lZero fault management of equipment is a management tool to maintain zero faults in equipment through maintenance, operations, and special training of equipment. In these processes, managers are constantly striving to minimize equipment damage, avoid equipment malfunctions during operation, and maximize economic benefits.
Primarily over time some parts of the equipment lose their original accuracy or performance, so that the equipment cannot function normally.
Technical performance decreases, resulting in equipment interrupting production or reducing efficiency and affecting production.
In most cases, over time during equipment use, due to friction, external forces, stress and chemical reactions, parts will always gradually wear and rust, fracture, and cause downtime due to failure.
It is essential to strengthen maintenance and repair of equipment, which can prevent financial losses due to business failures and shutdowns.
Generally, the operator or manager is unable to determine when the equipment is in normal condition, and when it should be considered abnormal and appropriate action should be taken.
So, for that, the business should set a special standard, which can indicate at what condition the equipment should be taken for maintenance.
For equipment maintenance purposes, it is very important to understand the failure rate of the equipment, and the circumstances under which the equipment fails.
First, we will focus on the equipment failure rate.
Equipment failure:
It is natural that over time the equipment temporarily loses its specified function during its life cycle, due to wear and tear or operational use. So, it is essential to know the exact causes of the failure of such equipment.
Unexpected failure:
The sudden failure of any equipment during its operational use can be a startling event. The timing of such events is not predetermined, so it is also difficult to predict, and the device function is lost during the process.
Failure due to depreciation:
The main reason for this type of failure is equipment usage time. Over time the equipment gradually deteriorates. which fails one day. So operational functions are disrupted. In this type of failure, managers may be aware of it.
Equipment failure rate:
Equipment failure rate is defined as the rate at which failures occur per unit of time.
Failure curve:
It is often observed that the failure rate of serviceable equipment over time, when displayed in a visual representation, is shaped like a curve, called a “bathtub curve”.
Equipment failure can be characterized by three different periods, depending on the equipment’s design and usage.
Initial failure period:
Although the rate of this type of failure is low, there are chances of failure due to some reasons, such as material defects, poor design and manufacturing quality, assembly errors, unskillful manipulation and other reasons.
Occasional failure periods:
This type of failure can be avoided, the rate of which is actually low and stable. which are caused by poor maintenance or operational errors.
Failure period due to Depreciation:
This can be considered a critical failure period, as the failure rate increases rapidly during this time. Which is actually due to the end of effective life of equipment.
Concept of zero equipment failure
In simple terms, zero equipment failure is using proper maintenance practices before equipment failure occurs. Specializing in repairing equipment, eliminating hidden hazards, equipment defects, and keeping equipment in good working order.
See the following points for an understanding of the concept of zero failure:
- Zero failure does not mean that the equipment will not fail, but it is necessary to eliminate the occurrence of defects and maintain a stable production sequence.
- The zero failure is a systematic concept, achieving zero failure for a device is not difficult. But how to reduce the impact of its shutdown and maintenance on the production to the lowest level is a complex process. The overall condition of the production equipment and the wider economic benefits of the production system should be widely considered.
- A key part of the zero-failure concept is to eliminate unplanned downtime and emergency maintenance. Sometimes caused by unplanned downtime and emergency repairs are enormous, and sometimes the consequences are severe.
What are the signs that indicate possible equipment failure?
If the equipment fails during the production processes, it causes more losses to the business. Therefore, if signs of failure are recognized before the equipment fails completely or stops operations, it is possible to repair it in a short period of time, so that:
- Economic losses can be prevented,
- Production processes and manpower time can be saved,
- Product quality can be maintained.
Signs of possible equipment failure are as follows:
Unusual work
Refers to the sudden abnormal behaviour of an equipment operating condition, which is the most common symptom of failure.
As entered:
- The device is difficult to start,
- slow to start, or is unable to start.
- Sudden automatic shutdown of equipment.
- Equipment running with insufficient power, low speed and reduced production efficiency.
- Sudden emergency brake failure, failure, etc. during the operation of the equipment.
The signs of this failure are obvious, so it is easy to spot.
Overheating and high temperature
One reason is that there is a problem with the cooling system, which is a lack of coolant, or the cooling pump is not working.
If gears, bearings and other parts overheat, it is most likely due to lack of lubricating oil.
Oil and water temperature too high or too low.
Overheating of devices can sometimes be directly reflected by the dashboard and warning lights, but sometimes it needs to be checked by a temperature spot check.
Excessive consumption of oil and gas
Excessive consumption of lubricating oil and cooling water indicates that the technical condition of some parts of the equipment has deteriorated, and there is a possibility of failure.
Compressed gas pressure is abnormal, etc.
Lubricating oil is unusual
The ubricating oils deteriorate faster than normal, which can be related to excessive temperatures.
Lubricating oil contains a lot of metal particles, which is usually related to the amount of friction of bearings and other friction, and wear parts such as bearings may need to be replaced.
