4 Common Misconceptions About Certified Welding Inspectors

Welder at work

For such an important profession, welding inspection is not well understood. Inspectors save thousands of lives and billions of dollars, yet many companies do not know how to use their skills properly. If you plan to become a certified welding inspector or work with one, don’t make the mistake of thinking that they:

1. Can Judge By Sight

Many underestimate the complexity of welding inspection, assuming that inspectors can find flaws just by looking at the metals. In fact, most metal flaws are far too subtle for the human eye to detect. Inspectors must instead rely on:

  • Magnetic Particle Testing, or the use of magnetic fields to find discontinuities in the metal.
  • Ultrasonic Testing, which involves detecting flaws with acoustics.
  • Other Non-Destructive Methods, including testing with liquid penetrants, radiation, and infrared technology.

Failing to understand the complexity of welding inspection is as harmful for manufacturers as it is for prospective inspectors. Many companies underestimate the task, don’t vet their inspectors properly, and end up with sub-par inspections.

2. Are Lone Wolves

Besides underestimating the complexity of inspection, many companies don’t realize that inspectors cannot stand alone. Testing is only as accurate as the conditions allow it to be, and even the most skilled inspector cannot test properly if the company doesn’t take proper precautions. Cleanliness, for example, is necessary for an accurate test; if the metal is greasy or oily, it will trap magnetic particles, undermining that form of testing. Manufacturers must thus keep their metal products as clean as possible and obey all of their inspector’s other instructions.

3. Can Switch From Job To Job

Not only is welding inspection a highly skilled profession, but the specific skills needed vary from company to company. Many companies create their own tests to certify welders and welding inspectors, which often differ significantly from the standard American Welding Society ones. This can often make it difficult for inspectors to switch to other companies if they don’t like their current jobs. At the same time, it means that certified welding inspectors become invaluable to companies once they are hired, giving them substantial bargaining power. In any dispute, a company is far more likely to accommodate its current inspector than it is to undertake the cost of hiring and training a new one.

4. Only Need Technical Skills

Although inspection is a highly technical job, communication is every bit as important to an inspector’s work. Inspectors must explain to welders and the broader company what flaws they detect, how to fix them, and how to avoid similar problems in the future. This means breaking complex scientific and engineering terms down into language that the uninitiated can understand. It takes great rhetorical skill to do this effectively.
Steel City NDT provides high-quality inspections on all types of metal. We carefully vet each certified welding inspector we hire, making sure everyone has the skills and experience to do the job correctly. For more information, visit our website today.

6 Myths About Hydrostatic Testing

Text appearing behind torn brown envelop - Question marks

Hydrostatic testing is a very important way to ensure that pipelines and other system parts are safe before they are installed. However, there are a lot of myths about this type of testing, and those myths can cause structural problems and put people at risk. Here are six common myths about hydrostatic testing.

During hydrostatic testing, you don’t have to remove gas tubes

Gas tubes should always be removed when doing any kind of testing. Leaving them where they can become damaged is not a good idea. It costs money to fix them, and if they become damaged and that damage isn’t noticed, they can end up being a serious risk to life and limb when the pipes or system finally goes live. By taking the tubes out during hydrostatic testing, you protect the tubes and other components and parts and reduce the risk of future problems.

You can’t test the integrity of a pipeline without hydrostatic testing

There are a lot of different ways to test the integrity of a pipeline, so you don’t have to use hydrostatic testing. It’s one option, and it’s one of the best options, but it’s not an official requirement. Other choices can be considered if there’s a reason the person doing the test would prefer to use a different kind of testing method.

If it passes the hydrostatic test, a visual inspection isn’t necessary

A visual inspection is always necessary. Passing the hydrostatic testing is important, but there should be more than one test or inspection conducted to make sure the welds are right, the pipes are holding, and all the components of the system are in full working order. A visual inspection can uncover things that other inspections or tests may have missed.

You don’t need to test at more than the system’s design pressure

By testing at 1.5 times the pressure the system is designed to hold, any problems can be located more easily. If something is going to fail, you want it to fail during the test, not during use. Using a higher pressure during the test can help ensure that any failures happen before the components are put into actual use.

It isn’t necessary to have all vents open before a test

Opening all the vents removes all the air from the pipes. The air needs to be able to escape fully before the test, so don’t leave vents closed. All the air might get out, but you’ll put a strain on the system that isn’t necessary, and that can be avoided.

You can weld after the test is performed

Welding should be done before the test is carried out, as it may not be safe to weld afterward. Making sure all the welding and other hot work is performed first can provide hydrostatic testing that is much more accurate. Finish any and all welding on the pipe system, and then perform your hydrostatic testing.

 

The Cool But Untold History of Ground Penetrating Radar

Antique Typewriter. Vintage Typewriter Machine Closeup Photo.No one needs to tell you that before you raise a structure, whether it’s a skyscraper or an airplane hangar or a grocery store, you’ve got to know a whole heck of a lot about the ground you’re building it on. Non-destructive testing (NDT) has a solid reputation in the construction field because it allows workers to ascertain that a particular site is stable, firm and safe … or alternatively, not.

One such NDT technology is ground-penetrating radar. You may think the name says it all, but really, there’s a lot you might not know. Here’s a brief untold history of one of the most reliable technologies in the industry.

The Application Was Obvious

You might think that when Christian Hülsmeyer patented radar back in 1904, he might first have spent a lot of time pointing it at the sky. After all phrases such as “flying under the radar” make us assume this device is most often used to locate enemy airplanes (or submarines).

But actually, radar technologies – which use radio waves – were pretty quickly pointed at the ground. As early as 6 years after the patent, Gotthelf Leimbach and Heinrich Löwy patented the first radar technology to locate buried objects.

It’s Not Just for Construction

As it happens, archeologists have also found a wide range of applications for ground penetrating radar as well: Mayan houses and platforms, burial tombs, cellars and graves, and pit dwellings are all among the scientific discoveries made using this technology to make maps of what’s beneath the surface. The military also uses it for detecting underground dangers and to avoid tunnels, among other things.

Not All Ground Is Alike

Unfortunately, you can’t just point a device at the ground and go. Well, you can, but in many cases it works better than others. You probably already know that radar relies on conductivity: it uses a wave, and that means it needs something to travel through. Soil, clay and moist materials don’t present much of a problem, and you can get a clear map.

On the other hand, dry or very sandy soils don’t conduct well. Ditto concrete, granite, cement, or other large, heavy masses. Also, ground penetrating radar works best at ranges between 20 cm to 5 m below ground, which means mapping the secrets of the Earth’s core is best left to other means.

It’s a Relatively New Construction Tool

The applications of ground penetrating radar to construction are so obvious, you might think it has always been used for this purpose, but not so. It wasn’t until 1985 or so that radar systems actually became affordable, and not until sometime in the 90s that comprehensive textbooks and knowledge bases made using them feasible.

Nowadays, ground penetrating radar is a wonderful tool in the NDT kit. Moreover, you don’t have to do it yourself. Instead, you can hire experts like Steel City, NDT, to do the job for you, making your job safer, faster and easier.