The Xiris Blog

Cameron Serles

Recent Posts

Inspecting Metal Sheath on High Voltage Cables

Posted by Cameron Serles on Wednesday, February 20, 2019 @ 11:00 AM

High Voltage Cable is a multi-layer cable used for running high voltages underground or underwater.  The integrity of the cable is very important – the insulation of the cable must not deteriorate due to the high voltage power being transmitted.

Often a high-voltage cable will have a metallic shield layered over the insulation, connected to the ground and designed to equalize the dielectric stress on the insulation layer.  This metallic shield is effectively a welded tube, wrapped around the conducting cores and insulating layers of the cable and welded together as the cable is made.

 

Various High Voltage Cable Samples (courtesy: KEI Industries)

 

If the fabrication process of forming and welding the metal sheath tube is not done properly, the cable may fail its final quality specification and may require to be destroyed, a very costly prospect for the manufacturer. Using a weld inspection system such as the WI2000 system from Xiris, measurements can be made on the production line of the final welded sheath of various attributes such as Mismatch, weld Bead Height and Freezeline to help determine if the metal sheath tube is being welded correctly.

If any of those measurements begin to drift out of tolerance, an operator can be alerted to make adjustments in the input parameters to bring the process back in control avoiding any scrap production.  The result is a better quality welded sheath tube on the cable that has a better chance of meeting the final end user’s specifications.

Better Images. Better Decisions. Better Process Control.

Follow Xiris on social media for regular updates and welding videos!

Instagram LinkedIn FacebookTwitter

Topics: quality control, weld inspection, Tube and Pipe welding, manufacturing, tube, WI-2000p, weld camera system, consistent

Triggering Weld Cameras from a MIG Process

Posted by Cameron Serles on Thursday, February 07, 2019 @ 11:00 AM

MIG processes, particularly short circuit MIG, will generate a huge range in brightness during their metal transfer cycle:  when the arc is extinguished as the wire makes contact with the parent material prior to expulsion, the image can be quite dark. However, after an explusion occurs and the arc is re-established, the image may be very bright as the arc intensifies to its maximum.

Using a camera to acquire images of a MIG weld process in free running mode can be problematic when the amount of light present in the image varies considerably. The variation in light is based on when during the metal transfer process the image exposure takes place: when the arc is extinguished, the image will be dark; when there is a full arc, there will be a bright image. However, if the camera acquisition is triggered by an electrical pulse generated by the camera power supply, the result will be a consistent image of the weld process that is repeatable because it is at the same point of the weld cycle.

Short Circuiting Arc Metal Transfer

(courtesy ESAB Group, Inc.)

A few words about how Short Circuit MIG and certain other kinds of MIG welding function:

  • Wire is fed continuously and makes contact with the workpiece to complete the electrical circuit.
  • At the point of contact, a short circuit occurs, resulting in a huge spike of current moving through the wire between the torch and the workpiece.
  • At point of wire contacting the workpiece, arc gets extinguished.
  • Segment of wire rapidly vaporizes under high current and an arc gets re-established.
  • Current falls as there is no short circuit.
  • Process repeats.

In a constant voltage welding power supply, the current being fed to the torch can rise and fall based on the metal transfer process. When there is a gap between the wire and the workpiece, the conducting current is low, and increases as the wire begins to touch the workpiece and create a short circuit. Then, once the wire tip explodes, the current falls as there is no conducting circuit. The plot of the current levels look something like this:

 Current vs Time

(courtesy ESAB Group, Inc.)

While capturing the welding process to see certain features, it is sometimes interesting to only take images at a certain point in the metal transfer cycle. Rather than using a weld camera in free running mode where image acquisition is based on the clock cycles inside the camera, an efficient alternative is to use an external trigger that is based on the current levels present in the welding power supply.  If a circuit can be designed to generate a trigger signal based on the rising edge of the current level, then the trigger could be used to initiate image acquisition, resulting in video with an increased consistentency in brightness and quality because each frame will be acquired at precisely the same point in the metal transfer process. 

Further enhancement to the performance of the imaging process is possible by tweaking exactly when the images are acquired through adding a delay.  A delay can be added after the trigger signal is generated so that the exact imaging characteristic can be seen.

For example, imagine wanting to see only images of the metal transfer process after the weld arc is extinguished.  To do this, a trigger signal should be generated based on the current pulses coming from the weld power supply.  It may not be possible to receive the trigger at the ideal point in the metal transfer process, so a programmable delay can be added to make sure that the image acquisition occurs at exactly the right point.

