No matter what term you are familiar with for the process, whether it's plant turnaround or maintenance turnaround, it is unanimous among all that this is a delicate and crucial event for a production process.
The maintenance of valves in a plant is one of the key moments of this operation, and that's what we will discuss in this article today, produced by mechanical engineer Felipe Tonello Franco, commercial operations leader at Axpr.
What is a plant turnaround (or maintenance turnaround)?
Plant turnaround are scheduled occasions for equipment maintenance, which are essential elements for a company to remain competitive.
These plant turnarounds ensure that the business maintains its production volume, business performance, and that operational costs do not rise.
During a plant turnaround, there are different types of maintenance that can occur, such as corrective, preventive, and predictive maintenance, as well as detective maintenance, all related to the production line.
OK, so let's delve a little deeper into each type of maintenance that occurs during a plant turnaround.
Detective maintenance, for example, aims to capture faults that may escape regular maintenance, mainly acting on protective systems, and is carried out with the equipment in operation on the production line.
Moving on to predictive maintenance, we can translate it as a diagnosis of the lifespan of parts and equipment, especially those vital to a production line, closely monitoring their evolution for safe use until the limit of their lifespan.
In this type of maintenance, it is important to consider items such as value (costs), process safety, and equipment availability.
Preventive maintenance works, as the name suggests, in preventing potential problems with parts and equipment, such as valves, for example. In this modality, the main objective is to dilute (and in some cases, prevent) equipment breakdowns or performance failures under maintenance.
Want an example of preventive maintenance that is likely to happen in your daily life? The oil change of a car! This is because it is replaced at regular intervals, usually determined by the vehicle manufacturer, such as changing it every 6 months (or 5,000 km driven), etc.
In other words, the main focus of this type of maintenance is the relentless pursuit of avoiding (and reducing) the number of failures in parts and equipment, preventing problems, and maintaining absolute control over them.
And finally, we come to corrective maintenance, which improves the performance of equipment and its parts. We can consider it a step prior to preventive maintenance, ensuring greater reliability.
How is a plant turnaround planned?
The process of shutting down a plant is undoubtedly complex. This turnaround requires a lot of planning, preparation, and the support of qualified teams with experience in the field.
In the valve maintenance universe, we can highlight three main points for planning the turnaround:
- Installed Base Audit: This involves collecting location data, the need for access and vertical movement (scaffolding, cranes, etc.), as well as calibration data, measurements of casings, types of joints, among other information.
- Valve Diagnostics in the Line: That is, identifying and collecting information in the field to prioritize valves that need repairs (such as those with leaks, for example) to make data-based decisions on which valves should be maintained preventively.
- Inventory and Spare Parts Audit: In summary, an efficient turnaround has the necessary replacement parts available for maintenance but not in excess. A list of recommended spare parts and an interchangeability map are the first milestones for a good start.
And how to execute a plant turnaround?
A plant turnaround can be organized into stages to simplify management and make it more optimized. These stages can be summarized as:
- Conceptualization or initiation: the stage of the journey where the maintenance plan is created, containing rules and norms for the execution of the maintenance process.
- Planning or preparation: with data and information in hand, it's time to process and organize them into a plan that outlines the turnaround, defining its scope (which equipment and how they will be maintained - procedures) and the schedule of actions (such as days for execution, working hours, whether night activities will be included, among others).
It is also defined whether the turnaround will be carried out internally (known as in loco)meaning the service will be performed at the plant itself, or externally (known as in shop), in which case the equipment will need to be transported to the workshop of the contracted company.
I often make an analogy that it is preferable to perform surgery in a well-equipped ICU than in a Red Cross tent: the difference lies in the available procedures that can be performed in each.
In particular, for valve work, if the scope of the job requires reconstruction, performing maintenance on-site means bringing the mountain to the valve. However, a limited scope of work, such as fine adjustments, standard tests, and part replacements, can make on-site operation more economical.
- Execution: this is the process that actually performs maintenance and may contain stages before and after, such as pre- turnaround, turnaround, and post- turnaround (also known as start-up) .
In the pre-turnaround, construction sites are generally set up, equipment, tools, and labor are mobilized for execution. Also, in this stage, the team's safety integration is carried out, and badges that will provide access to the plant are prepared.
