Welding Inspections: Examining the Various Types of Welding Inspection

Welding inspections are extremely important for several reasons. Machinery, buildings, pipelines and other essential equipment and materials require welding that must be inspected to ensure safety and reliability.

Welding inspectors can employ various types of welding inspection. With the help of these welding inspection techniques, codes, and standards, welding inspectors can determine if a weld is suitable for its intended purpose.

But, what are these techniques and what types of welding inspection are the most common and reliable?

Let’s take a look.


What is the purpose of welding inspections?
What kind of inspections can be done on a weld?
How many types of welding inspections are there?
What is the most commonly used method of weld inspection?

What is the purpose of inspection in welding?

Welding inspections are important to determine if a weld meets certain codes and standards. In Canada, weld characteristics must meet the standards set out by the Canadian Standards Association (CSA). These regulations help inspectors ensure that machinery and materials can safely and effectively be used.

Certified welding inspectors conduct examinations using a number of tools and techniques. These inspections reveal data related to the size and quality of the weld. Most importantly, they identify any flaws or defects.

Flaws and defects can result in poor performance and safety issues. Therefore, welding inspections also help companies save money by detecting possible failures before they occur. This helps to reduce costs related to incidents, and asset loss, as well as protects employees, the public, and the environment.


Welding inspection being conducted by certified welding inspector

What kind of inspections can be done on a weld?

A weld can be inspected using both destructive and non-destructive techniques.

Destructive techniques physically destroy the weld to determine its viability. Commonly, when an inspector is conducting a destructive weld test, they will break a sample of the weld off to evaluate its strength and other characteristics.

On the other hand, non-destructive testing (NDT) techniques allow a welding inspector to examine the weld and its characteristics without causing harm. These techniques are commonly used by welding inspection companies in Canada.

Buffalo Inspections, for example, is a non-destructive testing company that employs NDT methods when evaluating welds.

How many types of welding inspections are there?

There are five common NDT welding inspection methods used in Canada. These include:

  1. Visual
  2. Radiographic (or X-ray)
  3. Ultrasonic
  4. Magnetic Particle
  5. Liquid Penetrant

Each type of welding inspection offers different advantages and disadvantages. The type of inspection that should be used depends on the asset, as well as the tools and technicians available.

Visual Inspection

Visual inspection, or VT, is the simplest form of NDT welding inspection. In this case, the welding inspector examines the weld visually to determine if any surface flaws are present. Weld size can also be examined to determine any possible issues.

This type of inspection is cost-effective and can be employed while work continues on a structure or material. However, visual welding inspections are limited, as only surface defects can be recognized. As well, in many cases, VT must be conducted throughout a project, especially if more than one layer of material is being deposited.

Often welding inspection companies will begin with a visual inspection to ensure there are no obvious defects.

Radiographic Testing

Radiographic inspection (RT), or X-ray, is a non-destructive testing method that is versatile and commonly used in Canada. This NDT method is employed to evaluate the internal quality of a weld. It can be used to identify internal flaws such as cracks, non-metallic inclusions, burn-through and more.

This inspection method is beneficial because the inspection is recorded on film. This film can then be used for subsequent examination, if necessary. However, several limitations also exist. First and foremost, the quality of the inspection relies on the skills and ability of the inspector and the equipment being used. As well, not all welds are suitable for this type of inspection.

Magnetic Particle Inspection

Magnetic Particle Testing, or MT, detects surface and near-surface flaws.

This NDT method will identify welding defects immediately. As well, sensitivity can be adjusted. This allows for various levels of flaw detection. As a result, welding inspections using MT can identify minor imperfections, including tight cracks and discontinuities.

Unfortunately, Magnetic Particle Testing can only be used on ferromagnetic materials, such as iron and steel. As well, some surfaces, such as those with a thick coat of paint, will not allow for this method of inspection. In addition, like other NDT techniques, a skilled inspector is needed to effectively conduct the inspection and identify any discontinuities.

