WHY ARE INSPECTIONS OF WELDED JOINTS IMPORTANT?

Every day, more and more projects are being developed where metals are the common denominator. For this reason, each project must have a clear understanding of the fundamental factors that ensure its development is carried out in the best possible way.

These variables are aimed at making each project as efficient as possible, thereby avoiding accidents and cost overruns. In welding, procedure qualification is just one link in the quality system chain of a project.

Many people think that by qualifying the procedure and qualifying the welders, the entire management system has been fulfilled, and in many cases they do so just to meet project requirements, forgetting that it is a matter of safety. Below is a compilation of accidents that have occurred in different parts of the world where the common denominator is overconfidence and the omission of nondestructive testing, resulting in irreparable human and economic losses. This article seeks to raise awareness among all people working in the welding and inspection field so that no inspection procedure is omitted and any defect or discontinuity is reported immediately.

Sioux City, Iowa. USA

July 19, 1989. A defect that went undetected in an engine disk was responsible for the United Flight 232 accident. More than 200 human lives were lost.

Pressure vessels.

The failure of a pressure vessel can result in a rapid release of energy. Right photo: Accident that occurred in Flixborough, Great Britain, June 1974, due to the failure of a reactor at a petrochemical plant — 28 people lost their lives and USD $412 million in economic losses.

Lower right photo. Mexico, November 1984. A leak occurred in one of the tanks at an LPG storage facility. 500 human lives were lost and more than USD $100 million in damages.

Bridges.

• Corrosion, weld cracking, and other types of damage can lead to bridge failure.
• The collapse of the Silver Bridge in 1967 in the USA resulted in the loss of 47 human lives.
• Bridges should normally be inspected every two years.

Rails and railcar wheels.

The use of NDT is essential in transportation systems. In countries such as the UK, USA, and Europe, performing NDT at regular intervals is mandatory in order to prevent fatalities.

Transmission pipelines.

• Belgium, 2004
• 40″, 13mm, MAOP = 1189 psi — 16 human lives lost

Many of the hazardous liquid and natural gas transmission lines in the USA are 30 to 50 years old.

• Carlsbad, New Mexico, built in the early 1950s.
• Bellingham was built in 1966.

“Although age alone does not indicate that a pipeline is unsafe, it does make it increasingly important to be able to determine the integrity of these lines.”

These are just some of the many accidents that occur due to the omission of inspection and quality control. Testing before, during, and after the execution of a welding project is essential. By doing so, many human lives can be saved.