The Xiris Blog

Cornelius Sawatzky

Recent Posts

Post Scarf Inspection of Automotive Fuel Line Tubing

Posted by Cornelius Sawatzky on Wednesday, June 14, 2017 @ 04:00 AM

Fuel line tubing is typically manufactured on an ERW welding mill similar to traditional seam welded tubing.  Once the tube has been welded, it moves down the mill for further in-line processing that may include reducing, sizing, annealing and coating processes to meet the customer’s needs.

Fuel line tubing must be perfectly round in order to create a good seal when compression fittings are applied to it. The tube surface must be free from longitudinal scratches, grooves or beads in order to prevent a leak path from developing at the interface point of the fittings.

Immediately after the fuel line tube has been welded and before any further in-line processing is done, the weld bead must be scarfed (the process whereby the weld bead is cut off with a knife).  Unfortunately, the scarfing process can be the primary contributor to creating a leak path on a compression fitting because:

1. Insufficient scarfing can leave a small portion of the weld bead protruding from the     surface of the tube. This may be on either one or both sides of the weld bead where scarfing tool positioning is critical.

June 14 Image 1.jpg

Insufficient Scarfing

2. Excessive scarfing may look perfectly round to the human eye however a non-uniform wall thickness may be lurking below the surface. What is not always apparent and usually only observed during thorough end cut inspection is a thinned portion of the tubing wall that may compromise the integrity of the tube. The reducing process applies enough external force to the tube that the tube may buckle or collapse, causing a deep surface groove.


June 14 Image 2.jpg

Excessive Scarfing

3. A mismatched setup may also be a contributor to a non-uniform wall thickness. The scarfing tool may cut the bead on the outside diameter so that it looks perfectly round to the human eye, disguising the compromised wall thickness below the surface. Sufficient mismatch conditions will most certainly cause the tube to split on end forming later in the fabrication process.

June 14 Image 3.jpgMismatched Defect, Post Scarfing

The Xiris WI2000/3000 Weld Inspection System uses laser-based imaging techniques to continually monitor the scarf zone for any variations in the scarf height, seam mismatch and possible scarf tool wear or chips that may cause a longitudinal line on the tube. By detecting and responding to these conditions proactively, a mill operator is able to reduce the chance of a leak path on the tube and avoid an unplanned stoppage to the mill due to a tube collapse during the reducing process.

For more information on how a Xiris Weld Inspection System can enhance your scarfing processes visit Xiris.com 

Don't miss any of our amazing weld videos! Sign up to receive the 

Weld Video of the Month 

Topics: quality control, Tube and Pipe welding, laser-based monitoring, scarfing, productivity tools, automotive

Xiris Helps Tube Producer Eliminate Weld Problems

Posted by Cornelius Sawatzky on Wednesday, November 16, 2016 @ 10:08 AM

Xiris’ WI2000 Weld Inspection System measures weld bead and formed tube geometry for tube and pipe producers.  Recently, the WI2000 was featured in an article in the Tube and Pipe Journal, where it was identifed as a major reason why Middletown Tube of Ohio, USA was able to improve its tube quality and reduce its scrap rate.

Providing more benefits than was expected, the WI2000 has helped the tube producer find defects with their mill equipment and setup; catching potential defects before they become failures and cause scrap.  As a result, tube mill setups have become a science rather than an art for Middletown.

Read the full article here.

Blog Nov 16.png

For more information on how Xiris Weld Inspection Systems can improve the quality and productivity of your tube and pipe production, visit Xiris.com 

You may also be interested in our Weld Video of the Month 

Topics: quality control, weld inspection, Xiris, welding, Tube and Pipe welding, productivity tools, Middletown Tube

Edge Detection for Weld Monitoring

Posted by Cornelius Sawatzky on Tuesday, June 21, 2016 @ 02:00 AM

With the advent of high dynamic range weld cameras, such as the Xiris XVC-1000, images of welding processes can be made with enormous ranges of brightness.  As a result, it is now possible to monitor and record good quality video of most welding processes using an HDR camera.  With good quality images of the weld pool, arc, and seam, the next logical step is to incorporate image processing into the camera system to extract additional information to help operators better control the welding process.

The Edge Detector tool from Xiris is a powerful edge detection and analysis utility that can detect edges, or areas of rapid contrast change, within a region of interest.  When used with a weld camera, the edge detector can help find the size and position of numerous features in a welding scene such as wire width and length, weld seam gap or center, molten pool boundaries or torch tip edge quality.

Edge_1.png

Figure 1: Edge Detector window

The Edge Detector generates a projection of intensities from a region of interest into a profile, then analyzes the profile to find presence of edges.  Each edge has a series of properties such as edge strength, expected polarity and location that can be used to measure or sort each edge so that objects in the weld environment can be analyzed.  The net result is a new way for fabricators to enhance the monitoring and controlling of their weld processes.

