Types of weld inspection methods: Ensuring Safety and Quality

There are multiple methods adopted for **weld inspection**, but only a few are credited to meet the industry standards. Expert players like S.T&W Inspections make use of non-destructive testing techniques to meet the necessary standards for construction, manufacturing, and other critical industrial applications. For more information on the type of weld inspection methods and their application, read this article. Let’s begin.

What is welding inspection?

Welding inspection is the process by which the welded components are checked for safety, strength, and industry standards. It is done to prevent problems that might disrupt smooth operations because of cracks, weak joints, or defects that can lead to failures. Studies have proven that around 80% of structural failures happen when sub-standard welding methods are followed (source).

Types of weld inspection methods:

Visual inspection

As the term suggests, the inspectors check the appearance of the welded components to identify issues like cracks, undercuts, porosity, and more. This method cannot identify the deep-lying internal defects.

Non-Destructive Testing (NDT)

**Non-destructive weld testing** are advanced methods to check the welded parts without causing any damage to them. The types of NDT methods as used by S.T & W Inspections include:

Ultrasonic inspection

In ultrasonic testing for welding method, the ultrasonic sound waves are used at different frequency levels to detect the internal inconsistencies in the component. A team of experts conduct the test across many sectors to assess both in-service and new welds.

Magnetic particle inspection

MPI is used to detect even the slightest cracks. This method is specifically used in industries including rail and structural steel. It includes visible medium and fluorescent Magnetic Particle Inspection methods.

Liquid penetrant testing

This is a highly sensitive method used to detect very fine irregularities. This method can further be categorised as :

• Colour contrast LPI
• Solvent removable LPI
• Fluorescent LPI
• Water washable LPI

District heating NDT

The method is extremely safe, efficient and accurate in detecting the welds of the thin wall pipelines. It is less time-consuming and a more cost-effective method. This method has been specially developed for district heating pipelines in the UK.

**Phased array ultrasonic testing**

PAUT technique generates a detailed image of the inside of the welded component using ultrasonic sound waves. Another benefit of the technique is that it helps to measure the thickness of a component and determine any corrosion inside.

Positive material identification

It is used to identify the exact composition of the component. This method will help test whether the right materials have been used in the component or not.

Destructive testing

A sample of the component to be tested is taken for physical testing. The sample is tested until it fails for its strength and performance. Tensile testing and bend testing are two of its examples.

Dye penetrant testing (PT)

In this method, a liquid dye is applied to the weld surface. This dye then seeps into cracks and reveals the defects when illuminated under UV light.

Final words

Each method has its own set of strengths and shortcomings. Make use of the method that best fits your requirements. The chosen technique should align with your industry standards, too. You can always trust S. T & W Inspections for all your weld inspection and non-destructive testing needs.