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A practical guide for purchasers and supply engineers.

In industry, Non-Destructive Testing (END) is fundamental to ensuring the quality, safety, and conformity of parts and equipment. However, many Requests for Quotations (RFQs) fail because they do not correctly specify what is being requested—whether it is the  contracting of END services  or the  acquisition of supplies and equipment  to perform it.

Below, we present a practical guide to preparing clear and complete RFQs, with real-world examples from Metal-Chek and Supermagna products.

1. Define what you are buying: a service or a supply.

First of all, determine if your RFQ will be for:

• END service  – the supplier performs the test and delivers the technical report.
• Materials/supplies/equipment for END  – your team or service provider will use the purchased products to perform the test.

This distinction avoids confusion and ensures that the specifications are suitable for what you want to buy.

2. Specifying the contracting of the END service

When hiring a service, describe how the test should be conducted and what acceptance criteria will be adopted.

a) Method and technique

Specify the method and technique:

• Example: Liquid penetrant testing, Type I, Method A, Level 2, using  Metal-Chek FP 91
• Example: Dry magnetic particle extraction, white powder, using  Supermagna WD 55

b) Reference standard

Define the applicable standard (ASTM E165, ASTM E709, ASME Section V, AWS D1.1 or internal standards such as Petrobras N-1596/N-1598).

c) Acceptance criteria

Determine codes and levels (e.g., ASME VIII Div.1, EN 1369, Level 2 or 3).

d) Inspector qualifications

Require SNQC/ABENDI or ASNT SNT-TC-1A certification, Level II or III, depending on the method.

e) Implementation conditions

Include requirements such as cleanliness, adequate lighting (lux or µW/cm²), temperature, humidity, and application times.

f) Documentation and traceability

Request reports with photos, sketches, and part identification, ensuring traceability by batch or serial number.

3. Specifying the purchase of materials and equipment for END

When purchasing supplies or equipment, the RFQ (Request for Quotation) should contain technical details of the product.

a) Penetrant Liquids

• Fluorescent: Metal-Chek FP 91 , Type I, Method A, Level 2
• Visible: Metal-Chek VP 30 , Type II, Method A
• Visible: Metal-Chek VP 31 , Type II, Method C

b) Developers

• Dry:  Metal-Chek D72 , form a
• Non-aqueous:  Metal-Chek D70 , form d, e
• Aqueous:  Metal-Chek D76 , form b

c) Removers / Cleaners

• Solvent: Metal-Chek E 59 , Class 2
• Solvent: Metal-Chek R 501 , Class 1

d) Magnetic Particles

• White dry track: Supermagna WD 55
• Yellow dry track: Supermagna YD 404
• Fluorescent wet process: Supermagna LY 2000
• Visible red wet path: Supermagna RW 222
• Visible black wet sample: Supermagna BW 333

e) Equipment

• Yokes:  Supermagna Yoke HMM6

4. Best practices for any END RFQ

• Be specific: avoid generic terms like “LP test” without specifying the method, type, and standard.
• Standardize the descriptions across all requests.
• Approve the technical proposal before the price.
• Include safety and environmental requirements (PPE, proper disposal of products).

Conclusion

A clear specification — whether for contracting END services or acquiring Metal-Chek and Supermagna supplies — ensures that the process is executed with quality, reduces risks, and avoids rework.

Want to learn more?  Read also: How to choose the ideal penetrant type for each application.

Speak to our technical team.

Follow us on Instagram: @metalchek

In penetrant testing, choosing the correct product is crucial for the  sensitivity, reliability, and compatibility of the test. Specifying an inappropriate penetrant can lead to incomplete detection of discontinuities, material damage, or even unnecessary rejections.

This guide will help you understand which factors to consider  and how to select the most suitable penetrant for your application, with real-world examples from the Metal-Chek line.

1. Begin by understanding the classification of penetrants.

Penetrant liquids are classified primarily by  type, removal method, and sensitivity level.

a) Type

• Type I – Fluorescent.
  High sensitivity, inspection under UV light. Ideal for detecting very fine discontinuities.
  Ex.:  Metal-Chek FP 91 , Type I, Method A, Level 2.
• Type II – Visible.
  Indications visible to the naked eye under white light. Simpler and faster, ideal for field inspections.
  Ex.:  Metal-Chek VP 30 , Type II, Method A;  Metal-Chek VP 31 , Type II, Method C.

b) Removal method

• A – Washable with water  (easy removal with water)
• B – Lipophilic post-emulsifiable  (emulsifier applied after the penetrant)
• C – Solvent removable  (removal with cloth and solvent, such as  Metal-Chek E 59  or  Metal-Chek R 501 )
• D – Hydrophilic post-emulsifiable  (water-based emulsifier)

c) Sensitivity level (Type I)

It ranges from Level 1 (low sensitivity) to Level 4 (ultra-high). The more critical the component, the higher the recommended level.

2. Consider the material to be inspected.

• Stainless steels, titanium, and special alloys : require penetrants with low halogen and sulfur content, and compatible developers.
  Ex.:  Metal-Chek FP 91  with contaminant certification according to ASTM E165.
• Carbon steel and ferrous materials : greater flexibility of choice, depending on the acceptance criteria.
• Porous materials : require care to avoid excessive penetration and false readings.

3. Inspection environment and conditions

• Environments with low, controlled lighting : fluorescent (Type I) is preferable.
• Field inspection or areas with restricted UV lighting : opt for visible (Type II).
• Locations without running water : consider method C (removable solvent) for cleaning up excess water.