Liquid Penetrant Testing

Liquid Penetrant Inspection, or PT, is used to identify surface cracks that cannot be detected by the naked eye. This method is common for detecting leaks due to welding flaws.

Unlike Magnetic Particle Inspection, PT can be used to evaluate magnetic and nonmagnetic materials. This method of inspection can help to detect very slight flaws. PT can also detect defects in materials with complex shapes.

However, Liquid Penetrant Inspection is limiting. This is because only surface flaws can be detected. Proper pre and post-inspection cleaning is also required.

Ultrasonic Inspection

Ultrasonic Testing, or UT weld inspection, can identify both internal and surface flaws. As well, UT can identify the location and measurement of a discontinuity.

This method is extremely sensitive, allowing inspectors to detect minor imperfections that other NDT methods will not recognize.

Using phased array technology allows for even more complex and accurate inspections. Phased Array Ultrasonic Testing (PAUT) allows welding inspectors to evaluate a component from multiple angles. This means components with complex geometry can be quickly and accurately inspected. However, this method requires the most skill and experience to properly interpret the results.

What is the most common weld test?

The two most common types of weld tests include Radiographic and Ultrasonic testing. These NDT methods are commonly used because they can detect internal flaws and irregularities. In addition, they can do so without destroying or affecting the integrity of the weld.


Two men from Buffalo Inspections conducting welding inspections

Do you require accurate welding inspections?

Buffalo Inspection Services offers NDT inspection services for CSA Standard W178.1. Our certified technicians inspect buildings, industrial structures, machinery, pipelines, piping, and more using the most advanced and up-to-date technology.

Our CWB certified inspection personnel and CWB level 3 Welding Inspector offer in-depth knowledge and valuable experience. As a result, we provide the most accurate and efficient welding inspections.

Contact Buffalo today to request a quote or schedule an inspection.

Non-Destructive Testing Jobs: A Guide to a Career in NDT

A career in NDT, or non-destructive testing, can be exciting, challenging, and very rewarding. Non-destructive testing jobs are available throughout Canada. NDT technicians are particularly in high demand in cities like Edmonton, Alberta.

There are many career paths, in a wide variety of industries, available in non-destructive testing. Those who are interested in the field can earn certifications for various testing methods at several different levels. With three levels of certification possible for each testing type, there are numerous opportunities for advancement within the NDT industry.

To become an NDT technician in Canada, candidates must complete extensive training, testing, and practical work experience. Technicians who are certified in various NDT methods at a high level will be hired for complex jobs and trusted by organizations to make important decisions about the safety and viability of their assets.

What a non-destructive testing technician does
Types of NDT technicians
NDT certification levels
Non-destructive testing jobs

Non-Destructive Testing Technicians

NDT technicians are trained to inspect and evaluate metals, materials, and other structures for flaws, defects, and damage. NDT inspection specialists use various tools and technology to conduct their testing and may be required to have additional specialized skills, such as mountain climbing training, in some cases. Therefore, non-destructive testing specialists require attention to detail and problem-solving skills, in addition to knowledge of mathematics and science. As well, they must have certain physical attributes including good vision and the ability to differentiate between colours, including shade and brightness.

Many different industries throughout Canada use NDT inspection services to ensure the safety and reliability of their assets. These include oil and gas, pipeline, mining, industrial construction, aircraft and rail transportation, heavy equipment manufacturing, and more. Therefore, NDT technicians can expect to work in many different sectors.

In Canada, a governing body, known as The Natural Resources Canada (NRCan) National Non-Destructive Testing Certification Body (NDTCB), is in charge of a program that certifies all NDT technicians. NRCan was appointed this role by the Canadian General Standards Board (CGSB).

