PNL QUALITY EXAMINER

PNL continues to strengthen its role as a trusted partner in industrial reliability with a comprehensive suite of Asset Integrity Services designed to keep critical equipment safe, compliant, and performing at peak efficiency. From large above ground storage tanks to high pressure piping systems, PNL’s inspection teams support clients through every stage of an asset’s lifecycle.

In Service Inspections: Keeping Operations Running Safely

PNL’s in service inspection programs allow facilities to maintain production while ensuring equipment remains structurally sound. Using advanced nondestructive testing (NDT) methods—including ultrasonic testing, magnetic particle inspection, radiography, and corrosion mapping—PNL technicians evaluate the condition of tanks, pressure vessels, and piping systems without interrupting operations.

These inspections help identify early signs of degradation such as wall thinning, cracking, weld defects, and corrosion under insulation. By detecting issues before they escalate, PNL enables clients to plan maintenance proactively, reduce unplanned downtime, and extend the service life of critical assets.

Out of Service Inspections: Deep Evaluation for Long Term Reliability

When equipment is taken offline for scheduled maintenance or regulatory compliance, PNL performs detailed out of service inspections that provide a complete picture of asset health. These evaluations include internal visual examinations, structural assessments, coating evaluations, and comprehensive NDT testing.

Out of service inspections allow PNL to access areas not visible during operation, ensuring that every component—from shell plates and weld seams to nozzles and support structures—is thoroughly assessed. The result is a clear understanding of current condition, remaining life, and any required repairs.

Actionable Repair Recommendations

Beyond identifying issues, PNL delivers practical, data driven repair recommendations tailored to each client’s operational needs and regulatory requirements. Whether it’s recommending weld repairs, component replacements, coating upgrades, or changes to inspection intervals, PNL’s engineering and inspection teams work together to provide solutions that enhance safety and reliability.

A Commitment to Safety and Performance

With a focus on precision, compliance, and customer partnership, PNL’s Asset Integrity Services help facilities operate with confidence. By combining advanced inspection technology with experienced personnel and clear reporting, PNL ensures that industrial assets remain safe, efficient, and ready for the demands of modern operations.

Ensuring the long-term reliability of industrial tanks, pressure vessels, and piping systems requires more than routine visual checks. Today’s facilities rely on advanced nondestructive testing (NDT) technologies that reveal hidden flaws, quantify material degradation, and support data driven maintenance decisions. PNL continues to expand its capabilities in this area, offering a suite of cutting-edge inspection tools designed to evaluate asset integrity with precision and efficiency.

Magnetic Flux Leakage (MFL): High Speed Detection of Corrosion and Wall Loss

Magnetic Flux Leakage is a powerful technique widely used for inspecting storage tanks and pipelines. By magnetizing steel components and measuring disturbances in the magnetic field, MFL systems can quickly identify areas of corrosion, pitting, and metal loss.

• Ideal for tank floors, pipelines, and large surface areas
• Provides rapid scanning with high sensitivity
• Generates detailed maps of defect locations and severity

MFL helps operators prioritize repairs and plan maintenance with confidence, especially in high risk or high throughput environments.

Guided Wave Testing: Long Range Screening for Piping Systems

Guided Wave technology allows inspectors to evaluate long stretches of piping from a single test location. Low frequency ultrasonic waves travel along the pipe wall, reflecting off changes in geometry or material condition.

• Effective for insulated, buried, or elevated piping
• Detects corrosion, weld defects, and localized thinning
• Reduces the need for extensive insulation removal or excavation

This method is particularly valuable for identifying problem areas early, enabling targeted follow up inspections and minimizing operational disruption.

Ultrasonic Mapping Systems – Tank Crawlers: Automated Precision for Large Surfaces

Automated ultrasonic crawlers bring a new level of accuracy and efficiency to tank and vessel inspections. These remotely operated systems traverse vertical or horizontal surfaces while collecting high resolution thickness data.

• Provides full coverage corrosion mapping
• Reduces confined space entry and improves safety
• Offers repeatable, digital datasets for trending and lifecycle analysis

Tank crawlers are essential for assessing shell plates, weld seams, and other critical areas where manual inspection is difficult or hazardous.

LIDAR Systems: High-Definition Structural Modeling

Light Detection and Ranging (LIDAR) technology uses laser scanning to create precise 3D models of tanks, vessels, and piping systems. These models capture geometric deformation, settlement, and structural anomalies with exceptional clarity.

• Ideal for measuring tank roundness, tilt, and settlement
• Supports engineering assessments and fitness for service evaluations
• Produces digital twins for long term monitoring
• LIDAR enhances decision making by providing a visual, measurable record of asset condition over time.
• Metallurgical Evaluations: Understanding Material Behavior and Failure Mechanisms

Beyond field inspections, metallurgical evaluations provide deep insight into the condition of tank, vessel, and piping components. Laboratory analysis can reveal the root causes of degradation or failures and help predict future performance.

• Identifies cracking mechanisms, corrosion types, and material defects
• Supports failure analysis and repair planning
• Ensures compliance with industry codes and material specifications

Metallurgical testing complements NDT by explaining why damage occurs, not just where it is found.  We often correlate results of NDT with metallurgical results to create nondestructive testing plans so that damage mechanisms can be identified and assessed before failures occur in other equipment operating in similar conditions.  

Advancing Asset Integrity Through Technology

By integrating these advanced nondestructive test methods, PNL delivers comprehensive asset integrity assessments that help clients operate safely, efficiently, and with full regulatory compliance. From rapid screening tools to high resolution mapping and laboratory analysis, PNL’s technology portfolio ensures that critical infrastructure remains reliable throughout its service life.