4. Compliance with standards and criteria

Always align the penetrant and developer with the required standard:

• ASTM E165, ISO 3452, ASME Section V, Petrobras N-1596.
  And include in the RFQ the requirement for a batch certificate and SDS (Safety Data Sheet).

5. Combining penetrant, developer, and remover

For an effective test, choose a compatible set:

• Metal-Chek FP 91  (fluorescent) +  Metal-Chek D70  (non-aqueous developer) +  Metal-Chek E 59  (solvent remover).
• Metal-Chek VP 30  (visible) +  Metal-Chek D72  (dry developer) +  Metal-Chek R 501  (solvent remover).

Conclusion

Choosing the right penetrant is not just a matter of preference — it’s a guarantee of reliable results and compliance with technical standards.
Metal-Chek offers solutions for different sensitivity levels, methods, and types, always accompanied by technical certification and specialized support.

Contact the Metal-Chek technical team.

Follow us on Instagram: @metalchek

Read also:

The Main Methods of Industrial Inspection and How to Choose the Ideal One

How to Choose the Ideal Penetrant Testing Process for Your Application?

Do you know what makes a penetrating liquid effective?

Industrial leaks are not just an operational headache. They can compromise a plant’s safety, productivity, and environmental compliance. Therefore, early leak detection is an essential practice for any modern industry, especially in contexts like Industry 4.0, where continuous monitoring and predictive maintenance are key to efficiency.

In this article, we will explore one of the main methods for detecting industrial leaks, focusing on non-destructive techniques based on the use of fluorescent additives and UV flashlights. The goal is to provide a comprehensive, technical, and accessible overview for professionals working in industrial maintenance, inspection, and sectors where operational reliability is non-negotiable.

Why is accurate leak detection vital?

Before we delve into the method, it’s worth reiterating: leaks can cause significant damage. We’re talking about:

• Loss of industrial fluids (oil, gas, water, compressed air, refrigerant, among others);
• Increased operating costs;
• Risks of fire or contamination;
• Damage to equipment and structures;
• Production interruptions;
• Legal and environmental non-conformities.

In a scenario where predictive maintenance is increasingly integrated into industrial strategies, the use of non-destructive testing (END) to identify and correct leaks has become a competitive differentiator.

The technology of fluorescent additives

Detection with fluorescent dyes is one of the safest, simplest, and most effective techniques for identifying leaks. The fluorescent additive works effectively in any closed circulatory system where liquids are used for lubrication, hydraulics, cooling control, and fuel systems.

The method involves adding a fluorescent additive — usually a colored liquid miscible with the system fluid (such as oil, water, fuel, or coolant) — which concentrates at the leak points. When exposed to ultraviolet (UV) light, this additive emits intense fluorescence, making even the smallest leaks visible.

How the method works:

1. Fluorescent dye is added to the system to be inspected (pipes, tanks, heat exchangers, radiators, hydraulic systems, etc.).
2. After a period of operation, the system is inspected with a UV flashlight .
3. Leaks are visually identified as bright spots, usually in shades of green or yellow.

Advantages:

• Non-destructive method;
• Affordable cost;
• Quick and visual detection;
• Excellent for small leaks;
• Compatible with various types of fluids.

Typical applications:

• Industrial and automotive refrigeration systems;
• Oil pipelines;
• Plumbing installations;
• Reservoirs;
• Air conditioning equipment (HVAC/R).
• Fuel lines;

The role of UV flashlights

UV flashlights are indispensable tools in this process. Their main function is to emit ultraviolet radiation, in the 365nm range, to excite the fluorescent molecules of the additive, making the leak visible to the naked eye.

Characteristics of UV flashlights:

• Laptops;
• Battery powered;
• IP certification;
• Specific power and wavelength for greater visual contrast;
• Long range;

Good practices in leak inspection

• Use certified additives that are compatible with the system fluid;
• Follow the manufacturer’s instructions regarding concentration and circulation time;
• Use UV flashlights with the appropriate wavelength;
• Document the identified leak points with photos and technical reports.

Safety and environment

The choice of method should always consider environmental and health impacts. High-quality fluorescent additives have NSF and OEM Grade certification, but their disposal must comply with local environmental regulations. The use of UV flashlights must also follow safety standards, avoiding prolonged direct exposure to radiation.

Conclusion: technology combined with intelligent maintenance

Leak detection using fluorescent additives and UV flashlights represents an efficient, affordable, and visually powerful solution for maintaining the integrity of industrial systems.

If your company operates in the industrial and commercial sectors, industrial maintenance, inspection, and welding, incorporating these practices can represent significant cost savings, in addition to ensuring compliance, safety, and performance.

Want to know which fluorescent additives and UV luminaires are ideal for your type of application? Talk to the Metal -Chek technical team — a national specialist in solutions for Non-Destructive Testing .

Contact us: (11) 3515-5287

Follow us on Instagram: @metalchek

Every effective inspection begins with observation — not just what the eyes see, but what a technical and experienced eye is able to interpret. Visual Inspection (VI) is the initial step in identifying discontinuities , defects, wear, and anomalies that can compromise the integrity and performance of equipment.

More than just a superficial check, VT acts as an initial filter in quality control, directly contributing to cost reduction, risk prevention, and increased operational efficiency.

Furthermore, visual inspection serves as the gateway to more advanced non-destructive testing techniques, such as penetrant testing, magnetic particle testing, and ultrasound. In other words, when a visual indicator is detected, it’s the right time to deepen the analysis with complementary and more sensitive methods.

