Reduce risk and maintain compliance with our specialist risk management services.

We’re proud to be a leading provider of complete life cycle risk management solutions. From ensuring asset safety and legal compliance with our thorough engineering inspections to driving operational efficiency with our specialist non-destructive testing services, (and much more in between), we’re proud of the long-lasting partnerships we have formed with our customers over the last 160 years, based on the value of our solutions.

Reduce risk and maintain compliance with our specialist risk management services.

We're proud to be a leading provider of complete life cycle risk management solutions. From ensuring asset safety and legal compliance with our thorough engineering inspections to driving operational efficiency with our specialist non-destructive testing services, (and much more in between), we’re proud of the long-lasting partnerships we have formed with our customers over the last 160 years, based on the value of our solutions.

Home / Services / Testing / Non-Destructive Testing < / Liquid (Dye) Penetrant Inspection

Liquid Penetrant Inspection

Enhance the reliability and efficiency of your assets and equipment with our industry leading service!

Liquid Penetrant Inspection (LPI) is a Non-destructive Testing (NDT) method that uses dye, and in some situations, a fluorescent penetrant, to find surface-breaking flaws, ensuring the safety, integrity, and long-term reliability of your operations.

Liquid Penetrant Inspection (LPI) is also known as Dye Penetrant Inspection (DPI), Penetrant Testing (PT), or Fluorescent Penetrant Inspection (FPI).

Unveil hidden flaws today

Embrace the power of Liquid (dye) Penetrant Inspection

Our LPI services meticulously scrutinise the surface of your materials, employing a dye penetrant that seeps into even the tiniest cracks and voids, rendering them visible under a developer's illumination.

This transformative process uncovers hidden imperfections that could jeopardise the integrity of your components.

Liquid Penetrant Inspection’s versatility extends far beyond castings and welds. We expertly apply this NDT method to a wide spectrum of non-porous materials, including metals, plastics, composites, and even glass. Whether you’re inspecting intricate parts or large circumference structures, LPI seamlessly adapts to your specific needs.

Get in touch to find out more

A process that unravels the mysteries of material integrity

1. Surface preparation

The surface of the material to be inspected must be clean and free of dirt, grease, and other contaminants. Our team carry this step out to ensure that the dye can properly penetrate the surface and reveal any hidden flaws.

The dye penetrant, a coloured liquid, is applied to the surface of the material, where it will seep into any cracks or flaws in the material.

The excess dye penetrant is removed from the surface of the material to prevent it from obscuring any flaws that may be present.

The developer is applied to the surface of the material. The developer is a powder that will react with the penetrant that has seeped into any cracks or flaws, causing a reaction that causes the dye to become visible, making it easier to identify any flaws. Colour contrast penetrant requires good white light while fluorescents need to be used in darkened conditions with an ultraviolet light (also known as Black Light).

Finally, the surface of the material will then be visually inspected for any flaws. Any cracks or flaws that are present will show as areas of colorant.

Get in touch to speak to an expert

Contact us to learn more about our safe and reliable LPI testing services!

Get in touch today! Get in touch today! Get in touch today!

Discover hidden flaws in your equipment

LPI is a non-destructive testing (NDT) method used to find surface-breaking flaws in non-absorbent materials that can’t be detected by visual inspection alone.

To perform LPI, a dye penetrant is first applied to the surface of the material. The dye penetrant will seep into any surface-breaking flaws, such as cracks or voids. The excess dye penetrant is then removed, and a developer is applied. The developer will cause the dye in any flaws to bleed out, making them visible to the naked eye. Corrective actions can then be taken to rectify any flaws that are found.

A fluorescent penetrant can also be used for more intricate parts, as the fluorescent dye glows under ultraviolet light, making the flaws easier to see.

LPI is a versatile NDT method that can be used to inspect a wide variety of materials and components. It is often used for castings, welds, and Forgings. As LPI is a non-destructive testing method, it does not damage the material being inspected. It is also a relatively inexpensive NDT method and can be performed quickly and easily.

BES Group is a leading provider of NDT services, including LPI. We have a team of experienced and qualified NDT technicians who can perform LPI on a wide variety of materials and components. We also have a state-of-the-art NDT laboratory where we can perform LPI in a controlled environment or we can come to your business.

If you are looking for a reliable and experienced provider of LPI testing services, please contact our team at BES Group today. We would be happy to discuss your needs and provide you with a quote.

Key benefits of Liquid Penetrant Inspection

High sensitivity

LPI possesses an exceptional ability to detect flaws that may be too small or subtle for the naked eye.

Material versatility

Its adaptability extends to a wide range of materials, including metals, plastics, composites, and glass.

Portability

LPI can be performed on-site, facilitating the inspection of large and intricate components.

High sensitivity

LPI possesses an exceptional ability to detect flaws that may be too small or subtle for the naked eye.

Material versatility

Its adaptability extends to a wide range of materials, including metals, plastics, composites, and glass.

Portability

LPI can be performed on-site, facilitating the inspection of large and intricate components.

Hear what our customers have to say

We care about the journey we take our customers on, but it’s not our word you should be taking, see what our customers think of the service we provided!

“

We have been with BES for the past 5 years and don’t plan on switching providers. They are very flexible with their services and are able to bring the best inspectors who can deal with on the ground challenges and build real relationships with clients.

”

Customer

Global Technical Services Manager

“

The BES inspectors are way more technically competent and diligent compared to other providers. BES definitely stands out due to their strong technical competence and strong back office support.

”

Customer

Project Operations Manager

“

BES is a really disruptive force in the market, they are able to provide a variety of necessary services to their customers and none of the other big players are able to provide that breadth of services.

”

Industry competitor

“

The industry requires competence to be demonstrated, typically through UKAS accreditation, which is a prerequisite for many major clients. BES is type A accredited, which is preferred, they can provide highly objective opinions.

”

Customer

Senior Project Manager

FAQs

What types of issues can LPI detect?

What types of materials can be inspected with LPI?

What are the limitations of LPI?

Why choose us

NDT expertise

BES Group has a team of experienced and qualified NDT inspectors who can use our complete suite of NDT techniques to inspect a wide variety of equipment and assets.

Qualified service

Our team are qualified to PCN Level 3 and ASNT NDT, and adhere to the BS EN ISO 9712 standard.

Trusted reliability

BES Group is a trusted and reliable provider of NDT services. We're proud to have a proven track record of providing high-quality services that meet the needs of our customers.