 Conclusion

By incorporating image processing tools such as an Edge Detector into their weld camera systems, machine builders can measure features of their weld processes in a way that has never before been possible.  It is now possible to find edges in an image, such as the weld wire, or seam, that could allow for further monitoring or analysis, or form the foundation for seam tracking or weld pool geometry analysis.

For more information on how Xiris Weld Cameras and the new Edge Detector tool can help monitor your weld processes, visit Xiris.com

Topics: weld video, Xiris, welding, High Dynamic Range, R&D, edge detection

Detecting Slag Build-up on Ferrite Casings in Pipe Mills

Posted by Cornelius Sawatzky on Tuesday, April 26, 2016 @ 02:00 AM

 A major challenge in producing good quality pipe on a welded Pipe Mill is the build-up of slag on the ferrite bundle used inside the pipe. Slag is a mixture of metal oxides and silicon dioxide that is a byproduct of separating the steel from its raw ore.  Ferrite bundles are typically placed inside the pipe to help concentrate the electrical radiation towards the seam to be welded.  During welding, slag can drip down from the molten metal at the edges of parent material, building up deposits on the ferrite bundle casing surface inside the pipe.  The result is a potential reduction in power concentration at the weld point, which could lead to weakened pipe welds.  Known as a “Ferrite breakdown”, it needs to be identified early in the weld process in order to avoid poor welds from making their way down the line or out the door to the customer.

Ferrite_Bundle.pngFerrite Bundle for large Pipe

(courtesy www.piecsa.mx)

 One obvious solution would be to periodically stop the mill and open up the pipe and visually inspect the casing; this of course is not always a feasible or desirable solution.  A better approach to identify changes over time is by monitoring the shape of the weld bead. This can be done by operators who might visually inspect the scarf coming off the tube for signs of change and or abnormalities.  However, as slag could build up on the surface of the ferrite bundle casing which is inside the welded pipe, it is difficult for the operator to notice any slag buildup.

A better solution would be to use a laser based profile measurement system such as the Xiris WI3000.  By using a precise laser with a high speed camera, multiple images of the weld bead and its immediate area can be taken.  The shape of the weld bead can then be automatically analyzed for potential defects.

If there is slag buildup on the surface of the ferrite casing and less power makes it to the seam of the pipe, the top of the weld bead may become flatter or even concave as a result of reduced weld power concentration.  Visually it may appear to the operator as a “pasty” weld and we like to call it a “freeze line” defect.

When monitoring the weld bead using a laser profile of the weld zone complemented with some real time geometrical measurements, the operator can be alerted to the freeze-line condition defect much sooner.  As seen in the picture below taken from the screen of a WI3000, the operator is provided with a magnified view of the weld zone readily visible from afar.  In this view the weld bead is starting to flatten and if it becomes concave, the operator would be alerted before a potential faulty weld is generated.

 

Screenshot.png

Screenshot from the Xiris WI3000 Laser Inspection System

The shape of the weld bead on an ERW pipe mill can provide much information.  In particular, if a laser based profile measurement tool is used, such as the WI3000 from Xiris, early detection of defects such as freeze line can be made.  Such defects often occur as a result of a reduction of power making its way to the weld zone resulting in incomplete heating of the weld bead. By providing early warning of such defects, operators can correct the problem before it becomes a critical failure.

For more information on how WI3000 can help reduce ferrite breakdown in your tube mill, visit Xiris.com

Topics: quality control, weld camera, Laser welding, Xiris, welding, High Dynamic Range, weld pool, productivity, slag buildup

Post-Secondary Schools Increase Trade Resources and Improve Student Experience

Posted by Cornelius Sawatzky on Wednesday, July 02, 2014 @ 04:16 PM

Technical trade schools and welding education programs are not new to post-secondary institutions, but as organizations see an increase in admissions, there is also a noticable increase in demand for equipment. This is not only to appease the quantity of new students, but also to ensure safety and efficiency in the curriculums. The most appealing program to a student will have experienced and knowledgeable professors, interesting and extensive material, as well as modern equipment. However, even with all of these tools there are still some major factors that all of these institutions face:

  • The booths to demonstrate and instruct welding are too small for more than just a few students at a time
  • The instruction area has inadequate space for the number of students registered in the program
  • The welding consumables budget is insufficient and will not cover the cost for new equipment

When instructing such a unique trade, it is important that students not only understand what is being taught, but can see the demonstration. Being able to see and understand what is occurring with a weld tip and arc, as well as the environment around it (weld seam, weld pool, shielding gas, and wire feed) are all essential elements to understanding the welding process. Without a grasp on these elements and factors, there is little that can be retained by the student. This is all based on a visual demonstration that can be hard to provide in many welding institution settings.

