In this article, I want to provide you with information about maintenance needs in the industry, as well as show you the types of maintenance that are currently practiced. In the end, you will better understand how different types of maintenance are applied and why in some cases one way is better than the other in terms of cost, safety and productivity.
Why Do Maintenance?
Over time, each part of the machine or equipment will wear out during operation. These abrasions can be of the most diverse types as abrasion, corrosion, erosion, aging, contamination, damage, malfunction, etc. The wear has a limit on each equipment and every time this limit is exceeded, the equipment breaks. The only activity that is able to correct these conditions is the maintenance, which manages to restore the wear an initial condition of the equipment, keeping them at satisfactory levels that guarantee the operation of the plant.
In continuous process industry, maintenance becomes critical besides the eam because a pause in the process costs a lot of money, once the equipment breaks down, it takes considerable time to re-establish the process cycle. In many cases still, during the restoration, much raw material is consumed without producing anything. As an example, we can cite the fuel that is consumed by the steam generator during startup operation of a power plant that does not generate until the required quality of steam generated is ideal for power generation.
The different types of maintenance, although they differ in their aspects, have some common objectives, among which we can mention:
– Ensure the availability of quality equipment in the services;
– Correct lost efficiencies in order to provide the lowest cost of production;
– Ensure the safety of operational equipment and the safety of people working in the company.
The 6 Types of Maintenance
Traditionally, we can list 6 types of maintenance, which are differentiated by the nature of the activities, which may or may not be planned. In the Figure below, we can see how maintenance types are defined.
1 – Preventive Maintenance
Preventive maintenance, among the types of maintenance, stands out by maintaining the equipment level, scheduling periodic interventions in order to reduce equipment deterioration. Preventive maintenance combines methods based on time and conditions to keep equipment functioning and from interventions, it can maintain the performance of structural materials, prevent corrosion, fatigue and other forms of deterioration. An important feature of this type of maintenance is that the inspection or intervention in the equipment is done periodically even if it does not problems.
2 – Stop Maintenance
Shutdown maintenance is also called maintenance for improvement or maintenance prevention. They are stops or great stops of equipment that have as objective to make that they reach the state of new. Revisions and repairs are made to all items to ensure, with high probability, good performance of the equipment over a long period of time.
3 – Corrective Maintenance
The set of activities aimed at correcting defects found in different equipment is the characteristic of corrective maintenance, where it begins with the users or operators of the equipment reporting defects and communicating to the planning of the maintenance department, which in turn, provides a specialized technician to make the correct correction of the problem.
4 – Break Maintenance
Unlike the type of planned maintenance, the maintenance of breakage is among the types of maintenance where there is no planning of activities. This means that the intention is to let the equipment operate to the same break so that it will be repaired. Breakage maintenance is applied when failures do not significantly affect the operation, production or do not generate any financial loss.
5 – Time Based Maintenance
Time-based maintenance consists of visual inspection, lubrication, cleaning of equipment and replacement of parts to prevent sudden failures and process problems. These types of maintenance generally do not require specialization and can be performed by the operators themselves through basic training. In the TBM, it is part of the autonomous maintenance and specialized maintenance activities.
6 – Condition Based Maintenance
As the name implies, condition-based maintenance is triggered by actual equipment conditions rather than by the occurrence of a predetermined time interval. The main condition based maintenance tools used here are based on predictive maintenance and they consist of collecting and reporting information based on certain known values of the equipment. Some examples are: temperature collection through thermograph, analysis of vibration through the use of accelerometers and analysis of oil quality in laboratories. With constant monitoring, it is possible to intervene in the equipment as soon as the variations are detected, in order to correct the faults before the equipment breaks down.
These types of maintenance require advanced technical knowledge of the team and are usually outsourced by specialist companies in each segment.