1.       Disassembling the equipment without locating the fault

Some maintenance personnel do not know the structure and mechanism of engineering equipment and would not carefully analyze the cause of failure. They just blindly disassemble the equipment before locating the faulty part. As a result, they fail to fix the fault, and even worse, they create new problems due to poor maintenance skills. Therefore, maintenance personnel must use instruments, such as endoscope and vibrometer, to diagnose the equipment and determine the most likely faulty part based on the equipment’s structure and mechanism.

2.       Blindly replacing parts

Troubleshooting engineering machinery is challenging. Some maintenance personnel simply replace any part, big or small, that they think might be faulty. As a result, the failure persists, and unnecessary replacement of parts increases the costs of users.

3.       Using a new part without checking its quality, causing failure again

Some maintenance personnel replace the faulty part with a new one without performing any technical test, which is not acceptable. The quality of spare parts on the market varies greatly. Counterfeit and shoddy parts exist. Some parts have been stored for a long time and their performance may change. If used, these parts may cause equipment failure.

4.       Using the wrong type of replacement parts

Substitute parts and misuse of replacement parts are common in machinery maintenance. Substitute parts are acceptable in emergencies, but long-time use of such parts will compromise the equipment’s safety and technical performance. Therefore, original spare parts should be the first choice for repair.

5.       Using quick fixes

When troubleshooting engineering equipment, some maintenance personnel rely on quick fixes without addressing the root cause. This practice must be changed. Maintenance personnel must try to identify the root cause of failure, and fix the problem once and for all.

6.       Using gaskets in an incorrect way

A variety of gaskets are used between two mating surfaces to prevent leakage of oil, water, gas and electricity or simply fill the space between the mating surfaces. Commonly used gaskets include felt gaskets, metallic gaskets (copper and aluminum), copper-skin or steel-skin asbestos gaskets, insulation gaskets, spring gaskets and flat gaskets. Application of these gaskets is subject to different requirements. However, misuse of gaskets is common in machinery maintenance, resulting in frequent leakage between mating surfaces and self-loosening of bolts and nuts, ultimately compromising the normal use of machinery.

7.       Ignoring small part maintenance, leading to increased failure

Some maintenance personnel only maintain important parts such as the drive chain, oil pump, hydraulic oil pump, brake, and lubrication system, but ignore small parts such as the filter, spill valve, and all kinds of instruments. In their opinion, small parts do not affect the work of the machinery, even if they are damaged. However, if not properly maintained, these small parts will lead to early wear and tear, and reduce the service life of the machinery.

8.       Violating maintenance taboos, resulting in hidden failure

Some maintenance personnel often make habitual errors when disassembling or assembling a machine, affecting the quality of mechanical maintenance. For example, when they dismantle interference fits, such as bearings and pulleys, they usually use brute force instead of proper tools, which may easily lead to deformation or damage of the parts.

9.       Cleaning components incompletely, leading to early damage and corrosion

It is important to keep machinery components clear of oil, dirt and impurities so as to extend the machinery’s service life. Insufficient cleaning, wrong cleaning agents, and improper cleaning methods will result in early wear, tear and corrosion of components.