Although it seems simple, visual inspection requires much more than just “looking”:

• Technical training
• Knowledge of acceptance criteria
• Adequate lighting
• Support tools and instrumentation
• Evidence documentation

Visual Inspection in the Industry 4.0 Era

Those who think that Visual Inspection (VI) has lost importance with the advancement of automation are mistaken. On the contrary — it has evolved and integrated with new technological resources, expanding its reach, precision, and speed.

Today, VT is an active part of Industry 4.0 and can be combined with state-of-the-art digital solutions:

• Artificial intelligence for image recognition.
• Drones for inspections at heights or in hazardous areas.
• 4K cameras with thermal sensors
• Predictive analytics connected to digital dashboards

Most common applications of visual inspection.

Visual Inspection (VI) is widely used in various industrial sectors as a quick and effective assessment tool. Its main objective is to identify visible irregularities that may compromise the structural integrity, functionality, or safety of components and equipment.

The following table summarizes the main applications and what is sought to be identified in each case:

Equipment and Resources Used in Visual Inspection

Although many visual inspections are done with the naked eye, the use of auxiliary equipment significantly enhances the accuracy and reliability of the test. Some resources used include:

 Adequate natural or artificial light: Ensures adequate visibility. Poor lighting can compromise the detection of discontinuities.

Magnifying glasses and magnifying lenses: They amplify small details, allowing the identification of surface cracks, porosity, inclusions, or lack of fusion in welds.

Borescopes and industrial endoscopes: Optical instruments used for inspecting hard-to-reach areas, such as pipes, internal welds of pressure vessels, and aeronautical components.

Rulers, gauges and jigs: Tools for measuring dimensions, weld angles, weld bead profiles and alignments.

High-resolution cameras: They facilitate photographic documentation and historical comparison during periodic inspections.

Digital inspection and recording software: With the advancement of Industry 4.0, integrating visual inspections with digital systems allows for recording occurrences, generating reports, and maintaining traceability in accordance with regulatory requirements.

Tip:
In low-light environments, the use of adequate artificial light is not optional — it’s mandatory.

Best practices in performing visual inspections.

To ensure the effectiveness of visual inspection and the reliability of results, it is essential to adopt well-defined operational practices. Standardizing execution through written procedures and operational checklists helps minimize human error and ensure consistency in assessments. A simplified model is presented below that can be adapted to the needs of each sector:

BEFORE INSPECTION:

• Check that the surface is clean (free of contaminants such as paint, oil, grease, rust, dust, or debris).
• Check the ambient lighting (it should be sufficiently intense and evenly distributed, allowing for an accurate assessment of the surface. It is important to avoid reflections, shadows, or glare, especially on polished materials or those with irregular geometry. In locations with little natural light, the use of adjustable and directional artificial light sources is recommended to ensure good visibility).
• Assess the inspector’s physical and visual condition (e.g., fatigue, use of glasses).
• Assess the need for additional equipment and resources.

DURING THE INSPECTION:

• Observe surface continuity: deformations, cracks, oxidation.
• Check weld beads: profile, spatter, lack of fusion.
• Use magnifying glasses on areas with suspicion or small details.
• Photographing and documenting irregularities
• Assess the need for additional tests (liquid penetrant, magnetic particles, etc.).

AFTER INSPECTION:

• Record keeping and traceability (maintaining a history of inspections, photos, reports, inspection maps, and checklists with acceptance criteria. These records ensure traceability, effective audits, and support decision-making).
• Storing records digitally ensures traceability and facilitates audits.

Integration of Visual Inspection with Other END Methods

Visual Inspection (VI) is the starting point for most Non-Destructive Testing (END). While it can identify various surface flaws, it does not always provide sufficient information for a complete assessment of the component’s integrity. Therefore, it is essential to integrate it with complementary methods, especially when there are visual suspicions that require technical confirmation.

The table below shows how VT connects to the main END methods and the benefits of this combination:

Normative References

Visual inspection is governed by several technical standards that ensure standardized procedures, reliable results, and compliance with legal and industrial requirements. Below, we highlight some applicable technical standards:

• ISO 17637 – Visual Inspection of Welds in Metallic Materials: establishes requirements for performing visual inspection of welds, including acceptance criteria and recommended techniques.
• NBR 14842 – Visual Inspection of Welds: national procedures and requirements that guide the practice of visual inspection of welds.
• ASME Section V, Article 9 – Requirements for Visual Inspection: a standard widely used in the pressure equipment and boiler making industry.
• Petrobras Technical Standards (Examples: N-1596, N-1598, N-2370) – Specific guidelines for visual inspections in the oil and gas sector.

The First Line of Defense for Quality

Visual inspection is much more than just a keen eye—it’s an essential technical barrier against failures that compromise safety, productivity, and regulatory compliance.

Implementing a well-structured visual inspection program is the first step towards operational excellence. Furthermore, when combined with Metal-Chek methods such as Liquid Penetrant, Magnetic Particle, and Leak Detection, visual inspection transforms into an ecosystem of industrial reliability.

Next Steps for Your Company

To strengthen your visual inspection program and increase the reliability of your processes, consider:

✅ Assess the maturity of your visual inspection program.

✅ Empower your team with training based on recognized standards.

✅ Standardize checklists and procedures with specialized technical support.

✅ Invest in quality accessories and equipment to complement the visual stage.

If your company wants to increase process reliability and ensure technical compliance, Metal-Chek is your ideal partner.

Speak with our technical team and discover how we can help transform your inspection routines into competitive advantages. 

