Fluorescent Penetrant Inspection - FPI (Liquid Penetrant Testing)

Fluorescent Penetrant Inspection (FPI), also known as Liquid Penetrant Testing, stands out as a highly efficient technique for uncovering surface-breaking flaws, cracks, and defects that might otherwise escape detection. Employed widely across diverse industries such as aerospace, automotive, medical, and power generation, this non-destructive testing (NDT) method begins with meticulous cleaning of the object's surface, followed by the application of a fluorescent dye. The dye seeps into any existing cracks or defects, and, after a designated duration, excess dye is removed, leaving the flaw highlighted in vivid, contrasting colors. This process facilitates easy identification of flaws that might be challenging to discern with the naked eye.

In the aerospace sector, FPI plays a pivotal role in ensuring the safety and reliability of aircraft components. Throughout the manufacturing process, it is utilized to assess the quality of raw materials like sheet metal, forgings, and castings before their assembly into larger structures. Additionally, in-service aircraft undergo FPI inspections to detect signs of wear, stress, or other types of damage. In the medical industry, FPI is crucial for identifying defects in components such as medical implants, prosthetics, and surgical instruments, ensuring their safety and reliability for use in medical procedures. In conjunction with FPI, liquid penetrant testing (LPT) encompasses other NDT techniques like water-washable penetrant testing and solvent-removable penetrant testing, employing various penetrants and cleaning methods to identify surface flaws.

FPI Solutions for Manufacturing and MRO

Our systems are meticulously designed to comply with the ASTM E1417 FPI standard, commonly employed in both the aerospace and medical sectors. Kemet offers a comprehensive array of standardized systems, providing the flexibility to integrate automated and manual operations seamlessly. This approach enables streamlined and sustainable non-destructive testing (NDT) inspections, with optional features like integrated waste water handling and extraction systems resulting in substantial cost savings on process chemicals, labor, and energy consumption.

A reliable provider of fully automated systems for inspecting critical airframe components, turbine blades, and medical implants, as well as smaller manual systems for less critical parts. A well-thought-out combination of automation and manual handling significantly reduces labor requirements, while an adjustable layout ensures a small footprint. These FPI systems are durable, safe, ergonomic, and user-friendly.

Kemet offers a range of systems tailored to diverse inspection needs. From flexible manual roll track spray lines with a small footprint to fully automated roll conveyor immersion lines suitable for high-capacity mass production, including dipping penetrant application, "Dust Storm" developer chamber, and integrated pre- and post-wash. Kemet also provides additional options such as material handling, batch traceability via data log, fully automated penetrant and developer spray, basket rotation, basket trolleys, and automatic loading/unloading conveyors.

Automated FPI Line

The automated FPI line ensures a secure and high-capacity process, requiring minimal operator intervention. The operator interface is user-friendly, facilitating data collection for each batch to ensure stringent quality control and traceability. The system incorporates a buffering infeed conveyor, and various conveyor sizes can be accommodated upon request. Precision cleaning is achieved through pre-cleaning with ultrasonic technology, featuring an automatic tuning function. The electrostatic penetrant spray is applied automatically, with carrier rotation and PLC-controlled contact time. Water wash, facilitated by dedicated spray nozzles, efficiently removes penetrant residues, redirecting them to a separate storage tank. Emulsifier treatment, under PLC-controlled time constraints, further enhances the process. The automated electrostatic developer spray, coupled with carrier rotation and PLC-controlled contact time, contributes to the system's efficiency. Notably, the carriers are versatile, capable of securely holding parts of varying sizes and shapes.

FPI solution concepts

The manual roll track spray line is well-suited for examining wheel and brake components. Its flexibility and compact design make it an ideal choice, accommodating various spatial constraints. Additionally, the system offers versatility in application methods, allowing users to choose between optional dip or electrostatic spray techniques based on their specific inspection requirements.

The roll conveyor immersion line is a highly efficient and automated system designed for mass production. This advanced setup streamlines the inspection process, employing dipping for the application of penetrant. To enhance the development stage, the system features a "Dust Storm" type developer chamber, contributing to the overall effectiveness of the operation.