For those wishing to become an NDT technician, the NRCan NDTCB requires certification from a Recognized Training Organizations (RTO). Various RTOs exist throughout the country, with different organizations approved in different provinces. The training organizations recognized in Alberta include:

  • Canadian Institute for Non-destructive Evaluation
  • IDL Inspection Ltd.
  • Keyano College
  • Metalogic Inspection Services Inc.
  • Northern Alberta Institute of Technology
  • Quality Control Council of Canada
  • Southern Alberta Institute of Technology

Types of NDT Technicians

Non-destructive testing is conducted using various methods. Each NDT method requires separate training and certification. Therefore, many different types of NDT technicians exist. A single technician may have more than one certification. That is to say, they can conduct non-destructive testing jobs using various methods. In addition, technicians can be certified at various levels (Level 1, Level 2, and Level 3). Higher levels indicate more advanced skills and additional responsibilities.


In many cases, technicians will begin their career in NDT as a CEDO, conducting radiation testing. A CEDO, or Certified Exposure Device Operator, is certified to work with radiation. In Canada, all CEDOs must be certified by the Canadian Nuclear Safety Commission (CNSC) and only a CEDO can legally perform gamma radiography and operate an exposure device. To become a CEDO, a 40-hour CEDO (Certified Exposure Device Operator) course is required in addition to work experience and testing. A CEDO must have basic math skills and must be able to use computational operations.

The job of a CEDO is to operate industrial gamma radiography exposure devices, in order to test various assets. CEDOs must be able to safely handle and operate these devices, as well as radiation detection and monitoring equipment.

Ultrasonic Technician

Ultrasonic technicians, or UT technicians, are trained to use the ultrasonic testing method. UT technicians use ultrasonic transducers to send high-frequency sound waves into a material to detect flaws and defects inside. Subsequently, the UT technician evaluates the provided graph to determine the possible depth, size, nature and orientation of a flaw or defect. This NDT method can also determine the thickness of the material.

Radiography Technician

A radiography technician, or RT technician, employs technology using x-rays or gamma rays to evaluate the internal soundness of a material. The technician must be able to interpret the resulting output of the test to determine if any flaws or defects are present in the material.

Additional Types of NDT Technicians

There are many other types of NDT technicians – one for every NDT method.

Other NDT technician types include:

  • ET (Eddy-current or Electromagnetic Testing) technicians
  • MP (Magnetic Particle Testing) technicians
  • VT (Visual Testing) technicians
  • PT (Liquid Penetrant Testing) technicians

In order to become a technician for a particular NDT method, applicants must complete training at an RTO. After that, NDT trainees must complete practical work experience with an NDT company. Following this work experience, the NDT trainee must pass the NRCan practical exam.

Levels of Certification

For each type of NDT certification, there are three levels of qualification. Each level allows the technician to offer more advanced services. To achieve a particular level of certification, technicians must obtain industry-specific work experience, as well as complete written and practical examinations.

Level 1 ET, RT and UT technicians must complete a minimum of three months of experience. Level 2 certification requires nine months of work experience and for Level 3 eighteen months is necessary. For MT, PT and VT technicians, Level 1 certification requires a minimum of one month of work experience and Level 2 certification requires three months. Finally, to achieve Level 3 certification a technician must complete twelve months of work experience.

The higher the level of certification, the more responsibility and the more complex evaluations a technician can complete. In fact, the supplementary knowledge that is necessary for a Level 3 certification requires additional experience above and beyond that of any single testing method. A combination of education, training and experience provides this knowledge. For a technician to be awarded Level 3 certification, a record of this additional experience must be presented to the certification body in the form of a CV (curriculum vitae).