Follow us on Instagram: @metalchek

Contact us at: (11) 3515-5287

If you want to guarantee accuracy, compliance, and operational safety in your Non-Destructive Testing (END), equipment calibration is not an optional step—it’s indispensable.
Companies that neglect this practice face serious risks:
❌ Inaccurate reports
❌ Undetected failures
❌ Non-conformities in audits
❌ Operational and reputational damage

➡️ When equipment is out of calibration, reliability disappears — along with operational safety.

What is Calibration and why is it Vital in END?

Calibration is a process of comparing two instruments (the measurand and the measured). This comparison involves calculating error and uncertainty, and these results are presented in a document called a calibration certificate.

• ✅ Relationship between measurement values ​​and uncertainties; 
• ✅ Technical standards are being met;

Standards such as ASME Section V, ASTM E1417, ASTM E1444, ASTM E3024, and ASTM E709 require that your equipment be calibrated for the results to have technical and legal validity.

Why is calibration a key differentiator?

1. Ensures Technical Precision

• False positives → good parts are discarded unnecessarily.
• False negatives → errors go unnoticed.

Both put security at risk, increase costs, and compromise the company’s reputation.

2. Avoid Penalties in Audits

Industries such as oil and gas, aeronautics, rail, and automotive are inflexible regarding non-compliant equipment.
Golden tip: Always demand certificates traceable to the RBC (Brazilian Calibration Network) or recognized international standards.

3. Reduces costs associated with rework.

Investing in calibration is cheaper than correcting errors caused by miscalibrated equipment.

Which equipment needs to be calibrated?

Penetrant Testing (PT)

• Radiometers/Photometers
• Thermometers
• Water pressure gauges
• Compressed air pressure gauges

Magnetic Particle (MP)

• Gaussmeters (Residual)
• Magnetic Field Meters
• Ammeters
• Timers
• Magnetizing equipment (Stationary Machines)
• Settling tubes

When should the equipment be calibrated?

The ideal calibration frequency is determined according to applicable standards.

How to Guarantee Traceability?

Compliance isn’t something you improvise. Follow these practices:

• ✔ Hire laboratories accredited by Inmetro (ABNT NBR ISO/IEC 17025);
• ✔ Archive and update calibration certificates;
• ✔ Use digital checklists with automatic due date alerts;

[PRACTICAL CHECKLIST] How to Organize Your Calibration Routine

Calibration means Safety, Reliability, and Quality.

In the world of Non-Destructive Testing, calibration is an act of technical responsibility and a commitment to safety.

Metal-Chek offers the best consumables and accessories to ensure your penetrant testing, magnetic particle testing, and leak detection are accurate, traceable, and reliable.

You may have the best partner laboratory — but if your products are not of high quality, the results will be compromised.

Ready to increase the reliability of your tests?

→ Contact our technical team right now.
We’ll help you select the best Metal-Chek products to make your tests safer and more effective.

Follow us on Instagram: @metalchek

Contact us at: (11) 3515-5287

The role of inspections in modern industrial maintenance.

Industrial maintenance has evolved by leaps and bounds in recent decades. With the advancements of Industry 4.0 , new technologies, sensors, and continuous monitoring systems have been integrated into the daily operations of factories and industrial plants. However, no matter how innovative these emerging technologies are, one foundation remains unshaken: inspection through Non-Destructive Testing (END) .

Inspecting without causing damage to parts and structures is a technical, economic, and strategic advantage. In sectors where safety and reliability are critica l— such as oil and gas, aeronautics, automotive, civil construction, metallurgy, and industry and commerce in general — END (Non-Destructive Testing) is indispensable for predicting failures, ensuring the integrity of components, and increasing the lifespan of assets.

In this article, we will present a practical guide to structuring an effective non-destructive testing program. We will cover what should be taken into account, which professionals should be involved, when to apply the techniques, and how to document and interpret the results. By the end, you will have an essential checklist that can be adapted to different industry realities.

Why plan a Non-Destructive Testing program?

Imagine a ship undertaking long sea voyages. Instead of waiting for something to break at sea, a routine of inspections allows for the identification of cracks, corrosion, and structural flaws before they become catastrophic. This applies to an urban bridge, mining equipment, or a pressure vessel in a chemical plant.

A well-structured END (Non-Destructive Testing) program is the cornerstone of efficient industrial maintenance , integrated with the philosophy of predictive maintenance , operational reliability, and occupational safety. Furthermore, it reduces costs associated with unplanned downtime and serious failures.

Essential Checklist: How to Structure an END Program

1. Identify the critical assets.

The first step to an efficient plan is knowing what will be inspected. Make a list of the plant’s most critical assets: equipment operating under high pressure, structures subject to repetitive stress, components exposed to corrosion, or welds in strategic locations.

Practical tip: use tools such as FMEA (Failure Mode and Effects Analysis) or RCM (Reliability-Centered Maintenance) to identify assets that deserve more attention.

2. Define clear objectives.

Each inspection should have a purpose: to detect cracks? To assess the quality of a weld? To check for leaks using penetrant testing? Define the objectives to determine the best technique and frequency of evaluation.

3. Choose the appropriate Non-Destructive Testing methods.

ENDs encompass a range of methods. Among the most common are:

• ◽ Penetrant Testing (PT): ideal for detecting surface cracks in non-porous metals. Widely used in weld inspection.
• ◽ Magnetic Particles (MP): efficient for detecting surface and subsurface discontinuities in ferromagnetic materials.
• ◽ Ultrasound (UT): allows for the verification of internal defects, material thickness, and density variations.
• ◽ Industrial Radiography (X-ray): ideal for detecting volumetric flaws in welded joints or cast parts.
• ◽ Visual Inspection (VI): the first line of defense, it must be carried out systematically, with appropriate equipment and lighting.