The manual chain hoist line is engineered for increased throughput while maintaining a minimal footprint. This efficient setup is particularly well-suited for applications requiring a double Fluorescent Penetrant Inspection (FPI) line, specifically tailored for turbofan Maintenance, Repair, and Overhaul (MRO) processes.

The automated line presents a seamlessly integrated process, incorporating both pre and post wash stages. This advanced system is equipped with automated process control and efficient material handling mechanisms, ensuring a streamlined and effective operation. Additionally, it provides batch traceability through a comprehensive data log, allowing for meticulous monitoring and management of the entire production or inspection process.

The booth line is characterized by a manual monorail system specifically designed for the inspection of sizable components, such as aero-structures. This setup provides an efficient and controlled environment for the examination of large parts, ensuring a meticulous and thorough inspection process.

Key features and benefits

The strategic integration of automation and manual handling in our system offers significant labor cost savings, exemplifying an intelligent approach to efficiency. With a focus on traceability and reliability, our solution ensures meticulous inspection processes. The adjustable layout not only contributes to a small footprint but also enhances adaptability to various operational spaces. Furthermore, our system boasts low consumption of process chemicals, resulting in cost-effective operations. With durability and safety at the forefront, coupled with an ergonomic and user-friendly design, our solution aims to optimize performance while maintaining a commitment to efficiency and excellence.

Optional features include

  • Fully automated penetrant and developer spray
  • Basket rotation
  • Upgraded ventilation systems
  • Integrated Pre-cleaning and cleaning after FPI processes
  • Basket trolleys and automatic loading/unloading conveyors

Main applications

  • Engine parts
  • Aerostructures
  • Wheel hubs
  • Brake parts
  • Landing gear
  • Automotive parts

Fluorescent Penetrant Inspection machine

Inquiries about Fluorescent and Liquid Penetrant Testing

Fluorescent Penetrant Inspection vs Magnetic Particle

Fluorescent Penetrant Inspection (FPI) and Magnetic Particle Inspection (MPI) represent distinct non-destructive testing methods employed for identifying surface and slightly subsurface discontinuities in metallic materials. Their differentiation lies in the approach to detecting these discontinuities.

Magnetic Particle Inspection (MPI) involves applying a magnetic field to the inspected part. Ferromagnetic particles are subsequently applied to the surface, becoming magnetized due to the applied magnetic field. Any discontinuities in the material cause a leakage of magnetic flux, attracting the particles and forming an indication. This technique is predominantly utilized to detect surface and subsurface discontinuities in ferromagnetic materials, such as cracks, laps, seams, and porosity.

What does Fluorescent Penetrant Inspection detect

Fluorescent Penetrant Inspection detects surface-breaking cracks and discontinuities open to the material's surface. Applicable to various materials, including metals, plastics, ceramics, and composites, FPI is commonly employed in aerospace, automotive, and manufacturing industries to ensure critical component quality and integrity.

When is Fluorescent / Liquid Penetration Testing required

Quality control purposes often incorporate FPI in manufacturing and maintenance operations to ensure components are free from surface cracks, porosity, laps, and other discontinuities compromising safety and reliability. Regulatory compliance, as stipulated by entities like the Federal Aviation Administration (FAA), the Nuclear Regulatory Commission (NRC), and the Department of Defense (DoD), may necessitate FPI on critical components to ensure safety and reliability. For failure analysis, FPI aids in investigating component failures by identifying the location and extent of surface discontinuities contributing to the failure. Routine maintenance procedures can benefit from FPI, where regular inspections help identify and address surface discontinuities before they pose safety or reliability concerns.

Dye Penetrant Inspection vs Fluorescent

Dye Penetrant Inspection (DPI) involves a colored dye penetrating surface discontinuities through capillary action. After wiping off excess dye, a developer is applied to draw out the dye from discontinuities, making them visible without the need for a UV light source.

Fluorescent Penetrant Inspection (FPI) utilizes a fluorescent dye applied to the part's surface, penetrating discontinuities through capillary action. After removing excess dye and applying a developer, FPI showcases discontinuities as bright indications under UV light. FPI detects smaller and shallower surface discontinuities compared to DPI and provides greater contrast between indications and the background surface.

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