ENSURING IMPROVED ASSET INTEGRITY by Realtime Corrosion Monitoring and Steam Trap Monitoring

Monitoring of corrosion in a process pipelines have always been of paramount importance to ensure the integrity of plant assets. Similarly, steam traps play a very important role in ensuring steam quality, thereby the integrity of critical assets in the plant. It is common observation that many of the steamtraps become non-functional over a period of time and, more importantly, dangerously go unnoticed. While these are vital in ensuring asset integrity, and need continuous monitoring, it is also a highly demanding and challenging activity in the field, and a dream of many Integrity engineers to perform such asset monitoring remotely, that too, in realtime. Many vendors have been researching on this, and focusing on devising improved technology to ease the burden on such asset monitoring.

This paper intends to touch upon these two aspects of monitoring Asset Integrity – Realtime Corrosion monitoring and Realtime Steam Trap monitoring – as implemented in ADNOC-LNG. The paper shall highlight the importance of digitalization in the Asset Integrity Management - Pipeline Corrosion and Steam Trap monitoring - by means of implementing wireless technology and making the data available in remote workstations in realtime.

Topics covered:

Corrosion Monitoring: to move ahead from the conventional Corrosion management to the Wireless Ultrasonic Thickness gauging technology

Steam Trap Monitoring: to remotely monitor the healthiness of Steam Traps with a combination acoustic and temperature instruments.

Methods, Procedures, Process

Corrosion Monitoring: The installation at ADNOC-LNG covers 20 locations in OAG unit (Offshore Associated Gas unit, which has been identified as highly corrosion prone). The procedure involves installing UT sensors at the identified CMLs (Corrosion Monitoring Locations). These are easily installable onto the piping, and each sensor has a measurement footprint of about 1-2 cm2, which is similar to the manual ultrasound inspection method. The technology of ultrasound is well proven and has been used by Integrity engineers for manual inspections. These sensors employ wireless communication, and are powered by battery packs, which last through turnarounds. Doing away with the needs of power and signal cable, simplifies the installation process.

Steam trap monitoring system (20 locations identified in LNG Train-3 Utilities) also employs wireless acoustic and temperature sensors, which are installed on the steam trap piping. From the acoustics and based on the skin temperature measurements, the system identifies the health of the steam traps and determines which are Failed shut, or blow through.

Results, Observations, Conclusions

Corrosion Sensors: These UT sensors continue to give the wall thickness measurements of the exactly same point, over a period of time, which can help analyze the early onset of corrosion; unlike the manual UT measurements, where the repeatability and reproducibility of the readings are a challenge, as it is highly unlikely that the consecutive measurements taken after a gap of several months are exactly at the same location, and also it is highly person dependent. The corrosion data is transmitted over wireless, and made available to the desktop workstations of the Integrity Engineers.

Steam traps: Even though steam traps are audited in the plants on a regular basis, such surveys give the performance of the traps for that brief period of time (snapshot information), whereas, continuous steam trap monitoring provides information on the health of the traps on a continuous basis, that too, made available to the desktop workstations of the Operations/Maintenance engineers. It thus enables them to take early decision, and avoid costly failures of equipment/piping etc., and also, the avoid the loss of precious energy by ensuring timely maintenance.

Novel/Added Information

Wireless technology is easily scalable and hence, further additional sensors can be installed across the plant, without much capital outgo. With the thrust on Digitalization, our efforts should be focused on leveraging the benefits of technology.

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