A safety program for entering hazardous environments in a tank or vessel must ensure that all potential risks are identified, controlled, and continuously monitored to protect personnel from injury or fatality. Prior to entry, a formal hazard assessment shall be conducted to identify atmospheric, physical, chemical, and biological hazards, including oxygen deficiency or enrichment, toxic or flammable gases, residual chemicals, engulfment hazards, and mechanical or electrical energy sources. The tank or vessel shall be classified as a confined space or permit-required confined space as applicable, and a written entry permit must be completed and authorized before any work begins.

All energy sources connected to the tank or vessel must be isolated, locked, and tagged out, including piping, valves, agitators, heaters, and electrical systems. The space shall be thoroughly cleaned, drained, purged, and ventilated to remove hazardous residues and vapors. Atmospheric testing must be performed by a trained and qualified person using calibrated instruments to verify acceptable oxygen levels, flammable gas concentrations below permissible limits, and toxic substances below occupational exposure limits. Continuous atmospheric monitoring shall be maintained for the duration of entry, with immediate evacuation required if unsafe conditions are detected.

Only trained and authorized personnel may participate in tank or vessel entry. Each entry team shall consist of authorized entrants, a dedicated attendant stationed outside the space, and an entry supervisor responsible for oversight and permit control. Entrants shall wear appropriate personal protective equipment based on the hazard assessment, which may include respiratory protection, chemical-resistant clothing, gloves, eye and face protection, and intrinsically safe lighting. Communication between entrants and the attendant must be maintained at all times through verbal, visual, or electronic means.

Rescue and emergency response procedures must be established prior to entry, with rescue equipment such as retrieval lines, harnesses, and tripods readily available. Non-entry rescue shall be the primary method whenever feasible, and rescue personnel must be trained and capable of responding without delay. The entry supervisor shall ensure that emergency services are notified as required and that all personnel understand evacuation signals and procedures. Upon completion of work, the space shall be exited safely, the permit closed, and the tank or vessel returned to normal service in accordance with site procedures.

It is the responsibility of each and every person involved in a tank entry – owners, contractors, and inspection companies and their personnel - to ensure individuals entering confined spaces understand the hazards and enter in a safe and controlled manner.

Maintaining the integrity of tanks, pressure vessels, and piping systems is not just good practice — it’s a regulatory and safety imperative. Industry codes such as API 653, API 510, and API 570 establish clear criteria for when repairs must be performed to keep equipment operating safely and in compliance. Understanding these triggers helps facilities plan maintenance activities and avoid costly unplanned outages.  While the API 653, 510, and 570 codes were primarily created to manage in-service inspections and repairs for petroleum-based assets, the codes have been adopted by and are applicable to other industries including water and chemical storage, steam and chemical processing applications, and waste product applications.  

Repair Requirements

The API codes outline the conditions under which storage tanks, pressure vessels, and piping systems must be repaired to maintain structural integrity and prevent product release. Test and inspection data is compared the original code of construction to determined integrity.  Data from multiple inspections is used to assess and/or monitor in-service damage and calculate current stress conditions and deterioration rates based on operating parameters.  Repairs are typically required when inspections reveal:

For Tanks:

• Excessive corrosion or wall thinning beyond allowable limits
• Cracks, weld defects, or deformation that compromise shell or floor integrity
• Settlement or out of roundness that affects stability or serviceability
• Nozzle or manway damage that threatens leak tightness or structural performance

When these conditions are identified, API 653 requires repairs to be performed by qualified personnel following approved procedures. Repair plans often include weld restoration, floor plate replacement, shell patching, or structural reinforcement. Engineering evaluation may also be required to confirm fitness for service.

For Pressure Vessels:

• Wall loss that reduces thickness below the minimum allowable
• Cracking or embrittlement in welds, heat affected zones, or base metal
• Distortion or bulging caused by overpressure or thermal cycling
• Corrosion mechanisms such as pitting, hydrogen damage, or stress corrosion cracking

API 510 emphasizes engineering assessment, proper welding procedures, and post repair inspection. Repairs may involve weld buildup, component replacement, or installation of reinforcing pads. All repairs must be documented and verified to meet code requirements before the vessel is returned to service.

For Piping Systems:

• Localized or general corrosion that reduces wall thickness below code limits
• Cracks, leaks, or mechanical damage at welds, supports, or fittings
• Corrosion under insulation (CUI) or soil to air interface degradation
• Support failures or misalignment that create excessive stress

Repairs under API 570 may include weld repairs, spool replacement, clamp installation, or rerouting of piping. The code also stresses the importance of qualified welders, approved procedures, and appropriate NDT to validate repair quality.

The Role of Inspection and Engineering in Repair Decisions

Across all three codes, one theme is consistent: repairs must be based on sound inspection data and engineering judgment. Nondestructive testing methods — such as ultrasonic thickness readings, magnetic particle inspection, radiography, and corrosion mapping — provide the information needed to determine whether a component is still fit for service or requires corrective action.

Engineering evaluations, including fitness for service assessments, help determine whether repairs are mandatory, optional, or if continued operation is acceptable with monitoring.  PNL provides testing and inspection services by API certified individuals and helps make fitness for service recommendations using sound engineering principles and judgements by registered professional engineers.  

Ensuring Safe, Compliant, and Reliable Operation

Repairs are not simply a response to damage — they are a critical part of maintaining asset integrity and regulatory compliance. By following the requirements of API 653, API 510, and API 570, facilities can ensure that tanks, vessels, and piping systems remain safe, reliable, and ready for continued service.

If your company is in need of asset inspections, please contact our office and we will provide you with a quote to provide integrity services.

Phone: (602) 431-8887 or 1-800-602-1180

Email: pnltest@pnltest.com