Technicians at different levels will have different capabilities and responsibilities and will be able to perform different non-destructive testing jobs. These include:

Level 1 

  • Perform specific calibrations
  • Implement a specific NDT method (only on certain components)
  • Conduct evaluations to determine if the component is acceptable or should be rejected
  • Level 1 technicians require supervision by a higher level tester

Level 2 

  • Posses the same capabilities as Level 1 technicians
  • Set up and calibrate equipment
  • Conduct NDT testing and evaluation in accordance with applicable codes, standards, and specifications
  • Interpret and document the results of the inspection
  • Act as a supervisor for lower level technicians
  • Provide on the job training for Level 1 technicians

Level 3 

  • Posses the same abilities as Level 2 technicians
  • Establish techniques and procedures
  • Interpret codes, standards, and specifications
  • Determine which NDT methods and techniques to use
  • Possess knowledge of materials, fabrication and product technology
  • Train and test Level 1 and Level 2 technicians
  • May be in management positions or become consultants

Non-Destructive Testing Jobs – Employment in the NDT Industry   

The more NDT methods you are certified to conduct, and the higher the level of certification you have, the more non-destructive testing jobs you’ll be qualified for. As well, a higher level of certification results in higher pay. The opinions and decisions of high-level technicians are also viewed as more reliable than technicians with lower-level certifications.

NDT technicians often make judgements that can have significant safety and financial consequences. Therefore, they must be confident in their work and the results they are providing. Technicians can confidently perform more complex jobs and evaluations when they have a higher level of certification.

Looking for NDT jobs in Canada? Buffalo Inspection Services is Western Canada’s largest and most wide-reaching non-union provider of non-destructive testing services. Buffalo is looking for experienced technicians to join their family of professionals.

Find a career in NDT that is a fit for you! Check out Buffalo’s job listings – NDT Jobs

NDT Inspection Technology: What’s New and Leading-Edge in 2020

NDT inspection technology, including training and tools, is continuously evolving.

With changes in government regulations, innovations in technology and the ever-changing needs of industries requiring surface and subsurface analysis, non-destructive testing continues to evolve to ensure the safety, productivity, and integrity of materials, products, and structures.

Interested in knowing more about what’s new and leading-edge in non-destructive testing (NDT)? This article will cover:

Why NDT is important
The advantages of NDT
What’s new in NDT training
What’s new in NDT technology
Pipeline inspection improvements

Why NDT is important

Non-destructive testing is vital for the timely detection of faults in products, materials, and equipment. If left undetected, defects and flaws can result in expensive and premature repairs or replacements. Unplanned shutdowns and failures can also result and have devastating health, safety, and economic impacts.

For pipelines, oil and gas, mining, lifting and industrial construction equipment, and tubing, NDT functions as quality assurance, ensuring the reliability and expected lifetime of equipment and materials is upheld.

Regular testing allows engineers to determine the current lifecycle stage of an asset and to proactively plan maintenance, repairs, or replacements. Regular inspections also ensure that catastrophic failures of your business/operational assets do not occur, potentially resulting in lengthy and costly downtime. Besides, routine testing ensures adherence to government regulations and standards, as well as the health and safety of your workforce and the environment.

Overall, NDT:

  • Prevents accidents
  • Reduces repair and replacement costs
  • Improves reliability of assets
  • Ensures adherence to regulations and policies

What are the advantages of NDT?

Non-destructive testing is ideal because it allows for the inspection of equipment, materials, and structures without the need to worry about downtime or damage.

NDT can save time and money by identifying problems early – before expensive repairs or replacements are needed.

What’s new in non-destructive testing

Advancements in technology and changes to government regulations and policies are continuously driving innovation in non-destructive testing. These changes affect all aspects of NDT, including training, inspection, and technology. The result – new and innovative methods and strategies.

NDT has come a long way since its origins. Simple VT has now evolved with the digital world, resulting in digital outputs, including 3D imaging and cloud connectivity that allows for remote testing and analysis.

NDT Training

NDT inspection technology and its applications are continuously improving and evolving. Inspection technology, equipment, and the services offered by inspection providers are ever-changing, including advancements in training and techniques.

Buffalo Inspection Services, for instance, recently implemented a Personal Certification in Non-Destructive Testing (PCN) course using Gekko and Mantis technology. This training is revolutionary, making Buffalo the first NDT company in North America to host PCN Certification on Gekko PAUT technology and the only non-union NDT inspection services provider in Western Canada with qualified PCN technicians.

