Intelligent Servicing of Valves During Aging Plant Shutdowns
Shutdowns, turnarounds and outages (STOs) play a major role in plant safety, performance, reliability and profitability.
More than half of plants in the world are older than 20 years; 40% are older than 30 years; and 30% are older than 40 years. By comparison, in the mature industrial region of Europe, the statistics show that 60% of plants are older than 20 years; half are older than 30 years; and 40% are older than 40 years. (Source: Industrial Info Resources).
Maintenance and service personnel in all these plants face numerous challenges, especially in aging facilities. Those challenges include:
- Reducing operational expenses
- Improving safety and reliability (to avoid unplanned shutdowns)
- Adhering to stringent emissions regulations
- Addressing the decline in personnel experience and capabilities
- How to improve the productivity of aging assets
- Loss of meaningful data through lack of quality maintenance records
- The obsolescence of products and difficulty in obtaining spares
- The lack of standardization among manufacturers and products.
Intelligent servicing of valves and controls can overcome many of the issues these aging plants face.
CRITICAL FACTORS FOR SUCCESS
According to data provided by Asset Performance Network, two-thirds of STOs are unsuccessful, meaning they result in cost overruns and lost production. Among the key factors that cause these problems is lack of detailed planning, a scope of work that is too broad and poor STO execution because of the lack of skills and inadequate documentation.
End users can overcome these issues with help from qualified suppliers through data-driven planning, use of mobility tools and asset integrity management.
Mobility tools provide easily accessible centralized data, which enables safer, more efficient STO. What’s more, combining high-level, in-person service with dynamic mobile applications allows plant personnel to optimize the time and budget allocated for STOs. This is because the mobility tools eliminate or reduce the need for paper recordkeeping while equipping plant personnel with an easier, more efficient way to store, access and analyze the data. Armed with quality data, the end user is better prepared to make informed decisions and take calculated actions.
The process begins with a thorough walk down, which is key to defining and prioritizing STO scope. Walk-down applications now offered by many reputable suppliers leverage mobile workflow technology to improve asset data collection from a variety of devices. Such applications also evaluate the overall health of assets while revealing ways to improve field service productivity. Using such applications is not essential; in fact, many plants still use spreadsheets for the walk-down process. However, applications allow the data to be digitized and centralized for easier analysis. They also allow quicker access to historical tag information, which can include equipment health conditions. Such access allows more data-driven decisions to occur. Whichever method is used, assessing the condition of the valves through the walk-down process is a critical step in effective STO planning.
Asset tagging allows safe, fast identification during walk downs. Plant personnel can track their assets with an intrinsically safe (FM-, CSA- and ATEX-certified) rugged radio frequency identification tag affixed to valves and other equipment. These tags keep workers at a safe distance from hot or other challenging process conditions while gathering information digitally instead of requiring scaffolding climbing or entry into confined and hazardous spaces. The tags contain key service information—for example, the date the equipment was last serviced or inspected as well as when it’s due to be serviced or inspected again. Meanwhile, end users can optimize asset management by tracking equipment locations and recording repair notes from these tags. They also can update information as components and service requirements change.
To integrate the information, the practice of asset integrity management can be used. This practice is an integrated solution that allows monitoring and managing of all assets (including valves, actuators and controls) from one point. This helps plant personnel mitigate risks, reduce costs and optimize performance during STOs.
Key components of an asset integrity management solution include inventory management, shutdown planning and risk-based inspections (RBI). It also can include compliance management data, asset tracking information, business intelligence and root cause failure analyses. By using asset integrity management, end users have visibility into all assets from a single point with 24-hour access. Those with access can diagnose failures and take corrective actions and support STO planning. (Figure 2)
Predictive and preventive maintenance needs are addressed through the powerful tool of shutdown planning. As part of that process, plant personnel work with suppliers to lay out each of the activities that will be performed during a turnaround. These activities can include defining the scope of work, scheduling the STO activities that are needed, and procuring the parts and replacements that will be required for maintenance and repair.
The scope of work is determined through the previously addressed walk-down process. Planning for the shutdown then allows more knowledge-based purchasing of parts or replacement parts.
RBI is the methodology used to determine optimal repair cycles for each asset. It’s based on an asset failure probability/consequence matrix. RBI calculations use historic repair observations to accurately determine failure probability. They link customer-defined failure consequences with the asset failure probability to derive repair cycles, then repair cycles are extended or shortened as appropriate.
The result is a reduction of risks because repair or replacement happens before failure and a reduction in costs that might result from extended repair intervals.
A half-century-old, mid-sized refinery in the United Kingdom was able to extend its repair intervals on pressure-relief valves (PRVs) from every 23 months to 53 months using asset integrity management and risk-based inspection. The end user had 3,000 PRVs that used an asset integrity management solution starting in 1998. RBI and root cause failure analysis processes effectively managed valve repair frequency.
Besides extending repair from 23 to 53 months, key results were a reduction in the number of repairs by 18%, a 35% reduction in annual PRV repair and optimization of PRV spare parts inventory through effective predictive maintenance strategies. (Figures 3 and 4)
Case Study Two: Turnaround in four-decades-old chemical plant
A chemical plant in Europe was in operation for about 40 years. In 2016, the end user faced its largest STO in five years. Many of the plant’s valves were old, worn, damaged or obsolete. The plant needed to address repair, maintenance or replacement of 250 safety relief valves, 180 control valves and 80 manual valves.
The asset integrity management deployment in the plant proved to be effective in allowing plant personnel and the supplier of choice to know the asset repair history and current conditions of this equipment, identifying old or obsolete valves and procuring replacement products. It also allowed preparation for extra activities needed such as welding, workshop repairs and other activities and built an awareness of valves that will need to be replaced at the next STO, thus establishing a continuous improvement STO process.
The end user achieved completion of 100% of the planned work as well as 100% health, safety and environmental compliance, zero reworking and on-schedule completion of the process.
End users that adopt a best practices approach to intelligent servicing of valves can better achieve STO goals and secure a solid position as a top quartile performer. Effective planning and thoroughly defining the scope of work between the user and a chosen supplier are keys to STO success.
Asset integrity management improves plant knowledge and reliability and allows planning for successful STOs as well as a reduction in unplanned shutdowns.
When the right tools are used to manage and maintain equipment effectively, aging plants can perform as well as newer plants.
JODI JOHNSON is perfect execution director at Emerson Automation Solutions (www.emerson.com). Reach her at Jodi.Johnson@Emerson.com. NAVÈ ORGAD is lifecycle services director for Emerson Automation Solutions. Reach him at Nave.Orgad@Emerson.com.
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