The choice depends on the type of material, the defect to be detected, the applicable technical standards, and operational feasibility.

4. Determine the frequency of inspections.

Each piece of equipment has an estimated lifespan, but actual operating conditions can accelerate wear and tear and failures. Therefore, the frequency of inspections should consider:

• ◽History of failures
• ◽Operating environment (abrasive, corrosive, humid)
• ◽Mechanical loads and stresses
• ◽Specific regulatory standards (e.g., NR-13 for pressure vessels)

Practical example: in sectors involving constant inspection and welding, such as boiler making and oil pipelines, the frequency should be more rigorous.

5. Develop standardized operating procedures (SOPs).

Having standardized operating procedures (SOPs) is essential to ensure repeatability, traceability, and quality. These procedures should include:

• ◽Techniques to be applied
• ◽Surface preparation steps
• ◽Equipment and consumables used
• ◽Acceptance and rejection criteria
• ◽Photographic records and reports

At Metal-Chek, for example, penetrant, developer, and remover fluids comply with AMS 2644 and Petrobras N-2370 standards, ensuring standardization in critical inspections.

6. Train the technical team.

The professionals responsible for applying END (Non-Destructive Testing) must be qualified, according to the requirements of the ABNT NBR ISO 9712 standard or equivalent international standards. They are classified into three levels:

• ◽Level 1: Performs inspections following detailed instructions.
• ◽Level 2: Interprets results, prepares reports, and instructs Level 1.
• ◽Level 3: Designs and validates procedures, leads audits, and ensures regulatory compliance.

An industry that invests in training and certifying its team reaps the rewards in reliability, safety, and performance.

7. Document and manage the results.

Photographic records, reports, and historical data should be stored in an organized manner. This facilitates trend analysis, audits, and the planning of corrective actions. With the digitization of processes and the arrival of Industry 4.0, integrated management platforms with IoT, sensors, and cloud databases make this process more agile and secure.

Integration with Industry 4.0: END as a link between technology and reliability.

A well-planned inspection program goes beyond conventional maintenance. It integrates with the emerging technologies of Industry 4.0.

• ◽ Onboard sensors detect vibration, temperature, or microcracks in real time.
• ◽ Predictive systems warn when a component is close to failure.
• ◽ Robotic inspections in hard-to-reach locations increase safety.
• ◽ Predictive analytics software cross-references historical data with recent inspections to predict future failures.

In other words, non-destructive testing ceases to be a one-off action and becomes a strategic part of the company’s operational intelligence.

Inspections and Welding: A Critical Relationship

A large proportion of structural failures originate from poorly executed or degraded welds over time. The correct application of END (Non-Destructive Testing) in this context is vital for:

• ◽ Ensure weld quality during manufacturing.
• ◽ Detect thermal or fatigue cracks
• ◽ Control stress corrosion cracking (especially in harsh industrial environments)

Techniques such as liquid penetrant and magnetic particles are particularly effective in this scenario, with the advantage of low cost and high sensitivity.

Fictional case: Inspection Program at a Metallurgical Plant

Let’s imagine a plant that performs casting and machining of large metal parts. The technical management decided to implement a robust inspection program after recurring failures in transmission shafts.

Steps followed:

1. Mapping of critical assets: shafts, gearboxes and welds on structural supports.
2. Choice of END methods: liquid penetrant for welds, ultrasound for shafts.
3. Drafting SOPs: based on ASTM and Petrobras standards.
4. Staff training: Level 2 certification for inspectors.
5. Defined frequency: quarterly inspections and extraordinary inspections after major maintenance.
6. Digitizing results: cloud-based reports accessible to engineering.

Results: In less than a year, the failure rate dropped by 80%, and operational reliability increased. An example of how planning and technique make a difference in industrial maintenance.

An END plan is a safety and productivity plan.

Planning a non-destructive testing program is not just a technical requirement, but a strategic decision. In times when industry needs to be increasingly efficient, safe, and sustainable, adopting preventive and reliable practices is the right path.

Metal-Chek , as a national leader in providing products and solutions for END (Non-Destructive Testing), is ready to support companies that want to raise the standard of their inspections. Our penetrant liquids , magnetic particles, UV equipment, developers, and removers meet the highest national and international standards.

Whether it’s welding, industrial assembly, or structural integrity analysis, count on Metal-Chek to ensure your inspection program is one step ahead. Because reliability isn’t improvised—it’s built with planning, technique, and excellence.

Final Checklist: Efficient END Program

✅ Map critical assets
✅ Define clear objectives for each inspection
✅ Choose appropriate END methods
✅ Establish periodicity according to standards and criticality
✅ Develop SOPs according to best practices
✅ Train and certify the technical team
✅ Manage and digitize the results

If you want to take the next step and structure your inspection program with the best supplies and equipment, contact the Metal-Chek technical team.

Follow us on Instagram: @metalchek

Contact us at: (11) 3515-5287

Operational reliability is one of the cornerstones of modern industry. With increasing pressure to reduce costs and enhance asset safety and efficiency, predictive maintenance has become essential. In this context, non-destructive testing (END) plays a decisive role, adding precision and safety to technical and operational decision-making.

The adoption of continuous monitoring technologies and smart sensors has driven the digital revolution in industry, aligning with the principles of Industry 4.0 . Within this ecosystem, ENDs (Non-Destructive Testing) are fundamental for validating data and expanding the ability to anticipate failures.