NDT Inspection Technology

Advancements in technology drive change in non-destructive testing. As a result, hardware and software enhancements are continuously developed to improve testing and analysis.

Below are some of the most recent advancements that have been made in NDT technology:


Buffalo NDT Inspectors uses the M2M Gekko for PAUT inspections.

The M2M Gekko is one of the most advanced and reliable options for Total Focusing Method (TFM) testing. The only unit that supports a 3-axis encoder for TFM, the Gekko is also the first system able to produce matrix arrays and perform TFM in real-time.

As the most versatile and advanced PAUT field unit, the Gekko can cover a wide range of inspections, and, recently, a new generation of the Gekko was released, with various ground-breaking advancements introduced.

Improvements to the new generation of the Gekko include:

  • Hardware – increased speed and channel sensitivity, longer battery life (up to 6 hours), improved touchscreen functionality (e.g. touchscreen can be used with gloves)
  • Data management – new USB 3.0 connector for rapid file transfer and wireless data or screen sharing, IP68 LEMO encoder connector for compatibility with most scanners
  • Software – the release of new Capture 3.1 software

Capture 3.1 software

The release of Capture 3.1 has brought many improvements to ergonomy, analysis, and TFM tools and options. The new advanced analysis tools offered by Capture 3.1 improve productivity and increase the quality of research and reporting, resulting in more efficient and reliable testing.

The new tools added to Capture 3.1 include:

  • Auto-sizing – for a quick analysis of whether an indication is critical
  • C-scan stitching – for inspections that require more than one file
  • Full 3D exporting
  • Improved indicators


The Total Focusing Method has come a long way since its inception. In 2013, portable TMF revolutionized non-destructive testing. Since then, TMF has seen significant changes to scan speed, the number of TFM options available on the market, and to code. These advancements have allowed TMF to remain one of the best and most reliable techniques for NDT.

  • TMF options on the market
    2013 – 1 TFM option
    2020 – more than 10 TFM options
  • Scan speed
    2013 – ¼ inch per second
    2020 – more than 4 inches per second
  • Code
    2013 – No TFM code
    2020 – Code-compliant

Along with the recent release of Capture 3.1 software, a new TFM method called Plane Wave Imaging (PWI) has also been introduced.

Plane Wave Imaging

PWI, introduced by Eddyfi Technologies, is a new data acquisition technique for TFM. This technique is conducted by first firing all the elements of the array concurrently on several different angles, with elementary signals received on all of the elements. After this initial process, a typical TFM is performed. The final result is a matrix containing M x N (number of angles x number of elements) elementary A-scans.

PWI - Plane Wave Imaging demonstration for NDT Inspections

The advantages of this new method include:

  • Improved productivity – PWI is able to maintain the spatial resolution offered by other TFM methods (e.g. FMC) while increasing scanning speed.
  • Increased sensitivity – depending on the number of angles used, PWI can offer an increase in sensitivity, resulting in the detection of smaller indications.

Pipeline inspection improvements

These new and leading-edge advancements in NDT allow for regular, comprehensive, accurate, and economical testing. The efficient and effective testing provided by a combination of this state-of-the-art technology ensures the safety and utility of large pipelines like the Transmountain.

Combining PAUT / TOFD and conventional UT with advancements like TFM, the Gekko is particularly useful for pipeline inspection in Alberta.

Radiography (x-ray inspection) and UT are commonly used; however, Phased Array Ultrasonic Testing (PAUT) offers several advantages for pipeline inspection. These advantages include NO:

  • Radiation
  • Risk
  • Additional licensing necessary

With the ability to detect manufacturing flaws, corrosion, cracking, erosion, parent metal flaws, and more in pipelines, all while in-service, regular non-destructive testing ensures cost efficiency, environmental and public safety, and reliable, long-term performance.

Want to discuss NDT pipeline inspection for your company? Contact Buffalo today.