Oxyfuel (Oxyacetylene) welding A Complete Guide To Gas Welding

  • By: Paul Dixon
  • Date: June 9, 2023
  • Time to read: 12 min.

Oxy-fuel welding is a process that involves a mixture of fuel gases and oxygen to generate heat for fusing metal parts. Propane, natural gas, and acetylene may be used as fuel gases. A torch is used to reach the necessary temperatures. For many, this is a preferred method due to its control and versatility in various environments.

This technique requires expertise to brazing, soldering, cutting, and welding, to join different metals. It is efficient in thin or thick materials, with precision and control. Minimized distortion during final welds is a result.

The process of oxy-fuel cutting combines oxygen with hot metal carbon to form oxide slag. This helps cut through material by oxidizing it, giving edges a grainy appearance.

The American Welding Society standards document AWS B2.1:2008 Specification for Welding Procedure and Performance Qualification refers to this process as gas welding (oxyfuel).

Equipment Needed for Oxy-fuel Welding

To fulfill your welding requirements with Oxy-fuel welding, you need to arrange the equipment needed for the process. The primary equipment includes gas cylinders, welding torch, regulators, hoses, and fittings. Together, they play a crucial role in ensuring a successful welding process.

Gas Cylinders

Gas cylinders are a must-have for oxy-fuel welding. They contain the gases, like oxygen and acetylene, that welding needs. Without these cylinders, oxy-fuel welding is not possible.

To learn the varieties of gas cylinders used in oxy-fuel welding, check out this table:

Column 1Column 2
Gas TypeCylinder Capacity (in liters)
Oxygen10, 20, 40, or larger
Acetylene10, 20, or bigger
Propane9.1 to 45.4

It’s vital to be careful when dealing with gas cylinders. Experts suggest attaching them upright when in use and storing them away from heat sources.

Empty gas cylinders must also be disposed of properly. Otherwise, they can still be hazardous.

An example of what can happen when not following the right safety protocols: A welder let their gas cylinder go unsecured. It fell over and caused extensive damage to the work area and equipment nearby. This incident shows why it’s so important to handle gas cylinders with care and follow safety steps.

Welding Torch

The Flame Gun, commonly known as a Welding Torch, is a vital part of Oxy-Fuel welding. It provides a directed flame for melting and joining two metal surfaces.

This table outlines the components of a typical Welding Torch:

HandleFor easy grip and control.
Oxygen ValveTo regulate oxygen mix with fuel gas.
Fuel Gas ValveTo regulate flow of fuel gas, e.g. acetylene & propane.
Mixer NozzleTo mix oxygen and fuel gas for combustion.
Tip/NozzleTo direct flame towards metal surface.

Different sizes, shapes and designs of these components are available based on the manufacturer’s specifications.

Welding Torch users must wear proper Personal Protective Equipment (PPE), such as welding gloves, goggles, and apron.

Pro Tip: Choosing the right size and type of torch tip based on the metal thickness makes a huge difference in getting quality welds.


When oxy-fuel welding, precise control of fuel and oxygen is needed. An important tool for this is an Oxy-fuel regulator. Here is a table with its specs:

Regulator TypeSingle Stage/Two Stage
Working Pressure Range0-15 PSIG/0-60 PSIG
Delivery Pressure Range0-5PSI/0-50 PSI
Inlet Connection SizeCGA V-1 / CGA540
Outlet Connection SizeHose barb for 3/16 inch ID hose

Single-stage regulators work best for constant pressure systems. Two-stage regulators work best for fluctuating gas requirements.

Compatibility with torches, hoses, and tips should be considered when selecting a regulator.

A tip: Store regulators in dust-free areas to avoid contamination and performance problems.

Hoses and Fittings

For oxy-fuel welding, hoses and fittings are essential. They connect the welding torch to oxygen and fuel sources using valves and regulators.

We have made a table to show data about hoses and fittings:

Twin HoseConnects both oxygen and fuel gases
Single HoseConnects either oxygen or fuel gas
RegulatorControls pressure of gases
Check ValveStops backflow in hoses

The Twin Hose connects both oxygen and fuel gases. Single Hose only connects one. Regulators control pressure of gases to avoid harm or damage. Check Valves stop backflow in case of an accident.

High-quality hoses and fittings designed for oxy-fuel welding are important. This is to ensure safety.

Industrial Safety & Hygiene News says over 2,000 workers suffer from eye injuries due to faulty industrial equipment each day. So, proper safety precautions should always be taken when working with Oxy-fuel Welding.