This article explores how the integration of sensors, monitoring systems, and methods such as liquid penetrant testing , magnetic particle testing, and leak detection contributes to the efficiency of predictive maintenance. We also present how Metal-Chek, a national leader in END products, enhances this integration with technology, quality, and regulatory compliance.

Predictive Maintenance: Far Beyond Traditional Inspection

Predictive maintenance relies on collecting and analyzing data in real time to predict failures and avoid unexpected downtime. It is a strategy focused on the actual condition of the equipment, in contrast to corrective (post-failure) or preventive (fixed interval) maintenance.

Common tools of predictive maintenance:

• Temperature, vibration, and pressure sensors;
• Spectral and eddy current analysis;
• Infrared thermography;
• Ultrasound and tribological analysis (oil monitoring);
• And of course, Non-Destructive Testing , which complements automated alerts with a detailed and visual approach to the failure.

Technical and economic benefits:

• Prevention of unscheduled downtime;
• Increased lifespan of components and assets;
• Cost reduction through reduced rework and parts replacement;
• Improved safety in industrial operations and the trade of high value-added products;

Companies in the industrial and commercial sectors have been increasingly investing in technologies that allow for greater operational predictability, aligning themselves with the global trend of digital transformation in industry.

Non-Destructive Testing: The Basis of High-Precision Inspection

Non-destructive testing (END) techniques are inspection methods that analyze materials, parts, and welds without compromising their structural integrity. They are widely used to detect cracks, inclusions, porosity, delamination, and other defects that cannot be visually identified.

In predictive maintenance, END (Non-Destructive Testing) offers:

• Visual and technical confirmation of anomalies detected by sensors;
• Monitoring the spread of structural defects;
• Photographic record and traceable technical documentation;
• Support for decision-making based on concrete evidence;
• Reducing uncertainty during planned interventions;
• Compliance with national and international standards for quality, safety, and traceability.

Main methods:

• Penetrant Liquid (PL) : excellent for surface cracks in metals and non-metallic materials;
• Magnetic Particles (MP) : used on ferromagnetic materials, detects surface and subsurface cracks;
• Industrial Ultrasound : ideal for locating internal defects with high precision;
• Industrial radiography : provides internal images of complex structures;
• Eddy Current : useful for thin layers and quick inspections;
• Infrared thermography : thermal visualization of abnormal heating points.

These methods are routinely applied in inspections of welding, boilers, pressurized pipelines, valves, aeronautical structures, and parts subject to mechanical wear. The advantage lies in the early detection of cracks, porosity, delamination, and other types of structural defects, even in aggressive or difficult-to-access environments.

Industry 4.0 and the Intelligent Integration between Sensors and END

Industry 4.0 is transforming the way we manufacture, maintain, and manage industrial assets. The connectivity between sensors, software, machines, and people enables a systemic and predictive view of the entire operation.

In this context, ENDs (Non-Destructive Testing) take on a new function: to physically validate the data collected automatically . In other words, the sensors detect abnormal operating patterns, while the tests confirm (or rule out) the presence of real structural flaws.

Practical example:

A sensor detects increased vibration in a critical motor. Subsequently, a penetrant testing is performed on the support base area, revealing a superficial “U”-shaped crack. This visual confirmation allows for localized interventions, reducing downtime.

Benefits of integration:

• Correlation between digital data and physical evidence;
• Decisions based on technical grounds;
• Optimization of maintenance plans;
• Unnecessary replacements are avoided;
• Minimizing downtime;
• Increasing predictability and reducing uncertainty.

The integration between ENDs (Non-Destructive Testing) and sensors is an essential step towards achieving autonomous maintenance and reliability-based management . This approach fits perfectly into the digitalization strategies of Brazilian industry and commerce.

Metal-Chek Solutions: High Performance for Predictive Inspections

Metal-Chek offers a complete line of products for Non-Destructive Testing (END) , developed with high-quality raw materials and rigorous manufacturing control.
The Penetrant Liquids , Removers, and Developers meet the requirements of AMS 2644 and Petrobras N-2370 standards, and also comply with Petrobras N-1596, ASME Section V, ASTM E1417, and ISO 3452-3 standards.

In the Magnetic Particle line, SuperMagna offers consumables with balanced particle size, ensuring maximum sensitivity and precision in detecting discontinuities. The particles are manufactured according to AMS 3040 to 3046 standards and meet the requirements of Petrobras N-1598, ASTM E1444, ASME Section V, and ASTM E709 standards.

This credibility positions the brand as a strategic partner for companies that adopt predictive maintenance with a focus on efficiency and safety.

These products are present in segments such as oil and gas, aerospace, rail, mining, power generation, and industrial manufacturing, consolidating the application of END as an integral part of predictive strategy.

Featured solutions:

Penetrant Liquid

Metal-Chek’s penetrant liquid is ideal for detecting surface discontinuities in metallic and non-metallic materials (such as aluminum, stainless steel, nickel alloys, ceramics, and technical plastics). The product line ranges from visible to fluorescent products, offering high penetration and contrast power.

Process steps:

1. Surface cleaning;
2. Application of the penetrant (visible or fluorescent);
3. Controlled penetration time;
4. Excess removal;
5. Applying the developer;
6. Assessment by a qualified inspector.

Highlights of the Metal-Chek Line:

• VP 30: Visible, water-washable – ideal for rough surfaces.
• VP 31: solvent-removable visible – suitable for critical inspections of metals subject to oxidation.
• FP 91: Water-washable fluorescent – ​​general use with medium sensitivity.
• High Temperature VP 302: inspections of parts operating between 52 °C and 120 °C.

