Orbital TIG Welding [Our 2024 Guide]

At its core, Orbital TIG welding involves the automated circumferential welding of pipes, tubes, and other cylindrical components.

This method is particularly vital in industries where high-quality, repeatable welds are a necessity — such as in aerospace, pharmaceuticals, and the energy sector, including nuclear and pipeline construction.

What sets Orbital TIG welding apart is its ability to maintain consistent weld quality even in the most challenging positions and environments, where manual welding might falter.

This precision comes from the unique combination of controlled inert gas shielding, automated torch movement, and the precision control of welding parameters.

The result? Strong, clean, and highly repeatable welds that are essential in high-specification environments.

This article is crafted for you, the welder who already grasps the basics of welding.

We assume you’re familiar with concepts like arc welding, filler materials, and the importance of shielding gases. Our goal is to elevate your understanding of Orbital TIG welding, guide you through its nuances, and help you master this advanced technique.

Whether you’re looking to refine your skills, tackle new challenges in your welding career, or simply curious about what Orbital TIG welding entails, you’re in the right place.

Understanding Orbital TIG Welding

Orbital Tungsten Inert Gas (TIG) welding is a specialized form of welding that elevates the traditional TIG process to a new level of precision and control, particularly suited for tubular and pipe welding.

Unlike conventional TIG welding, which relies on the manual skill of a welder, Orbital TIG automates the welding torch’s movement around a fixed workpiece, usually a pipe or tube.

This automation allows for consistent, high-quality welds that are crucial in applications where weld integrity and precision are paramount.

The core principle of Orbital TIG welding remains similar to traditional TIG – using a non-consumable tungsten electrode to create the weld and an inert gas, typically argon, to shield the weld area from atmospheric contamination.

However, Orbital TIG takes this a step further by mechanizing the torch movement, ensuring uniform heat distribution and consistent weld bead formation around the circumference of the workpiece.

Key Components

1. Power Supply: The power supply in Orbital TIG welding is more sophisticated than in standard TIG welding. It not only provides the necessary current for welding but also controls the torch’s movement and welding parameters like speed, arc length, and current. This level of control is crucial for producing consistent, high-quality welds.

2. Welding Head: The welding head is the component that differentiates Orbital TIG from its traditional counterpart. It holds the tungsten electrode and is designed to move around the workpiece. The welding head’s precision movement ensures even distribution of heat and consistent application of the weld pool, leading to uniform weld quality.

3. Wire Feed Mechanism: While not always used in Orbital TIG welding, a wire feed mechanism can be incorporated to add filler material to the weld. This is particularly useful for thicker materials or when additional reinforcement is needed. The wire feed is synchronized with the welding head’s movement, ensuring a consistent addition of filler material throughout the welding process.

Preparing for Orbital TIG Welding

Orbital TIG welding is renowned for its versatility and effectiveness across a wide range of materials. Predominantly, it’s used for welding stainless steel, carbon steel, titanium, Inconel, and Hastelloy, among other alloys.

Each of these materials has unique properties that make them suitable for specific applications, such as stainless steel’s corrosion resistance being ideal for food and pharmaceutical industries, while titanium’s strength and lightweight characteristics suit aerospace and marine applications.

An essential aspect of preparing these materials for Orbital TIG welding is ensuring their cleanliness. Any contaminants, like oils, greases, oxides, or even fingerprints, can compromise the integrity of the weld. Therefore, thorough cleaning of the material surface is crucial.

This often involves mechanical cleaning methods like grinding or brushing, followed by chemical cleaning with solvents to remove any residual contaminants.

Equipment Setup

Setting up your Orbital TIG welding equipment properly is crucial for achieving the best results. Here’s a step-by-step guide to ensure you’re ready to weld:

1. Assemble the Welding Head: Start by securely attaching the welding head to the workpiece or fixture. Ensure it’s properly aligned and the torch is at the correct angle to the weld seam.

2. Install the Tungsten Electrode: Insert the tungsten electrode into the welding head. The electrode type and size should be chosen based on the material and thickness you’re working with. Make sure it’s ground to a point for precise arc control.

3. Connect to the Power Supply: Hook up the welding head to the power supply, ensuring all connections are secure and correct. The power supply settings will vary based on material type and thickness, so refer to your equipment’s manual for specific guidelines.