Types of Flames Used in Oxy-fuel Welding

To understand different types of flames used in oxy-fuel welding with neutral flame, carburizing flame, and oxidizing flame as solutions briefly. Consider the temperature and gas flow rate of each flame carefully to determine which one is appropriate for your welding task.

Each flame type has unique features and properties that affect the weld’s outcome and the resulting weld’s quality.

Neutral Flame

Oxy-fuel welding utilizes unique flames with distinct applications. The ‘balanced flame’ is another name for the neutral flame, which offers steady performance. It has equal proportions of oxygen and acetylene, providing a controlled heat output.

The neutral flame has an inner blue cone from complete combustion of acetylene and oxygen. The outer envelope of the flame is light-colored due to atmospheric gases. Its heat output can be adjusted by changing oxygen or acetylene flow rates.

Neutral flame is great for mild steel, cast iron, or stainless steel, but also preheating or post-weld heating. Its low heat output prevents warping.

Pro Tip: A stable and consistent neutral flame is easy to use for novices and reduces distortion risks. Tuning the fuel gas and oxygen pressures improves efficiency for metal cutting and brazing.

Carburizing Flame

Oxy-fuel welding has a reducing flame known as the carborizing burn.

This flame works on a low ratio of oxygen-to-fuel, with mostly fuel used. The combustion produces soot and acetylene, creating an outer layer to increase post-weld properties.

The flame is not as focused because of low-pressure gases and low temperatures. It creates a strong layer of carbon, which can withstand wear and deformation. Thus, it is perfect for tool production.

It is worth noting that too much carbon (over 0.6%) reduces ductility. Still, carburization during welding improves wear resistance and reduces brittleness. This is confirmed by reliable sources.

Oxidizing Flame

An oxygen-rich flame is used in Oxy-fuel welding. It’s called an Oxidizing Flame. This flame helps increase oxidation by adding more oxygen to the fuel. The blue cone at the end is long and narrow. The inner region is lighter and bluish.

The table below explains features and applications of the Oxidizing Flame:

Strongly exothermicCutting & brazing
Higher temperatureMelting metals quickly
High concentration of OxygenCopper, aluminum & stainless steel

The oxidizing flame also produces a loud roaring sound and a bright light. This shows enough oxygen inside of it. During WWII, oxy-acetylene welding was used a lot in shipyards. People there constructed entire ships using oxy-acetylene welding torches. Over time, oxy-fuel cutting tech advanced. This allowed for thicker plates to be cut using oxifuel machines.

It’s important to understand different flame types. This helps welders use fuel gas correctly and avoid over or under-heating metals.

Safety Precautions for Oxy-fuel Welding

To keep oxy-fuel welding secure, safety measures must be taken. Here’s a guide to minimize risks while dealing with gas welding equipment.

  1. Inspect Tools: Before using gas welding equipment, inspect all tools. Check for leaks in hoses, regulators, and valves. If any damage or too much wear is present, replace the parts right away.
  2. Personal Protection Gear (PPE): Protect yourself from dangers during welding activities. PPE includes: a welding helmet with a shaded lens, heat-resistant gloves, long-sleeved shirts, closed-toe shoes, and aprons or jackets made of flame-resistant material.
  3. Ventilation Systems: Adequate ventilation systems must be in place during oxy-fuel welding. This stops toxic gases like carbon monoxide or nitrogen oxides from collecting in the workspace.
  4. Proper Storage of Cylinders: Store cylinders upright and secure them with chains or straps when not in use. Always store them in an area with good ventilation and away from flames or hot surfaces.

Moreover, ensure that workers get proper training before operating any gas-welding equipment. Supervise them closely during work hours too.

Set up an emergency plan should something go wrong. Also, encourage workers to report any issues quickly.

By following these safety rules, harm from flammable gases like acetylene can be avoided.

Setting up Your Work Area

To set up your work area for oxy-fuel welding with proper ventilation, lighting, and a safe work surface, follow these sub-sections as a solution for a safer welding experience. Understanding the ventilation requirements to prevent gas build-up, proper lighting to avoid accidents, and choosing a safe work surface to prevent fire hazards creates a safe work environment.

Ventilation Requirements

Having proper air circulation is crucial in any workspace. Especially when dealing with hazardous fumes! Ventilation dilutes and disperses toxic air particulates, protecting against exposure to dangerous substances.