Electrical effect
Change in resistance, conductivity, dielectric strength, and potential.
Second, signs of equipment failure in terms of appearance:
- Abnormal noise and vibration. An abnormal sound that occurs during equipment operation is an “alarm” of equipment failure.Intense vibration during equipment operation.
- Running and dripping. Leakage of equipment such as lubricating oil, gear oil, power steering fluid, brake fluid etc. Leakage occurs in compressed air, etc., and sometimes the sound of air leakage can be clearly heard. Leakage of circulating cooling water, etc.
- Has a special smell. When the motor overheats and the lubricating oil cylinder burns, it will emit a peculiar smell. Insulation materials such as circuit short circuit and iron wire emit a burning smell when ignited. Rubber and other materials emit a burning smell.
The various fault precursors mentioned above are fault information provided to operators and maintenance personnel so that they can detect accidents early and prevent problems before they occur.
Main causes of equipment failure
Equipment failure can be divided into four categories according to technical causes: abrasive failure, corrosion failure, fracture failure, and aging failure.
Abrasive failure
Exceeding the limit value at a certain moment due to the wear of the moving parts has a certain probability of failure.
The so-called wear refers to the phenomenon that the size, shape and surface quality change under the action of friction in the process of mechanical contact between two surfaces for mutual movement.
According to its formation method, it is divided into four types: contact wear, surface fatigue wear, corrosion wear and micro-vibration wear.
Corrosion failure
According to different corrosion mechanisms, it can be divided into three categories: chemical corrosion, electrochemical corrosion, and physical corrosion.
- Chemical Corrosion: Corrosion due to direct chemical reactions between metals and the surrounding media. No current is produced during the reaction.
- Electrochemical Corrosion: Corrosion due to electrochemical reactions between metals and dielectric solutions. An electric current is produced during the reaction.
- Physical corrosion: The metal is in contact with molten salt, molten soda, liquid metal, so that one area of the metal continues to melt, and another area continues to form a material transfer phenomenon, that is, physical corrosion.
In actual production, it is often classified into different forms of metal corrosion. There are 8 general forms of corrosion, such as uniform corrosion, galvanic corrosion, crevice corrosion, pitting corrosion, intergranular corrosion, selective corrosion, abrasive corrosion, and stress corrosion.
Fracture failure
It can be divided into brittle fracture, fatigue fracture, stress corrosion fracture, plastic fracture, etc.
- Brittleness Fracture: May be caused by uneven material properties; or due to improper processing technology (such as improper treatment in forging, casting, welding, grinding, heat treatment and other processes, it is easy to produce brittle fracture); It can also be caused by a harsh environment; If the temperature is too low, the mechanical properties of the material are reduced, mainly referring to the reduction of the impact toughness, so the cryogenic container (below -20 ℃) must choose a material with an impact value greater than a certain value. Another example is radiation which can cause the material to deteriorate, resulting in brittle fracture.
- Fatigue fracture: fracture due to thermal fatigue (such as high temperature fatigue, etc.), mechanical fatigue (divided into bending fatigue, torsional fatigue, contact fatigue, joint load fatigue, etc.) and fatigue in a complex environment.
- Stress corrosion fracture: A type of cracking in thermal, welding, residual, or other external stress equipment if there is a corrosive medium in contact with the metal material at the same time, which will cause cracks in the material to develop at a significant rate. For example, cracking of stainless steel in a chloride medium and cracking of brass in an ammonia-containing medium is a stress corrosion fracture. Another example is damage caused by so-called hydrogen embitterment and alkali embitterment, which are also stress corrosion fractures.
- Plastic Fracture: Plastic fracture occurs due to overload fracture and impact fracture.
Aging failure
The above extensive factors act on the equipment and cause failure due to its aging performance.
Factors that affect the Failure of Equipment
As we know, equipment failure can have many causes. There are many methods of classification, and in order to implement these methods one must focus on the influencing factors. Various aspects of equipment failure are given below:
Life cycle:
This is an important factor, which can cause failures due to equipment aging over time. May also include items such as outdated technology or / and equipment.
When we talk about the life cycle of equipment, it can be in two categories.
One is congenital equipment failure – which can occur due to inherent defects in the equipment, particularly due to improper design and manufacture of the equipment.
Another is failure due to serviceability – this may include failure arising from equipment installation and maintenance, operation, natural deterioration of equipment and other factors.
Human Factors:
Strictly speaking, the inherent failure of equipment is a human factor failure, which is not only related to the level and responsibility of the designer and manufacturer but is also subject to the gradual obstacles of scientific and technological development.
After the equipment is operational, careful operation and daily management become the most important human factors. “Disasters are hidden in the unconscious, and so are those that occur in the neglect of the people.”
Improper installation:
Especially in any manufacturing sector, equipment may be more prone to failure due to improper installation or improper configuration.