Magnetic Particles

An effective method for detecting surface and subsurface cracks and discontinuities in ferromagnetic materials. The SuperMagna line offers extreme precision and sensitivity. Available in dry and wet versions, fluorescent or visible.

Application:

• Cast, rolled, machined or welded parts ;
• Inspections during or after manufacturing;
• Surfaces exposed to high temperatures (up to 300 °C in some products).

How it works:

• Magnetizing the workpiece with a yoke or stationary equipment;
• Particle application (dry or wet methods);
• Visual identification of the defect by the agglomeration of particles in the magnetic leakage field.

Highlights of the SuperMagna Line:

• SuperMagna LY 3000: latest generation, wet fluorescent, extremely high sensitivity.
• SuperMagna WD 55 / YD 404: dry process, for hot parts (up to 300°C)
• SuperMagna LY 2000: the best-known wet fluorescent printer on the national market.
• SuperMagna CRL 265: dual particle, ideal for environments with alternating visible and UV-A inspection.

Equipment:

YOKE HMM6: high-performance, robust, and certified portable equipment for use in demanding industrial environments.

These products are present in segments such as oil and gas, aerospace, rail, mining, power generation, and industrial manufacturing, consolidating the application of END as an integral part of predictive strategy.

Real-World Applications of Predictive Maintenance with END

1. Aeronautical Industry

• High operational risk requires strict control.
• Lightweight alloy parts, such as titanium and aluminum, are routinely inspected with fluorescent penetrant liquid .
• The part’s history is digitally recorded for complete traceability.

2. Iron and Steel Industry and Metallurgy

• High temperatures and mechanical stress accelerate degradation.
• Magnetic particle inspection reveals cracks in cylinders, rollers, and shafts while they are still in the production line.
• Maintenance can be planned without interrupting the production process.

3. Power Generation (Hydroelectric, Thermal, Wind Power Plants)

• Turbines, ducts, and blades require periodic inspection.
• Sensors detect abnormal vibrations or noises.
• ENDs confirm the failure before there is a risk of collapse.

4. Railways

• Rails and axles are subject to cyclic stress.
• Predictive maintenance allows for scheduling replacements before breakdowns occur.
• Metal -Chek provides portable kits for quick and effective field inspections.

5. Shipbuilding and Offshore Industry

• Harsh environments with salinity, humidity, and temperature variations.
• END (Non-Destructive Testing) is applied to structural welds, valves, hulls, and cable passages.
• The use of particles and liquids specifically designed for marine environments ensures precision even under adverse conditions.

The Strategic Importance of ENDs in Industry and Commerce

Companies in the industrial and commercial sectors that integrate END (Non-Destructive Testing) into their predictive maintenance process reap significant results: reduced downtime, greater quality control, legal security, and market competitiveness.

In addition to technical benefits, non-destructive testing contributes to:

• Meeting regulatory requirements (INMETRO, ANP, ANAC, among others);
• Aligning with ESG and sustainability standards;
• Avoid fines and losses due to undetected errors;
• To strengthen the brand image as synonymous with quality and innovation.

Metal-Chek, with over 40 years in the market, directly participates in this evolution, offering technical support, training, and complete solutions adapted to each industrial segment.

The integration of predictive maintenance and non-destructive testing is an irreversible trend. In the era of Industry 4.0, the ability to predict, detect, and correct failures before they cause damage is the differentiating factor that separates efficient companies from vulnerable ones.

Methods such as liquid penetrant testing and magnetic particle testing are indispensable allies in technical inspection, enabling safe, economical, and sustainable production. With Metal-Chek products, this process becomes even more reliable and effective.

Regardless of your industry — energy, transportation, metallurgy, or aerospace — investing in ENDs is investing in excellence.

The integration of predictive maintenance and non-destructive testing represents the most effective path to operational excellence in the Industry 4.0 era. The ability to accurately anticipate failures, make data-driven decisions, and ensure the structural safety of assets is the new competitive differentiator.

Metal-Chek directly contributes to this evolution by providing reliable, standardized products adapted to the realities of the industrial sector. Whether in welding , inspection of critical parts, or continuous monitoring of structures, the presence of END (Non-Destructive Testing) enhances the intelligence of predictive maintenance.

Invest in technology, invest in security, invest in predictability. Count on Metal-Chek.

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In highly regulated sectors such as aeronautics, nuclear, rail, oil and gas , operational safety depends on excellence in the inspection of highly critical components . In these contexts, Non-Destructive Testing (END) is indispensable for preventing structural and functional failures that could compromise the integrity of the system.

However, the effectiveness of END goes beyond the detection of discontinuities: it depends directly on the traceability of the process and the reliability of the results obtained . Metal-Chek, with decades of expertise in END solutions, reinforces the importance of the rigorous application of national and international technical standards , ensuring the quality and repeatability of the tests.

Traceability: The Documentary Basis of Reliability

Traceability in END (Non-Destructive Testing) begins with the precise identification of the inspected component, which must have a unique registration number. This identifier must be linked to a robust set of information, including:

• Date and location of the rehearsal;
• Name and certification of the inspector (according to ISO 9712);
• Technical procedure applied;
• Equipment used (with traceable calibration);
• Environmental conditions;
• Results and images documented.

This data is incorporated into the technical report and acceptance form, allowing for a complete history of the part, a mandatory practice in accordance with the requirements of ISO 9001, ASME BPVC, API, and NADCAP.

Reliability: Guaranteed Technical Reproducibility

The reliability of Non-Destructive Testing is related to the reproducibility and repeatability of the results. If a component is inspected again under the same conditions, the data must be consistent, within acceptable technical margins.