This is a two-step process. First, assess the type and level of contaminants present through air quality testing. Second, choose exhaust fans, or a room-based airflow system, based on test results.

Indoor air pollutants can come from cleaning agents, catered meals, and personal products. So, regardless of the workspace type: industrial or office, regular testing for these sources is essential.

Pro Tip: When selecting an air pressure measure tool, get one that covers multiple sources of indoor pollution. Such as mold spores, VOCs, and CO2 levels.

Proper Lighting

The right level of light is key in getting the work area’s productivity and safety to its peak. Proper lighting means better visibility, which reduces eye strain, headaches, and other vision-related issues. Too little light can make it hard to judge distances, leading to accidents.

Lighting has three types: ambient, task, and accent. Ambient is a general level of lighting that lights up the room evenly. Task lighting is a focused beam for detailed tasks like reading or sewing. Accent lighting shows off certain objects or spots.

For top performance, the light source needs to be in the right spot, have adjustable brightness, have reflectors to maximize the light, and use warm white lights instead of blue ones (for less eye strain).

A friend of mine with RSI couldn’t figure out if her posture or workplace setup was causing the problem until she increased her workspace’s lighting. Optimizing the lighting made it easier to reduce mistakes.

Choosing a Safe Work Surface

Secure Your Worktop

It’s important to think about the surface you work on. A safe worktop helps you work and keeps you away from risks.

Below is a table of materials that can be used as worktops, plus their advantages and disadvantages:

WoodAbsorbs vibration, easy to maintain, durableFlammable, scratches easily
MetalNon-porous, smooth surface; resists heat & water damageCold, hard, noisy, can rust
Plastic/PVCLightweight, non-conductive; resists moisture damageNot heat-resistant, scratches easily

Other factors to consider include appearance, size, and price.

Selecting the correct worktop is essential. It helps create an ergonomic workplace that boosts productivity and keeps you safe. Clear the area around your workstation. This way you have plenty of room to move, and avoid tripping and getting hurt.

Several cases show how essential it is to choose a secure worktop. Poor decisions can lead to lost productivity and injuries, which could have been prevented by setting up a suitable work environment.

Basic Techniques for Oxy-fuel Welding

To master basic techniques for oxy-fuel welding, the key is to focus on the welding positions, starting and maintaining the weld, and ending it. In this section of the “OXY-FUEL (OXYACETYLENE) WELDING – A GUIDE TO GAS WELDING” article, you’ll find solutions presented in the form of sub-sections. These sub-sections include Welding Positions, Starting the Weld, Maintaining the Weld, and Ending the Weld.

Welding Positions

For any oxy-fuel welding job, mastering different positions is essential for high-quality welds. It all depends on the type and shape of materials, as well as the welder’s physical ability.

Check out this table of positions and descriptions:

Welding PositionDescription
FlatHorizontal joint, welding from above
HorizontalHorizontal joint, welding from the side
VerticalVertical joint, welding from top to bottom or bottom to top
OverheadOverhead joint, welding from underneath

Advanced techniques like pipe welding require special equipment and expertise. When choosing a position, factors like comfort and accessibility should be considered. Plus, you need the right training and experience.

Miller Electric Manufacturing LLC give this advice: “There are many types of weld joints and each has its own traits. Understanding them helps you be a better welder.”

Starting the Weld

To begin Oxy-fuel welding, pre-steps are a must for safety and efficiency.

Clean the metal parts with a suitable cleaning agent to remove rust, dirt or oil.

Next, assemble the tools and workpiece – including torch tips and regulators.

Light the torch and heat the metal surface at a 45-degree angle.

Adjust the oxygen and acetylene flames to create a neutral flame when the surface temperature is suitable.

Welding speed and movement should be controlled with steady hands to avoid excess heat damage.

Finally, end the flame supply to finish the arc.

Don’t forget to wear Personal Protective Equipment (PPE) like gloves, face shields and aprons.

Also, make sure the workspace has good ventilation.

If porosity is visible or welds remain molten for too long, reduce heating input quickly.

Maintaining the Weld

After creating an oxy-fuel weld, it’s important to keep it in good condition for safety and lasting results. You can do this with the right techniques. Here’s a 6-step guide for maintaining the weld:

  1. Remove any extra slag or debris using a brush or chisel.
  2. Clean the area around the weld with solvents if it’s greasy or oily.
  3. Check for cracks or defects. Make repairs quickly.
  4. Apply a coating to protect against rust.
  5. Avoid sudden movements that could harm the weld.
  6. Monitor temperature, especially when near heat sources. Too much heat can weaken the weld.

