Recent in Engineering Science and Technology

A Review on Strengthening Asset Integrity Management through Risk-Based Inspection In Hydrocarbon Piping Systems

2026-06-27T00:13:48+07:00

Hydrocarbon piping systems are critical assets in oil and gas facilities because they operate under pressure, temperature, fluid variability, and corrosive environments that can accelerate material degradation. This study develops a risk-based integrity evaluation framework for hydrocarbon piping systems by integrating corrosion rate assessment, remaining life estimation, and Risk-Based Inspection (RBI) prioritization within an Asset Integrity Management (AIM) perspective. A quantitative case study was conducted using 2025 inspection data from hydrocarbon and utility piping systems at PT X. The evaluation followed the principles of API RP 580 and API RP 581 and used ultrasonic thickness measurement, actual wall thickness, minimum required thickness, corrosion rate, remaining life, Probability of Failure (PoF), Consequence of Failure (CoF), and risk ranking. The results show that most piping systems were categorized as Very Low Risk, while several lines remained in the Medium Risk category. Utility Water Piping had the highest corrosion rate of 0.253 mmpy and the shortest remaining life of 8 years. Hydrocarbon Gas Piping had a lower corrosion rate of 0.076 mmpy and a remaining life of 38 years. The proposed framework strengthens inspection prioritization, risk-based maintenance, and long-term AIM implementation.

Failure Analysis of Economizer Tube Leakage Caused by Localized Internal Corrosion at Weld-Root Regions

2026-07-02T14:24:41+07:00

Economizer tube leakage is a common failure in industrial boiler systems and may result in unplanned shutdowns and significant production losses. This study investigates the leakage failure of ASTM A210 Grade C economizer tubes removed from a pulp and paper boiler after long-term service. The investigation combined field inspection, wall-thickness measurements, chemical composition analysis, hardness testing, metallography, and SEM–EDS characterization to determine the degradation mechanism responsible for leakage. Leakage was detected in Tube Row 99 and Tube Row 185 near circumferential and stopper-weld locations. Visual examination revealed that damage was concentrated in the weld-root vicinity, whereas adjacent tube sections remained comparatively unaffected. Thickness measurements showed severe localized wall loss, with the minimum remaining thickness decreasing from 3.00 mm to 1.85 mm. Chemical composition analysis confirmed compliance with ASTM A210 Grade C requirements, while hardness testing showed no evidence of abnormal hardening or thermal degradation. Metallographic examination revealed oxide-layer deterioration and corrosion penetration adjacent to the weld-root interface. SEM–EDS analysis identified corrosion products dominated by iron oxides, confirming an internally initiated corrosion process. Available operating records indicated fluctuations in dissolved oxygen concentration, although the monitoring data were incomplete. The results indicate that excessive weld-root penetration promoted deposit retention and localized environmental variations, creating conditions favorable for oxide-layer deterioration and localized internal corrosion. Progressive wall thinning adjacent to the weld-root region subsequently led to through-wall perforation and leakage. The failure mechanism was identified as weld-root-associated localized internal corrosion, while dissolved oxygen fluctuations were considered a contributing factor to corrosion propagation rather than the primary cause of failure.

Design of a Heavy-Duty Manual Turntable for Heavy Material Handling Activities to Reduce the Potential Risk of Musculoskeletal Disorders (MSDs)

2026-06-18T06:37:27+07:00

Heavy material handling and rotation activities in the fabrication area are still performed manually using a conventional worktable without a material rotation system. This condition requires the observed operator to bend, twist the body, and repeatedly lift and reposition the material during the work process. These non-neutral working postures have the potential to cause Musculoskeletal Disorders (MSDs), particularly in the neck, shoulders, lower back, arms, and wrists due to excessive and repetitive physical loading. Therefore, this study aims to analyze ergonomic risks in heavy material handling activities and design a Heavy-Duty Manual Turntable to improve operator working posture. The methods used include field observation, work posture documentation, Nordic Body Map (NBM) analysis, posture angle measurement, ergonomic evaluation using Rapid Upper Limb Assessment (RULA) and Rapid Entire Body Assessment (REBA), anthropometric analysis, CAD-based design simulation, and simple biomechanical analysis. The NBM screening was completed by one observed operator and identified complaints in the neck, shoulders, lower back, upper arms, wrists, and lower legs. The initial condition had a RULA score of 6–7 and a REBA score of 9–11. The proposed solution is a Heavy-Duty Manual Turntable Model VP1-R with 360° rotational capability and an adjustable working height. Based on the proposed posture simulation, the estimated RULA score decreased to 2–3 and the estimated REBA score decreased to 2–3. The simplified biomechanical comparison also indicated an approximately 45% reduction in the lower-back moment. Because the post-design assessment was based on CAD simulation and not on a fabricated prototype, these results should be interpreted as preliminary design estimates. This study presents an ergonomic assistive-device design that can be used as a basis for prototype development and field testing.