Improper wiring, alignment, or adherence to manufacturer’s instructions when installing the equipment may result in failure.
Environmental Factors:
Naturally, it is natural for any tool or material to be affected by the environment. Especially common are extreme temperatures, humidity, dust, or other environmental factors.
Corrosion of iron tools:
Here we are distinguishing corrosion, because every tool in any manufacturing or assembly unit is made of iron, which corrosion quickly deteriorates. Where salt water is used or exposure to environments such as humidity increases failure.
Depreciation:
Have you ever worked in, or visited, a manufacturing field and seen rotating parts of a machine – such as bearings, gears, or other mechanical parts – wear out from regular use and fail slowly. .
Lack of maintenance:
In any manufacturing sector, machinery and its maintenance are very important. If equipment is not properly maintained, it can develop problems, leading to failure over time. In particular, insufficient level of lubrication, lack of timely cleaning and oiling, and timely repair or replacement of worn parts can lead to malfunction.
Power Fluctuation:
Power fluctuations in industrial units can be hazardous to machinery, equipment and devices. This can include things like voltage spikes, brownouts, or other power issues that can damage sensitive components.
Improper Use:
Any tool has its own characteristics, limitations, design and methods of use. But it often happens that a machine is used for a job for which it was not made. It also happens that a machine is operated at a speed higher than its rated speed which is higher than the recommended speed, in such cases the machine may be damaged.
That is also important to note that different industries have different types of machinery, so different factors are involved. It is also important to understand which reasons will apply to what conditions and to whom.
Equipment failure modes
Equipment failure modes are mainly composed of bathtub curves. .
For early failures, an in-depth study of various fault symptoms, investigation and analysis of equipment accident causes, and corresponding countermeasures should be specified.
During the period of equipment depreciation, unexpected sudden failures should be avoided, TPM (Total Production and Maintenance) should be strengthened, and various monitoring technical means should be widely used to understand and master equipment management trends and manage equipment deterioration trends.
How to achieve Zero equipment failure
Equipment zero fault management is a complex system engineering, and its management process is extensive.
It requires full participation – from the inspector to the operator and maintenance worker, and the entire process – all stages of equipment operation.
The process of achieving zero fault management of equipment is also a process of improving the building of corporate culture.
The way to achieve zero equipment failure is discussed from the following aspects.
How to achieve zero equipment failure?
Implement TPM and RCM
In fact, the aforementioned basic activities and standardization work to reduce defects are the essence of TPM, which is characterized by full participation.
RCM takes preventive maintenance as a starting point and ensures planned maintenance according to the results of equipment condition monitoring. So that maximum utilization of equipment and lowest maintenance cost is achieved.
Strengthen equipment condition monitoring and fault diagnosis
This is an effective means of avoiding equipment failure and unexpected accidents.
At this stage, any production area should focus on equipment condition monitoring and fault diagnosis:
Spot check of equipment section
Continue to improve the two-tier monitoring network of section spot checks. Implement quantitative spot checks and truly promote condition monitoring and fault diagnosis technology to department teams and front-line personnel. Which can be the key to achieving zero equipment failure.
The form should document standardized equipment condition monitoring and easy fault diagnosis operations.
Strengthen networked online monitoring and diagnostics of key equipment.
Vigorously promote the use of networked online monitoring technology, detect hidden equipment hazards early and avoid the occurrence of fatal equipment accidents.
Focus on diagnostic technician training.
Create a good work environment, and take care of employees in all aspects
From a monthly equipment failure perspective, equipment failures due to “improper operation” and “poor maintenance” account for 1/3 or more of monthly equipment failures.
Why?
Apart from the fact that the above basic activities and standardization operations are not taken seriously, it is also closely related to the enthusiasm and initiative of most of the employees.
As the management department at all levels of the company, they should study this issue seriously and start from all aspects of their work and life.
To carry out zero-fault management, it is necessary to establish a new concept and way of thinking; To carry out zero-fault management, there is no unified model, and in practice it must be constantly discussed and summarized; Zero-fault management will have a profound and long-term impact on all aspects of equipment infrastructure management.
Standardization
Defect reduction activity is an upward process, and to achieve ideal conditions. It is necessary to establish standardized operating documents. Which are the basis of the above activities and the soul of all management work.
The standardization process is a process from small to large, simple to complex. It is impossible to do in one step, and the annotated documents need to be revise and improve continuously.
Conclusion
The concept of zero equipment failure, causes of equipment failure and analysis of equipment maintenance methods of zero fault management have been discuss above.
By focusing on specific methods of zero-fault management.
To carry out zero-fault management, it is necessary to establish a new concept and way of thinking. To carry out zero-fault management, there is no unified model. In practice it must be constantly discuss and summarize. The Zero-fault management will have a profound and long-term impact on all aspects of equipment infrastructure management.