You should also verify the calibration of the equipment, like gas pressure, flame characteristics, and leak detection.

It’s important to follow these procedures since welding damage can hurt people nearby. According to Welding Journal, inadequate supervision of welding equipment has caused accidents.

To sum up, monitoring the weld and following maintenance procedures will keep it safe and reduce repair costs.

Ending the Weld

Once welding is finished, it is essential to end the connection properly. The weld must be finalized without causing any harm or tension to the material. Follow these five steps:

  1. Decrease the flame by turning off the oxygen valve on the acetylene torch.
  2. Turn off the gas supply by moving the handle on the gas torch.
  3. If there are no splatters left, let it cool for a few minutes then use water to terminate heat production.
  4. Chipping hammer can help clean the slag.
  5. Wire brush away all dust and let it cool down.

Be careful when handling hot materials. Don’t touch them with bare hands until they cool. Cleanliness of workspaces also ensures better results and keeps safety protocols.

It is recommended to apply a finishing coat over the cooled workpiece. This will help preserve it from rusting or corroding and increase its durability.

These techniques can help with oxy-fuel welding and bring reliability to your connections.

Common Mistakes to Avoid in Oxy-fuel Welding

Making the wrong flame choice when oxy-fuel welding is a common mistake. This can cause problems: poor welds or even equipment damage. Know which flame is best for the material and adjust accordingly. Not paying attention to the gas flow rate can weaken the weld.

Beginner welders often make inadequate preparation errors. Clean the materials before welding, removing all grease and debris. This ensures adhesion and penetration, leading to stronger welds.

Don’t think all safety gear is the same or unneeded. Wear protection: gloves, helmet with filters, cutting glasses or goggles, and clothing that shields from sparks, flames, gases, and heat.

When oxy-fuel welding is done, clean up. Focus on the equipment being used. Cleaning up ensures machinery health for the next task. Don’t store equipment until it’s cooled down entirely.

Correct flame choice, gas flow adjustments, equipment setup, cleaning workspace, and safety measures will increase success chances.

Troubleshooting Oxy-fuel Welding Problems

Oxy-fuel welding issues? Must address ’em quickly for great results! Here’s a breakdown of common problems and their solutions.

Burnback in the tipTip size too small or low gas pressureIncrease tip size or gas pressure
Hissing sound from the torch tipLow gas pressure or debris in the equipmentClean equipment or raise gas pressure
Poor weld quality with excessive slagIncorrect flame setting or poor material preparationCorrect flame setting. Clean and prepare materials.

Porosity and cracks not resolved? Professional inspection and repair may be needed.

Safety measures are key. Wear protective gloves and eyewear when handling hot metals.

Pro Tip: Regularly check equipment for damage or wear, to avoid potential hazards.

Conclusion: Advantages and Disadvantages of Oxy-fuel Welding

Gas Welding: Benefits and Drawbacks

Oxy-fuel welding, also known as gas welding, offers a range of advantages in metalworking. But it has its own drawbacks which must be considered before choosing this method.

The table below provides an overview of pros and cons of oxy-fuel welding:

Versatility – Can weld various metalsSafety risks – Open flames and high temperatures can be hazardous
Strong joints – Produces strong welds that last for yearsLimited portability – Needs a gas cylinder and other equipment
Cost-effective – Uses simple tools and easily available fuelTime consuming – Slower than other methods
Suitable for outdoor use – Does not need electricity or compressed airDifficulty with thin metals – Oxy-acetylene torch is less effective with thinner materials

Unique details about this type of welding include the effect of the gas mixture on performance and the requirement of training due to its dangers. It’s essential to take safety precautions when conducting oxy-fuel welding.

Interestingly, oxy-acetylene welding has been used since the late 1800s. It was first used to join railroad tracks but has since been applied in various industries like auto and construction.

In conclusion, oxy-fuel welding can be a great choice for metalworkers who want a strong and efficient way to join different metals, if used properly.

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Paul Dixon is a certified welder with a wealth of experience in welding and related technologies. He started his career as an apprenticeship in welding, where he learned the ropes and acquired extensive skills in the craft.

Over the years, Paul has continued to sharpen his expertise, earning him top-rated welding certification. He remains one of the most outstanding welders in the industry.

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