Articles

Many of the component or system failures that happen in many industries are related to materials selection or material quality issues. Owners and operators must ensure that materials and components meet standards and are suitable for use in service. Third-party independent verification (reviews and inspections) plays an important role in ensuring confidence in material selection, regulatory compliance and safe operation of assets.
Proper verification provides valuable information on a material’s ability to perform and endure. Materials verification is a fundamental and essential element in analyzing component properties and can be accomplished through a multitude of methods and techniques.
In the United States, verification of materials essential to the inspection and integrity of pipeline assets is required for compliance with 49 CFR § 192.624 and
re-verification of Maximum Allowable Operating Pressure (MAOP).
Pipeline operators establish a pipeline integrity management plan based on reliable pipeline material characteristic information and use it for MAOP verification and fitness-for-service. It can also be used to verify the feasibility and safety of hydrogen pipes for conversion to a cleaner energy source.
In accordance with PHMSA §192.607 (Pipeline Material Characteristics and Property Verification), FI provide accurate and reliable material verification to ensure records are traceable, verifiable, and complete (TVC).
FI enables pipeline operators to make better-informed decisions that improve safety, ensure quality, enhance performance, and comply with ever-changing regulatory requirements. FI enables safe, accurate and efficient field data collection without disrupting pipeline and utility operations.

Fitness-for-Service (FFS) is a methodology to determine the adequacy of a structure for continued service when it contains a flaw or is operating in a particular condition where there is risk of failure. The benefits of FFS are:

• ∙ Operational and maintenance reduced costs by reducing the requirement for unnecessary repair and replacement
• ∙ Maintain mechanical integrity of assets
• ∙ Extension of assets service life and reduction of capital expenditure
• ∙ Compliance of regulation for a safe operation

In industrial production facilities, various types of critical production assets are subjected to a range of operating conditions and subsequent potential damage mechanisms. Among the critical assets in question are for instance: pressure vessels (reactors, heat exchangers, separators), piping systems, storage tanks, pipelines, valves and pumps. Over time, these production relevant assets may undergo gradual weakening and develop defects or experience degradation due to factors such as corrosion, fatigue, cracking, erosion, pitting or other damage mechanisms. The FFS assessment is performed to evaluate the impact of these defects or damages on the structural integrity, safety and remaining useful life of the equipment. It involves a systematic analysis that considers the type, size, location and characteristics of the flaws, as well as the operating conditions and applied loads on the equipment and the equipment-specific geometry. The assessment follows relevant industry codes, standards, and guidelines to determine whether the equipment can continue to operate safely or whether repair, replacement or mitigation measures are required.

Integrity diagnosis and assessment of industrial structures and structural components are important and necessary, since unexpected failure can cause extensive damage. Managing structural integrity requires consideration of the presence of defects in the structure, design stresses, and material properties. Structural defects are often caused by changes in the mechanical properties of the material due to deterioration or embrittlement. Therefore, it is necessary to measure the in-situ mechanical properties of structural components in operation to assess structural integrity. The mechanical properties of the materials are fundamental parameters in integrity assessment. For the safe use and integrity management of industrial facilities, it is necessary to analyze and assess through regular diagnosis of material properties. Also, it is necessary to secure the reliability of materials and parts based on the application of appropriate property evaluation techniques. The instrumented indentation testing (IIT) has been developed and widely utilized as one of the most versatile and practical means for evaluating mechanical properties such as hardness, tensile properties (i.e., yield strength (YS) and ultimate tensile strength (UTS)), fracture toughness and residual stress. IIT accomplishes this by measuring a material’s response to a series of smallscale surface indentations and then relating this indentation response to its stress-strain properties. It can be applied directly to small-scale and localized sections in industrial structures and structural components since specimen preparation is very easy and the experimental procedure is nondestructive. This method is particularly desirable for those applications where it is difficult to experimentally determine the mechanical properties using stress–strain data obtained from coupon specimens.