In the turnaround stage, maintenance services are performed according to the plan. As a curiosity, we call it a cold turnaround when the intervention in a specific equipment needs to be done in a short time, within 24 hours, for example.
In start-up or post- turnaround, the plant's start-up is monitored to verify if the interventions made have solved the equipment problems.
In the special case of safety valves, this stage usually includes online testing and calibration services performed with the valve assembled in the line, with a qualified professional, equipment designed specifically for this purpose, and a reliable database with critical internal valve measurements to be calibrated.
Also in this stage, resource demobilization and dismantling of the construction site are carried out, and it is in execution that the planned deadlines and costs are confirmed.
- Turnaround Closure: it is the end of the maintenance turnaround, with the delivery of the proposed scope and the return of the active production line. The unit's start is carried out, with a reduced team monitoring its start to observe the resumption of productive work and how maintenance will behave with the restart.
With this delivery made, the work does not stop: it's time to continue monitoring the entire post- turnaround life cycle, evaluating with clients how the next months of the maintained plant will unfold and, of course, monitoring the next maintenance windows that may occur in the future.
What should be observed in a maintenance turnaround?
Indeed, managing a maintenance turnaround is a considerable challenge for some companies: the volume of activities, employees, and information involved in a maintenance turnaround is complex and contains many details.
Well-executed turnaround planning, especially in the case of valve maintenance, observing the three main points I highlighted at the beginning of this article and that I allow myself to highlight again:
- The first would be the installed base audit.
- The second is to carry out the valve diagnostics in the line.
- The third is to perform the inventory and spare parts audit.
This generates savings because resources, such as spare parts, labor, and cranes, will be invested in valves that actually require interventions, making the operation more streamlined and fast.
In addition, when a valve maintenance turnaround occurs, first, the criticality in responding to a cold turnaround should be observed. In this case, where maintenance needs to be performed in a short time, the availability of parts and spare parts is crucial for the service to be completed on time.
The maintenance model needs to be defined. For example, if the client does not have the parts or spare parts for replacement during valve maintenance, resources will need to be mobilized for component recovery, such as:
- Materials and equipment for machining and welding.
- Machine for joint manufacturing, among some examples.
I emphasize again that turnaround planning is crucial because it will define the entire scope of how valve maintenance will occur.
Maintenance turnaround: real stories
Here at Axpr, we have a history of servicing valve maintenance in the main industrial segments, including petrochemicals, power plants, oil and gas, and pulp and paper, for example.
This history allows us to observe that turnaround for these segments mentioned generally have meticulous planning that includes the survey of the resources that will be necessary, such as spare parts.
One difference we can mention is that for the power plant segment, the planning tends to be executed in shorter periods because the plants have operations with greater seasonality than others, where the turnaround period is already defined well in advance.
For the industrial segments we serve, the scheduled turnaround is almost always comprehensive: in other words, in this type of turnaround, production is completely interrupted, with all equipment made available for maintenance.
Axpr works in partnership with factories, often participating in the conceptualization of the maintenance turnaround, assisting the client in defining the best turnaround model considering maintenance needs.
We can carry out internal plant turnaround (in loco), with services to be executed with our mobile workshop on the client's site, or external plant turnaround (in shop), where the valves are taken to our workshop for maintenance and then returned to the client's plant.
In both models, the same care and attention are applied to the valves.
Axpr, as a partner of Baker Hughes, which owns the Masoneilan and Consolidated brands, also plays a strong role in plant turnaround planning with clients, helping to survey the installed base, suggesting the necessary parts and spare parts, and assessing the resources needed for a successful plant turnaround.
A successful case I like to highlight, which is quite recent, is the service in an external plant turnaround, where we performed maintenance on 810 valves over 45 days under strict Petrobras inspection.
Maintaining existing equipment and installations in the industry is a fundamental factor for cost reduction, as this action is considered the most important activity in the sector that supports plant production, and is thus directly linked to all other production-related sectors.
Based on this, maintenance should not be seen as an unnecessary expense, but as an action capable of avoiding greater expenses in the future, when a turnaround may occur due to equipment failure, unexpectedly interrupting production and requiring solutions such as repair or even replacement of entire equipment.
For the company to remain competitive in the market, it is essential that all areas are focused, and the equipment, in our particular case, the valves, are operating in harmony.
If you want to learn more about Axpr's involvement in maintenance turnaround: and request our team's assistance, just click here!