With Triggering:

MIG Welding Process Triggered from Rising Edge of Power Supply's Current PulseMIG Welding Process

Successive Snapshots of a MIG Welding Process Triggered from the Rising Edge of Welding Power Supply’s Current Pulse

The above two successive images show a MiG process at roughly the same point of the metal transfer process over different cycles of the metal transfer.  In this case, the imaging was tuned to see exactly what the viewer wanted to see: the melt pool fully visible with the welding arc present.

In Summary

Imaging a MIG welding process can be fairly difficult if using a weld camera in free running mode.  However, if a circuit can be designed to clamp on the rising edge of the current pulse, it can provide an excellent trigger to use to acquire consistent images at similar points in the metal transfer cycle.  The result is much more uniform images with similar brightness levels, allowing for better analysis and increased efficiency of the welding process. 

Better Images. Better Decisions. Better Process Control.

Follow Xiris on social media for regular updates and welding videos!

Instagram LinkedIn FacebookTwitter

Topics: quality control, image processing, HDR, mig welding, reduced costs, weld camera system, consistent, MIG process

Using Weld Cameras to Enable a Continuous Coil Joining Process

Posted by Cameron Serles on Thursday, January 10, 2019 @ 01:00 PM

Xiris’ High Dynamic Range (HDR) welding cameras can be used in a multitude of ways, some of which our customers have discovered on their own.

For example, a manufacturer of thick-walled steel pipe recently figured out how to use our cameras in a way that has greatly improved the efficiency of their coil joining process.

Operators only have about 10 minutes to end-sheer, mate, and weld coils during the semi-automatic front-end part of the process. The cost of coil joint failure is high, so the manufacturer would stop the tube mill to check on the integrity of the coil joint before continuing.

Even though the stoppage prevented more-costly failures, it had its own cost. What our customer needed was a way to adequately monitor the end joining in the infeed buffer of the pipe mill without having to stop the process to assure correct coil matching.

They knew the capabilities of our cameras to enable real-time remote monitoring of weld processes with greater visibility than ever before possible. So they developed a plan to use Xiris XVC-110e50 cameras to monitor the coil joining during the front end of the process. This monitoring eliminates the need for routine stoppages.

This solution also keeps operators safer. Coil joining is performed using a MIG welding torch mounted onto a linear track with dual-axis torch position. Previously, operators had to be close enough to the torch to see what was happening with the weld. With the Xiris HDR cameras, they have a clear view of the coil joining process from a safe remote location.

With their creative use of our HDR camera technology, this manufacturer was able to significantly reduce the time and cost of coil joining, while increasing consistency.

For a video of the coil joining process taken by the XVC-1100e50 camera, please view the video below

Coil Joining Video 

Better Images. Better Decisions. Better Process Control.

Follow Xiris on social media for regular updates and welding videos!

Instagram LinkedIn FacebookTwitter

Topics: quality control, tube, reduced costs, weld camera system, coil joining, tube mill

How to Detect Scarf Tool Wear on a Tube Mill

Posted by Cameron Serles on Thursday, December 13, 2018 @ 11:00 AM

During tube production, immediately after the tube has been welded and before any further in-line processing is done, the weld bead must be scarfed off the tube. Scarfing is the process whereby the weld bead is cut off with a knife, or scarfing tool.  Unfortunately, if the scarfing tool is not done properly, the tube may not meet end user customer specifications because of a rough surface left behind by the scarf tool.  The result can be the primary contributor to creating a leak path on a compression fitting.

Using a surface profiling tool such as the Xiris WI2000, the scarf defect measurement can be used to detect how well the scarfing tool is cutting the weld bead and indicate the amount of scarf tool wear. 

Scarf tool wear describes the gradual failure condition of a scarf cutting tool on a tube mill as a result of ongoing use.  It can occur either as flank wear in which the portion of the scarf tool in contact with the welded tube erodes over time sometimes causing a ridge to be left behind in the scarf zone; or as crater wear, in which contact with chips of weld bead erodes the rake face of the tool causing an uneven cut surface; or a cluster of weld bead material building up on the face of the tool causing it to dredge a groove in the scarf zone. These conditions are somewhat normal for tool wear, and they do not seriously degrade the use of the scarf tool until it becomes serious enough to cause a scarf tool cutting edge failure that may be a concern for a potential leak path for the tube in its final use.

The scarf defect measurement on the WI2000 looks for any significant deviations in surface height above or below the ideal scarf surface.  The Scarf Defect will detect the absolute value of the largest defect on the scarf surface.  Any significant amount of scarf tool wear could reduce the specifications and performance of the final tube, especially for some automotive applications where tight assembly requirements or a smooth, scratch free surface is required.