As technology and equipment advance, the ability to record lessons and welds adds an immense benefit to both students and instructors. Students can learn more outside of the classroom, as well as retain and digest all of the important elements of the lesson using video playback. This can be provided through the addition of weld cameras.

teach paper resized 600

Not any camera can be placed in such a hostile environment, and expected to function normally. Therefore, more research and development has been contributed to constructing a small, clear, and functional camera that can withstand this environment, and provide the best image quality. Xiris Automation Inc. has created such a camera, called the XVC-O (Xiris View Camera for Open Arc Welding). This allows video recording, clear images, storing/saving capabilities, as well as better classroom visuals for welding programs. This live weld feed can be attached to a simple monitor (as demonstrated above), or even a full size projector, and still provide a clear, comprehensive view of all elements. Xiris has also developed a version for submerged arc welding.

Local colleges, such as Conestoga College, have added this kind of technology to their budding trades programs. As the Government of Canada announced this May, they are investing $2.3 million over the next five years towards Conestoga College’s new Centre for Smart Manufacturing establishment. Already using the XVC-O, these improvements have allowed Conestoga to become an extremely competitive College in the area, and one of the most competitive for the welding trade school industry. Other institutions, such as NAIT (Northern Alberta Institute of Technology) have also added systems to their curriculum and have noticed great improvements. NAIT’s Chair of Welding Programs, Chris Manning says “by displaying the captured welding video on a remote screen, the instructors can vastly improve the learning experience of their students, with improved learning success, which is always the instructor’s goal”.

For more information about how welding cameras can assist welding education please visit www.xiris.com.

 

Topics: quality control, weld camera, weld inspection, Machine Vision, camera placement, field of view, welding instruction, Education, Welding Process, weld video, Xiris, welding, Conestoga College, NAIT

Monitoring Tube and Pipe Production to Find SCARFING Defects

Posted by Cornelius Sawatzky on Tuesday, June 17, 2014 @ 12:53 PM

Recent advancements in machine vision technology have made a new type of inspection able to see defects related to the forming and welding area of a tube or pipe.  The result is improved quality assurance and process control on the production line.  The new type of inspection device is a laser-based triangulation system that measures the outside contour of a tube or pipe in the vicinity of its weld. 

Typically NDT systems are placed at the end of a production as a final check.  However, the laser inspection system can be placed directly after the weld box.  This system can let operators know what is changing in their welding process, allowing them to perform corrective action before significant scrap occurs. This capacity is especially helpful for one of the most common defects found across all types of Tube manufacturing: Tube Scarf defects.

 

The Scarfing Width

In certain situations on ERW/HF tube and pipe production lines, there is not enough space to perform the Non Destructive Inspection (NDI) measurements right after the weld box because the scarf tool (used to remove excessive bead from the tube) is placed directly after the weld box.  In such situations, the measurement process must be made after the scarfing tool, measuring the flat area of the tube where the scarf has occurred. On some production lines, this measurement is essential to identify the shape and profile of the tube, and to understand how it is travelling through its forming process.

Known as the scarf width, this measurement is defined as the length of the “flat” portion of the tube that appears after the weld bead has been removed by scarfing.  Scarf width measurement changes quickly during production, so it is best averaged over a number of inspections in order to make the measurement stable.

 June 17.14 Blog Scarfing resized 600

The Scarf Width, where “w” = the width of the defect.

How the WI2000p System Measures the Scarf Width

Xiris Automation Inc. has developed a non-destructive inspection system called the WI2000p Weld Inspection System. The WI2000p includes a laser line and a camera whose optical axis is offset to the axis of the laser line by an “offset angle”.  The WI2000p creates a visible cross-section of the tube by projecting the laser line on to the tube and capturing an image of the line using the camera.  The resulting image shows a profile of the tube surface as if it were cut in cross section.  If a tube is ideally round, the laser image will represent a section of an ellipse and any anomaly such as a freeze line defect can be mathematically detected. 

The WI2000p bases all of its measurements on the differences between the actual laser profile line seen by the camera, and the ideal mathematical profile based on the tube parameters.  By knowing the position of the actual laser profile, the ideal profile, and the size of the pixels in the image, the WI2000p can detect weld bead profile defects that often escape detection by other quality tools such as Eddy Current testing, or Ultrasonic Testing techniques

 

Conclusion

Overall, laser-based 3D imaging systems, such as the WI2000p from Xiris, offer an excellent measurement option for tube mill owners/operators who want additional, real-time monitoring of weld features. They can be used in a proactive manner, warning operators what is changing in their welding process so that they can perform corrective action before significant scrap occurs And by measuring the outside contour of a weld, laser-based 3D imaging systems can operate on any type of material, regardless of its reflectance or magnetic properties, using a single head to perform the measurement.

Topics: quality control, weld camera, weld inspection, Laser welding, image processing, High Dynamic Range, Tube and Pipe welding, laser-based monitoring, Pipe Cladding, welding defect, scarfing