This is only possible when:

• The procedures follow validated operational instructions ;
• The inspectors are qualified and receive ongoing training ;
• The inspection environment is controlled ;
• There is cross-checking by independent inspectors;
• Technologies for automatic data recording and integrated digital documentation are used .

And why trust Metal-Chek?

Metal-Chek is a national leader in products and solutions for Non-Destructive Testing, with in-depth knowledge of current END standards and active participation in the sector’s technical evolution. Our commitment to reliability, traceability, and regulatory compliance strengthens the confidence of clients operating in critical and highly demanding markets.

Ensuring traceability and reliability in Non-Destructive Testing is not just a regulatory requirement—it’s a practice that protects lives, assets, and reputations. By applying END in a standardized way, with complete documentation and technical rigor, your company ensures operational safety and international quality recognition.

The Liquid Penetrant (LP) method is based on the capillarity and retention of dye substances in surface discontinuities. Its sensitivity depends on a number of factors which, if neglected, compromise the reliability of the test. Although simple and effective, its sensitivity can be compromised by several factors. This article explores the main interfering factors that affect the results and presents practical recommendations, based on ASTM E1417 , ISO 3452-1 and ABNT NBR NM 324 standards.

1. Main Interfering Factors in Penetrant Testing

Surface Contaminants

• These include : oils, greases, paints, oxidation, and various residues.
• Impact: They prevent liquid penetration and mask defects.
• How to avoid this: perform cleaning with compatible degreasers ( removers ) and visual inspection before applying the penetrant.

Inadequate Temperature

• Recommended temperature range: between 10°C and 50°C (according to ASTM E1417).
• Low temperatures increase viscosity, reducing penetration.
• High temperatures cause premature evaporation, impairing the effectiveness of the test.
• Solution: control the temperature of the part and the environment before and during the test.

Product unsuitable for the type of surface.

• Example of a common mistake: using highly sensitive fluorescent penetrants on rough surfaces, resulting in excessive background.
• Recommendation: select the type and sensitivity of the penetrant according to the texture and material of the part.

Incorrect Penetration Time

• Insufficient time: prevents the liquid from reaching the discontinuity.
• Excessive time: can cause smudging, increase visual noise, and make interpretation difficult.
• How to adjust: strictly follow the time recommended by the manufacturer and the technical standards.

Inadequate Penetrant Removal

• Problems caused: Inadequate cleaning: residual penetrant may mask defects. Excessive cleaning: may remove the penetrant from the discontinuity.
• Solution : Apply a removal technique according to the type of penetrant (water-washable, post-emulsifiable, or solvent-soluble).

Incorrect Application of Developer

• Common mistakes: Irregular or excessive application. Development time outside of standards.
• Good practices: respect the type of developer (dry, wet or non-aqueous) and the minimum development times, according to ASTM E1417.

2. Recommended Good Practices

• Use written and validated procedures (PVI or IT), in accordance with ISO 3452-1.
• Check the chemical compatibility between the materials of the part and the products used.
• Use calibrated UV-A light sources, following the ASTM E3022 standard.
• Perform the inspection in a controlled environment, preferably in suitable test booths, in accordance with ISO 3059.

Strict control of factors that interfere with the Penetrant Testing method is essential to guarantee reliable, traceable, and technically valid results. The correct selection of products, compliance with standards, and conducting the inspection under appropriate lighting and temperature conditions are indispensable requirements to ensure the effectiveness of the method and the integrity of the inspected structures.

Liquid penetrant (LP) inspection is widely used to detect surface-open discontinuities in welded joints. However, this type of inspection presents a recurring challenge: false positives. Often, indications observed during the test do not correspond to real defects, but rather to artifacts caused by inadequate surface conditions or process execution. Based on ASTM E1417, ISO 3452-1, and ABNT NBR 15808 standards, this article explores how to avoid these interpretative errors.

Sources of False Positives

Welded surfaces often exhibit roughness, weld spatter, and metallic residue that retains the penetrant unevenly, creating marks that can be mistaken for discontinuities. To avoid this, surface preparation is essential. Removing slag, oxides, and contaminants by light blasting or chemical cleaning according to ISO 8501-1 is a critical step before product application.

Another important factor is the correct choice of penetrant type and sensitivity. On rough surfaces, highly sensitive products can cause background saturation, making interpretation difficult. In these cases, the use of penetrants with intermediate sensitivity (level 2 or 3) is recommended. Furthermore, the lighting must comply with ISO 3059, especially in industrial environments with varying levels of natural light. White light above 1000 lux or UV-A light between 1000 and 5000 μW/cm² is essential to ensure adequate visibility of the indications.

Removing excess penetrant is also a critical step. If done excessively, it can erase a true indication. If insufficient, it can create a “colored background” and mask defects. The developer application must be uniform, and the development time must be respected according to the type used: dry, wet, or non-aqueous.

Finally, the inspector’s training makes all the difference. A professional trained according to ISO 9712 will have greater ability to distinguish between a true discontinuity and a surface artifact. Investing in training and continuous review of internal procedures contributes significantly to the quality and reliability of inspections.

Minimizing false positives in liquid penetrant testing (LP) of welds depends on three pillars: proper surface preparation, correct execution of the process, and professional qualification. These precautions increase the reliability of the test, reduce rework, and ensure more accurate decisions regarding the integrity of the welds being evaluated.

The accuracy of liquid penetrant (LP) weld inspection depends directly on the quality of surface preparation, the correct choice of penetrant, and the inspector’s experience. Standardizing the process according to international norms reduces the incidence of false positives and ensures greater reliability in acceptance or rejection decisions.