.

Don't also forget to look at the flashback arrestors. 5 PSI is the recommended pressure setting of the acetylene tank. There are also suggestions that the oxygen pressure should be kept at 10 PSI, and pressure should not go above 15 PSI.

Operating Acetylene Torch:

Before turning on the cutting torch, make sure you inspect all the torch equipment. Check whether all the gas cylinders are properly fastened because they can fall if not well fastened. Next, check the hoses and make sure that they are not rotted or cracked. Regulators should also be reading zero, connectors should be tight and cylinders closed.

After determining that all the gauges are functioning as required, the next task is to make sure that spring pressure is not felt by backing up regulator screws.

Turning On the Acetylene Torch:

Before turning on the torch, protective gear is needed. Wear gloves, shade ANSI eyewear, etc. Inspect chains on bottles, hoses, valves, gauges, and the torch. Zero out gauges by purging lines if gauges are not reading zero.

Slowly open the oxygen cylinder valves and according to the manufacturer's instructions and select the right tip. Next, determine the pressure setting using the manufacturer’s manual. Then set the gauges and individually purge the lines.

Lastly, turn the torch valve by ¼ and light the cutting torch. Increase the flame until soot disappears and then adds oxygen to the acetylene flame. Now you are ready to use the torch.

Turning off Acetylene Torch:

After completing all metal cutting operations, this how you are supposed to turn off your cutting torch.

Step 1: Start by turning off the valve on the oxygen preheat then close the cutting torch fuel valve. Remember not first to shut off the fuel valve because this may lead to a pop sound.

Step2: The next step is to shut off all the control valves on gas cylinders to cut off the gas supply.

Step 3: Depress the cutting lever and open the oxygen valve. Make sure all the pressure has come out of the system and then shut off the oxygen control valve on the handle. Finally, turn off the oxygen preheat.

Step 4: Release all the spring pressure by adjusting the oxygen controller anticlockwise.

Step 5: Close the fuel valve after releasing all the pressure from the system by opening the torch's fuel regulator valve.

Step 6: Make sure that the spring pressure is released by adjusting the fuel gas regulator screw.

Step 7: Ensure that no pressure remains in the system by checking the inlet gas gauges after a couple of minutes.

Step 8: Finally, check the cut edge and remove the slag if left by using a brush or chip hammer. It is wrong to use the cutting tip or torch head to remove the slag from the edge.

Oxy-acetylene torches are currently being used to create a variety of welding materials. Whether you are salvaging, cutting any metal, all you need is acetylene torch.

Important Terminology of Gas Torch Malfunctioning

Popping Acetylene Torch

There are a couple of reasons that can make a cutting torch to pop. Below are some reasons.

Backfiring

Backfiring should not worry you because it is a minor issue that can only irritate the welder. Backfiring is typically caused by a flame that enters the nozzle with a loud sound that pops. This flame may go off entirely, or sometimes it might re-ignite.

Sustained Backfiring

Sustained backfiring is a more complicated problem that is brought about by a flame that stays longer in the cutting torch. As the flame burns a pop sound followed by a whistling or a hissing sound is heard. In the case of this instance, immediately turn off the gas.

Flashback

Flashback is caused by a flame that is not going inside the torch, and it might be running back into the supply system or up the line. This can be dangerous because the hose is likely to burst, or the tank can blow due to the high pressure from an internal explosion. The remedy to this is installing flashback arrestors on the inlets and regulator outlets.

Backflow

This usually is volatile. This is caused by low-pressure acetylene gas that is pushed back by high-pressure oxygen gas hence mixing in the hose. This setback can also be solved by installing arrestors.

Dirty Nozzle

A dirty nozzle can hinder the proper flow of acetylene and oxygen gas. When the two gases don't correctly mix, a flame may go off or a loud pop sound is heard. Look at the nozzle, and if you notice a black tip wash it using a brush that is wired with brass.

Improper Flow Settings

When flow settings are not properly set, popping can also be witnessed. Usually, when you buy a cutting torch, you are provided a booklet with operation guidelines. Make sure you follow them when setting the flow.

Many industries dealing with metals are now using acetylene torch in their daily activities. Plumbers, automobile manufacturers, and welders use this type of technology.

This type of technology can be learned by taking some classes or from an experienced welder. When working with this torch, one is always supposed to practice safety measures because they can be dangerous when not properly handled.

Last Updated on May 25, 2021 by weldinghubs

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