Scarf Defect_2017-01

The Definition of a Scarf Tool Wear: The scarf plane can be defined as the straight line drawn between the left and right scarf edges.  Any detected features above or below the scarf plane, are measured as a scarf defect.  The actual amount of wear is defined as the distance from the scarf plane measured perpendicularly to the scarf plane.

If you have any questions about our profile inspections for tube and pipe, please feel free to contact us. 

 

Better Images. Better Decisions. Better Process Control.

Follow Xiris on social media for regular updates and welding videos!

Instagram LinkedIn FacebookTwitter

Topics: quality control, Tube and Pipe welding, bead height, scarfing, pipe, tube, defects, WI-2000p, tubedefects, tube mill

Detecting Bead Ripple During Tube Manufacturing

Posted by Cameron Serles on Friday, October 05, 2018 @ 11:45 AM

Lighter wall mild steel pipe production requires bead height monitoring for bead ripple. Bead ripple is a condition sometimes associated with a weld process that is too hot and may result in longitudinal weld cracks.  Bead ripples appear along the length of the weld bead as undulations with measurable differences in height by as much as 1/8” (3 mm).  Often the height of the bead ripple on a welded pipe is a function of the heat that has gone into the weld process:  the higher the heat, the greater the height of the bead ripple. In most applications, a weld bead should have a smooth, consistent height as an indicator of a stable weld process.

Bead Ripple1An image of a weld bead with bead ripple

In some applications, a weld bead ripple can be desired, such as in certain coated steel products. This ensures that all contaminants from the area of the weld have been squeezed out, preventing potential inclusions from occurring in the weld bead, which would result in compromised weld quality.

By measuring the bead height on a weld bead over a period of time using a laser based triangulation system , an indication of the smoothness of the weld bead can be made.  By calculating ongoing historical statistics of the head height (e.g. min/max, average, standard deviation), an indication of smoothness of the weld bead or bead ripple can be made.  Tolerances of the amount of smoothness or ripple can be set to match the process and when exceeded, an alarm can be set.

Bead Ripple Detection1 Measuring the weld bead height over successive images can detect bead ripple over time

Topics: quality control, Tube and Pipe welding, bead height, tube, productivity tools, tubedefects, tube mill

Using High Dynamic Range Cameras for Slip-Ring Applications

Posted by Cameron Serles on Thursday, August 16, 2018 @ 12:00 PM

If you use slip rings and rotating torches in cladding, there now is a way that you can see the welding process much more clearly than ever before.

Xiris has successfully tested our XVC-1000 and XVC-1000e weld cameras on rotating welding machines using slip rings—and the cameras work perfectly!  Unlike other cameras with electrical noise interferences, the Xiris Weld Cameras are not affected by the electrical noise and interferences common with running video over a slip ring.

Even Over a Slip Ring Connection, Xiris Weld Camera Maintains a Noise Free Image

Slip rings are electromechanical devices that are designed to pass electrical signals from a rotary source (such as a weld camera mounted next to one or more torches that rotate around the inside of a part) to a stationary receiver (such as a computer which receives the video data from the cameras). They are devices that allow for the transmission of an electrical signal and power.  By employing a metal brush that rubs against a rotating metal ring, the video signal coming from the camera travels through the connection, avoiding the use of solid cables that could potentially twist indefinitely until damaged.

Weld cameras are making their way into a variety of cladding operations.  However, it is very difficult to monitor cladding on the inside of the pipe, especially when the pipe stays stationary and the torch rotates.  This can be a problem for a standard connection: as the torch rotates continuously, cables cannot withstand very many rotations before they break.  Therefore, the use of slip rings would be a natural solution.  However, slip rings typically are used for motor signals and power, applications that are a little more tolerant of electrical noise than video signals.  Typical industrial cameras haven’t worked well with slip rings because their analog signals are not resistant to electrical noise.

The problem is that cladding is typically done using a TIG welding process, which is notorious for generating lots of electrical noise that can kill standard electronics due to its high-frequency starts.

But the Xiris weld cameras don’t die or short-circuit from high-frequency welding noise, even with a slip ring.  Our cameras and the welding machine keep working together when used with a slip ring—allowing operators to remotely see high dynamic range (HDR) images of their cladding process, in real time, on a computer screen, remotely.  The Xiris weld cameras with HDR capability permit operators to see both the super-bright weld arc and its dark surrounding background, with no need to stop the process.

We’ve tested our HDR weld cameras on slip-ring applications numerous times, and the advanced electronics in the cameras have repeatedly been up to the task. We’d be glad to demonstrate on your set-up.

This is new technology, but it’s ready now to improve the efficiency of your rotating-torch cladding.

Topics: Pipe Cladding, pipe, TIG, Slip Ring, weld camera system, cladding, tig torch, TIG welding

Latest Posts

Follow Me