4. Set Up Shielding Gas: Connect your shielding gas, typically argon, to the welding head. Adjust the flow rate according to the material and application – generally, a higher flow rate is needed for thicker materials.

5. Configure the Welding Parameters: Input the desired welding parameters into the power supply. This includes the current, travel speed, and arc gap. These parameters should be based on the material type and thickness, as well as the specific requirements of the weld.

6. Test Run: Before starting the actual welding, perform a test run. This helps ensure that everything is set up correctly and the welding parameters are appropriately adjusted.

Tips for Optimal Configuration

• Material Thickness: For thicker materials, you may need to increase the current and reduce the travel speed to ensure deep penetration. Conversely, thinner materials require lower current and faster travel speeds to prevent burn-through.
• Material Type: Adjust the arc gap and current based on the material type. For example, titanium requires a tighter arc gap to protect the weld pool from atmospheric contamination.
• Joint Configuration: Consider the joint type and position when setting up the machine. Some configurations may require adjustments to the torch angle or the addition of a filler wire.

The Welding Process

Step-by-Step Welding Procedure

Step	Description	Tips
1. Positioning the Torch	Align the welding head so that the torch is centered over the weld seam. The torch should be at an angle that allows optimal access to the joint.	Ensure the torch is not tilted too much, as this can affect weld quality.
2. Setting the Arc Length	Adjust the arc length, which is the distance between the electrode and the workpiece. This should be set according to the material thickness and type.	A shorter arc length is typically better for thinner materials, while a longer arc may be needed for thicker materials.
3. Initiating the Weld	Start the weld by initiating the arc. This should be done smoothly to prevent any splatter or inconsistencies at the beginning of the weld.	Use a ramp-up feature if available on your power supply to smoothly initiate the arc.
4. Controlling the Speed	Maintain a consistent travel speed. This speed should be set based on the material thickness and the desired weld bead profile.	Monitor the formation of the weld pool and adjust the speed as necessary to ensure even heat distribution.
5. Completing the Weld	Finish the weld by tapering off the current and speed at the end of the joint to prevent crater formation.	Use a ramp-down feature to smoothly conclude the welding process.

Monitoring and Adjusting

Monitoring the Weld Pool:

• Keep a close eye on the weld pool’s size and shape. It should be consistent throughout the weld. If the pool is too small, it may indicate insufficient heat input, whereas a too large pool could suggest too much heat or slow travel speed.

Adjusting Parameters:

• If you notice inconsistencies in the weld pool, adjust the current or travel speed accordingly. For instance, increasing the current can help achieve better penetration in thicker materials, while decreasing the speed can allow more time for the weld pool to form properly in intricate areas.

Common Challenges and Solutions

Challenge	Solution
Inconsistent Weld Bead	Adjust the travel speed and check the torch angle. Ensure the welding head is moving smoothly around the workpiece.
Excessive Spatter	Reduce the current or check the gas flow rate. Ensure the electrode is in good condition and properly shaped.
Porosity in Weld	Increase the shielding gas flow to better protect the weld pool. Also, check for contaminants on the material surface.
Overheating of Material	Increase the travel speed or reduce the current. Ensure adequate cooling time between welds.

Advanced Techniques and Tips

Working with Different Metals

1. Stainless Steel:

• Preparation: Ensure the stainless steel is clean and free from any contaminants. Use a dedicated stainless brush to avoid cross-contamination.
• Heat Control: Stainless steel is prone to warping due to its thermal properties. Use a lower heat input and consistent travel speed to minimize distortion.
• Gas Selection: Use a higher percentage of argon in your shielding gas to ensure a clean, oxide-free weld.

2. Aluminum:

• Cleaning: Aluminum needs to be thoroughly cleaned as it forms an oxide layer rapidly. Use a stainless steel brush and acetone for cleaning.
• Technique: Utilize a higher travel speed due to aluminum’s high thermal conductivity. This prevents heat build-up and reduces the risk of burn-through.
• Filler Material: Choose a filler material that closely matches the base aluminum alloy for better compatibility and weld strength.

