ERW tube welding lines pt. II: extraordinary maintenance or revamping?

In his previous article, Eng. Grassino analyzed the choice between revamping an existing line and purchasing a new production line. In this issue, he explains the differences between extraordinary maintenance and revamping of an ERW tube welding line. This insight is crucial to understanding which option is more advantageous in various operational situations.

Extraordinary maintenance vs. revamping

The age of equipment deteriorates performance, which is also true for tube welding lines. However, many facilities have not consistently maintained their equipment over time for various reasons. In such cases, restoration can be very costly and yield only original, not state-of-the-art, performance. Therefore, it's essential to compare maintenance with revamping.

Let's first clarify the terms.

Extraordinary maintenance:

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• - Involves replacing or repairing worn or damaged components.
  - Restores the original operating conditions of the equipment.
  - Costs less than revamping and entails lower, more manageable industrial risks.
  
  

Revamping:

- Involves a complete overhaul and modernization of the equipment.
- Enhances performance, energy efficiency, and productivity.
- Requires a larger investment and involves higher industrial risks.

Evaluating maintenance status

Assessing a tube production plant's lack of profitability requires an accurate evaluation of its maintenance status. Many tube mills, particularly those with long histories and traditions, have aging equipment. Not all companies have managed to maintain consistent and efficient maintenance over time due to market fluctuations, strategy changes, or ownership transitions. If the maintenance level falls below certain standards, the tube mill risks becoming unprofitable.

Historical reports and tests can always reconstruct the actual capabilities of a refurbished plant. However, any extraordinary maintenance should be compared with a revamping that could further enhance the line's performance. The following outlines some steps in the decision-making process.

Decision criteria for maintenance or revamping

In some cases, the cost of extraordinary maintenance can be so significant that it becomes a strategically important decision. In these instances, it is crucial to compare this with revamping. The choice between extraordinary maintenance and revamping can be evaluated using this checklist:

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  ◆ Energy efficiency;
  ◆ Reduction in operating personnel;
  ◆ Increased productivity;
  ◆ Production range expansion.
•  

The checklist provides a general overview rather than exhaustive criteria. Each point must be evaluated for the results achievable through maintenance versus those through revamping, which alters the original design. Revamping scenarios are multiple and can vary in the extent of intervention on the equipment.

Cost analysis

Cost determination must be very precise for both extraordinary maintenance and revamping. In both cases, costs must be detailed to the smallest component and the simplest or shortest activity due to the high risk of errors in revamping estimates. Pre-engineering is necessary to verify dimensions and conduct a thorough process analysis of tube manufacturing. All implications of interventions on upstream and downstream process points must be carefully examined, considering both direct and indirect effects of revamping.

In these cases, it is recommended to consider even unlikely implications rather than neglect them. Undesired effects could even lead to project failure.

Riskiness of revamping interventions

Revamping interventions involve a very high level of industrial risk. Among all types of interventions, revamping is the riskiest! The solutions are specifically designed, often unique, and tested for the first time. Designers make fewer mistakes when replicating existing solutions, as these have already been used and any errors corrected. When the design solution requires deep adaptation, the likelihood of errors increases.

For this reason, not all line manufacturers propose revamping. In most cases, companies prefer to offer new plants since these projects are more likely to succeed, and designers are less uncertain. In comparison, a maintenance intervention is much less risky, as it involves replacing old parts with new ones without changing the design.

In the case of extraordinary maintenance on very old equipment, such as components from the '60s or '70s, direct replacement may not be possible due to changes in construction techniques and machining methods. The primary risks are the availability of reliable original drawings and the ability to conduct field surveys.

Summary

The cost of extraordinary maintenance is always lower than revamping, with more manageable industrial risks. However, maintenance alone does not guarantee market competitiveness. The decision-making process should consider the equipment's strategic relevance to the company, especially if financial resources are limited and must be allocated efficiently. If the equipment is strategically important, revamping is preferable, provided that industrial and technological risks are examined, evaluated, and mitigated to to maximize effectiveness.

About the author

Eng. Jacopo Grassino, with over 20 years of experience in the plant and steel industry, offers consultancy on cost optimization, production line start-ups, and team management.
Contact: +39 3396821463, [email protected], https://www.linkedin.com/in/jacopo-grassino/