1. 1. Using lifetime data
   Using lifetime data to estimate RUL involves analyzing historical data about an asset's performance, failures, and maintenance to predict how long it will function before needing significant repair or replacement. Here is an example :
   ∙ Aircraft maintenance: Airlines collect vast amounts of data on their aircraft's performance, including engine health, flight patterns, and maintenance history.
   By analyzing this lifetime data, engineers can estimate when critical components like engines or landing gear might fail, allowing for proactive maintenance to avoid costly downtime.
2. 2. Using run-to-failure (RTF) histories
   Using RTF histories to calculate RUL involves analyzing data from assets that have operated until failure to predict how much longer similar assets might last before they fail. Here is an example :
   ∙ Automotive components: Manufacturers study the performance of automotive parts like brakes, tires, and batteries. By analyzing RTF histories, they can estimate how long these parts typically last under various usage conditions, helping drivers plan for replacements before failures occur.
3. 3. Using a threshold value on an asset
   Using a threshold value and a condition indicator to calculate RUL involves setting a predefined limit (threshold value) for a specific condition indicator of an asset. When the condition indicator reaches or exceeds this threshold, it signals that the asset is approaching a critical state, and the RUL can be estimated based on this information. Here is an example:
   ∙ Vibration monitoring in rotating machinery: For equipment like motors, pumps, and turbines, vibration is a critical condition indicator. A vibration sensor is often used on this equipment, and a threshold value for acceptable vibration levels is set based on historical data and manufacturer recommendations.
   When vibration levels exceed this threshold, it indicates potential wear or imbalance, and the RUL can be estimated using predictive models that correlate vibration levels with remaining life.

Remaining useful life (RUL) refers to the estimated amount of time an asset has until it becomes unusable or requires replacement. RUL is commonly used in predictive maintenance to determine when maintenance activities need to be performed on equipment to extend its lifespan and ensure reliable performance. RUL prediction plays a significant role in integrity management across the fields of machinery, civil engineering, aerospace, and energy.

Predictive maintenance of production lines is important to early detect possible defects and thus identify and apply the required maintenance activities to avoid possible breakdowns. An important concern in predictive maintenance is the prediction of RUL, which is an estimate of the number of remaining years that a component in a production line is estimated to be able to function in accordance with its intended purpose before warranting replacement.

While RUL and the overall life of an asset may seem similar, they differ in some significant ways. The overall life of an asset refers to the total duration of time that an asset is expected to remain useful. This is typically measured in years. RUL, on the other hand, is an estimation of the remaining time until an asset fails or can no longer perform its intended function and may be measured in days or hours.

Predictive maintenance that utilizes RUL calculations offers several benefits, including:

• ∙ Reduced downtime and equipment failure
• ∙ Increased longevity of assets
• ∙ Lower maintenance and repair costs
• ∙ Greater predictability and better asset management
• ∙ Improved safety for workers and equipment users

The remaining useful life of an asset is often more important than the overall life of an asset, as it helps maintenance teams identify the optimal time to perform maintenance activities to mitigate the risk of failure.

In modern engineering, organizations must consider reliability and integrity across the full lifecycle of critical assets. Ensuring that all equipment is properly designed, built, installed, operated, and maintained will Prevent loss of containment and structural instability.
The purpose of an Asset Integrity Management System (AIMS) is to ensure that an asset will perform its required functions effectively and efficiently whilst maintaining asset value and protecting people, the environment and company reputation.
AIMS should define and monitor integrity requirements through every stage of the asset life cycle. These requirements should be defined at the design stage and then monitored and maintained throughout operational life until eventually decommissioning.
Asset criticality assessments identify the most critical equipment to organization by risk ranking each asset and comparing the impact to business objectives, personnel safety, and environmental damage. It provides asset lists with criticality rankings that can be used to develop asset reliability strategies, inspection planning, and maintenance schedules.
An effective AIMS will improve plant reliability and safety whilst reducing unplanned maintenance and repair costs. This will optimize both OPEX costs and the commercial performance of the assets.
FI’s AIMS services include equipment mechanical integrity, structural integrity management, RBI for structures, life extension studies, and pipeline integrity management.
AIMS is designed to improve safety, environmental impact, and reliability. Continuously improving the AIMS program will help the facility proactively evolve with changes in technology and industry.

A standard is a document that is established by consensus and approved by a recognized body. The document should provide common and repeated uses, rules, guidelines, or characteristics for activities or their results. The documents aim to the achievement of the best point of order in each context.
An international standard is a technical standard developed by one or more international standards organizations. The most prominent such organizations are the International Organization for Standardization (ISO), the International Telecommunication Union (ITU) and the International Electrotechnical Commission (IEC). The ISO standard establishment process generally consists of six steps (preliminary and proposal stage, preparatory stage, committee stage, enquire stage, approval stage, publication stage) from proposal to publication. The details are as follows.

• - NP/NWIP: Approval of the New Work Item Proposal by meeting of the relevant technical committee or subcommittee or by written vote for three months.
• - WD: Steps to create a working draft of an international standard.
• - CD: The stage where consensus must be reached among committee members on the committee draft
• - DIS/CDV: The stage in which the Draft International Standard prepared by completing the committee stage – in the case of IEC, the Committee Draft for Vote – is voted on under the supervision of the Central Secretariat
• - FDIS: A two-month ballot circulation phase at the Central Secretariat with the Final Draft International Standard.
• - IS: The stage in which an international standard is published by the central secretariat after a final review with the secretary of the relevant committee