3. Titanium:

• Shielding Gas: Titanium requires an inert atmosphere, not just at the weld pool but also around the heated area. Argon is commonly used, and extra care should be taken to shield the back of the weld.
• Heat Control: Control heat input meticulously to prevent overheating, which can cause brittleness in the weld.
• Environment: Weld titanium in a controlled environment to prevent contamination from air or moisture.

Troubleshooting

1. Porosity:

• Cause: Often due to contamination or insufficient shielding gas.
• Solution: Increase gas flow and ensure the material is clean and dry.

2. Cracking:

• Cause: Typically due to rapid cooling or material stress.
• Solution: Preheat the material if necessary and ensure proper welding technique to minimize stress.

3. Distortion:

• Cause: Caused by uneven heat distribution.
• Solution: Use heat sinks or clamps to minimize distortion. Adjust travel speed and heat input to control the temperature throughout the welding process.

Tips to Prevent Defects

• Consistent Shielding Gas Coverage: Ensure the gas adequately covers the weld area to prevent oxidation and contamination.
• Proper Welding Speed: Maintain a steady speed to ensure even heat distribution and penetration.
• Regular Maintenance: Keep equipment, especially the welding head and torch, in good condition. Regularly check and replace worn parts.
• Material Handling: Handle materials with care to avoid introducing contaminants. Store metals in a clean, dry environment.
• Practice and Patience: Orbital TIG welding is a skill that requires practice. Take the time to understand the nuances of each metal and adjust your technique accordingly.

Safety Considerations

Personal Protective Equipment (PPE)

PPE Item	Importance	Specific Recommendations
Welding Helmet	Essential for protecting eyes and face from radiation and sparks.	Choose a helmet with auto-darkening features and appropriate filter shades (typically 10-13 for Orbital TIG welding).
Protective Gloves	Prevents burns and electrical shocks.	Use gloves made from durable, heat-resistant materials like leather, specifically designed for welding.
Welding Jacket and Apron	Protects skin from sparks and spatter.	Select flame-resistant materials. Jackets with leather panels offer additional protection.
Safety Glasses	Protects eyes from debris during grinding or cleaning.	Wear glasses with side shields and appropriate safety ratings.
Ear Protection	Prevents hearing damage in noisy environments.	Use earplugs or earmuffs, especially when working in confined spaces with loud machinery.
Respirator	Protects from inhaling harmful fumes.	Use a respirator when working in environments with poor ventilation or when welding materials that emit hazardous fumes.

Workspace Safety

Safety Aspect	Tips
Ventilation	Ensure good ventilation in the workspace to disperse harmful welding fumes. Install local exhaust ventilation or use portable fume extractors if necessary.
Fire Safety	Keep a fire extinguisher nearby. Remove flammable materials from the welding area and ensure there are no sources of sparks or open flames in the vicinity.
Electrical Safety	Regularly inspect welding equipment for damaged cords or insulation. Always ground the welding equipment properly to prevent electrical shocks.
Clutter-Free Area	Keep the workspace tidy to avoid tripping hazards. Secure all hoses and cables to prevent accidents.
Lighting	Ensure adequate lighting in the welding area for clear visibility, reducing the risk of accidents.
Emergency Procedures	Familiarize yourself with emergency procedures and the locations of emergency exits. Regularly conduct safety drills.

Practice and Skill Development

Practice Projects

Developing your skills in Orbital TIG welding can be both challenging and rewarding. Here are some practical projects that can help you improve your proficiency:

1. Pipe Joints Practice:
   • Project: Welding different types of pipe joints, such as butt joints, socket joints, and T-joints.
   • Skills Developed: This will improve your ability to handle various pipe configurations and orientations, essential for Orbital TIG welding proficiency.
2. Material Variety Welding:
   • Project: Practice welding on different materials like stainless steel, aluminum, and titanium.
   • Skills Developed: This helps you understand the nuances of welding various materials, each with its own characteristics and challenges.
3. Thickness Variation:
   • Project: Welding sheets and pipes of varying thicknesses.
   • Skills Developed: You’ll gain experience in adjusting welding parameters for different material thicknesses, a critical skill in achieving quality welds.
4. Replication of Industrial Applications:
   • Project: Create mock-ups of industry-specific welding tasks, such as welding a section of a pipeline or fabricating a part used in pharmaceutical equipment.
   • Skills Developed: This offers a realistic experience of the challenges you’ll face in actual industrial settings.