Abstract
Hazardous areas are commonly found in large facilities such as chemical processing plants, oil production platforms, oil depots, refineries, storage tanks, ships, grain silos, warehouses and other similar areas where there is a risk of explosion or fire due to explosive mixtures of vapors or dust. While most of the technicians working in such facilities or helping to design these installations are quite aware of the hazardous areas and the risks involved, the report of a recent study conducted by the UK Health and Safety Executive is surprising and alarming. It points to the fact that many of the so-called hazardous area installations do not meet the standards and some are completely unsafe. It noted that of the twelve major sites surveyed, only one passed inspection. This means that eleven of the twelve sites (up to 92%) had potentially hazardous hazardous area electrical and instrumentation installed. Fifty percent of these sites surveyed were in such poor condition that formal enforcement action by authorities was necessary. The high incidence of poor hazardous area installations is also believed to be behind many of the actual hazardous events reported.
This white paper attempts to help engineers and managers, not only in the UK but elsewhere, to gain a clear understanding of the subject and address the key issues involved.
The goal should be to make 100% of installations around the world safer.
Introduction
Hazardous areas in a typical installation fall into two areas. One is the likelihood of a flammable or explosive mixture being present in the area, and the other is the type of material present. Therefore, the classification requires the designation of the area (called area classification) as well as the material (material classification). The third parameter, temperature, is also important and is also classified by temperature. The device then comes with a marker showing the area, material and temperature classification where it can be safely installed, i.e. without risk of explosion.
So far so good, so what is the problem?
Read on to gain insight.
Area classification - what is the status of the hazardous area chemical plants?
Of the 12 sites mentioned above, many could not show any supporting documentation that they had classified (or zoned) their hazardous areas. The fact that they could not even mention the criteria for conducting zoning is alarming, to say the least, and could have potentially dangerous consequences. This demonstrates a lack of awareness of the basic concept of hazardous areas, which can only be corrected through proper training of the personnel involved.
Why poor area classification increases costs and reduces safety and how it affects you.
How to classify hazardous areas in a facility is one of the most important but least understood and ignored issues today. Why? Because in the long run, the way hazardous areas are classified can significantly impact the cost of operating a facility.
Globally, there are two main standards in area classification. One is the IEC (International Electrotechnical Commission) system, which is followed primarily in Europe, Asia, Australia and many other regions. The second system is the NEC (National Electrical Code), which is popular in North America and parts of the Middle East.The IEC system has three zones (Zone 0, Zone 1 and Zone 2) based on a reduced probability of the presence of an explosive vapor or gas mixture, and the NEC system has two (Zone 1 and Zone 2), again based on a reduced probability of the presence of a hazardous gas or vapor mixture.
If your facility is designed by engineers who incorrectly "over-classify" hazardous areas, then you will unnecessarily incur additional costs without any benefit. What is overclassification? Simply put, it is declaring an area to be hazardous when it is not. How does this increase costs? By forcing you to buy and maintain expensive explosion-proof equipment when ordinary weatherproof equipment would be just as good. Second, because the area is not dangerous anyway, you pay more for safety you don't need. It's the equivalent of wearing a helmet while eating lunch at home.
Declaring an area as Zone 1 when it should really be Zone 2 is also a case of overclassification. This then limits your ability to use cost-effective technologies, such as "non-flammable", that are only applicable to Zone 2 (but not allowed in Zone 1).
Worse, if your plant has large areas marked as "hazardous", you may have a very difficult time with the local authorities if you ask them for permission to expand, etc. These days they always suffer from NIMBY syndrome (not in my backyard). It would be very sad if the area should not be marked as dangerous, but some overzealous engineers have done that years ago.
What about underclassification? Underclassification is the declaration of an area as non-hazardous when it should actually be marked as hazardous. This may be due to ignorance or incompetence on the part of the design engineer, or the original design may have been modified by the owner/operator without consideration of reclassification. This is downright dangerous and far more serious. You should immediately and properly classify any areas that should be marked as hazardous and follow the safety standards for those areas. Install explosion-proof equipment for these areas where you will save money (labor and money) by giving hazardous areas the respect they deserve.
A large dust explosion occurred in a recent tragic incident in the United States. Misclassification of areas and the use of non-hazardous area electrical equipment in hazardous areas were cited as the cause of the disaster. Tragically, six people were killed in the incident.
Area Classification Problem ---- Mitigating the Root Cause
How can you fix this problem? By conducting an audit of your current facility, referring to currently available standards for marking hazardous areas, and training personnel in the basics of area classification. Logically, everyone who works in a hazardous area should know what a "hazardous area" is, and this knowledge can only be imparted through regular training. However, in today's business environment, regular classroom-based training is impractical and costly because there are no "standby employees" to cover those who must be sent out for training.
Therefore, e-learning programs remain the only cost-effective way to effectively train large numbers of operations and maintenance personnel on an ongoing basis.
Proper electrical explosion protection methods can improve safety, reduce hazardous events and lower costs.
If the IEC standards are followed, there are many different methods of electrical equipment explosion protection that are recognized. The most commonly used are explosion-proof/explosion-insulated, intrinsically safe, enhanced safety, non-flammable, pressurized/purged, encapsulated, and powder-filled. Not all methods can be applied to all situations, and not all methods have the same functionality. However, in situations where multiple explosion protection methods are allowed, choosing one type over the others can result in significant cost implications. For example, in a facility where one has Zone 0, Zone 1 and Zone 2 in various sections, then obviously in Zone 0 one can only use intrinsically safe, but in Zones 1 and 2 one can use intrinsically safe, as well as explosion-proof methods, and in Zone 2 one can use both methods as well as enhanced safety and non-flammability.
In this example, if only intrinsic safety is used everywhere, design and maintenance becomes simple, technicians only need to be trained in one type of installation, and the number of parts that must be stored in inventory for maintenance is minimal. This immediately means that while the initial project cost may be higher, the total cost of ownership is significantly lower. This one design basis can significantly impact overall lifecycle costs. However, in this example, if the design engineers decide to use different protection methods for different areas, they run into the problem of having multiple instructions for different areas (thus confusing the maintenance technicians, who may then make some dangerous mistakes). In this case, having to maintain multiple parts in the store is another disadvantage.
Another example is a facility designed years ago to only use blowdown anywhere. This wasn't a problem in earlier years, but now as the cost of compressed air has risen, so has the cost of blowdown every year! This would not have happened if they had used something like "increased safety" for example.
Another example is that there are no electrical devices in Zone 0 and Zone 1, but only in Zone 2. One can then easily use enhanced safety or non-flammable protection methods, which are much cheaper than using explosion-proof or intrinsically safe.
Therefore, the type of electrical explosion-proof method to be used is an important factor in the life-cycle cost of a facility. The right choice can result in better safety at a lower cost.
Worse than that, however, is the use of unsuitable hazardous area electrical equipment in hazardous areas. This means that even though it may be suitable for some hazardous areas, it is not all. For example, what is suitable for use in Zones 1 Group C and D cannot be used in Zones 1 Group B areas.
However, this design deficiency did occur many times and led to accidents. In one case in the United States involving an explosion at a facility handling ethylene oxide (a Group B gas under the NEC), it was discovered that the electrical equipment installed in the area was not suitable for Group B (even though it was explosion-proof). This lack of awareness was cited as the cause of the unfortunate incident.
This indicates an urgent need to train engineering staff in protection techniques. Thus, training these technicians can save your company thousands of dollars worth of capital as well as lifecycle (maintenance) costs. Again, e-learning programs are a fast, reliable and cost-effective way to transfer this knowledge to engineering staff.
Maintenance status of hazardous area installations
According to the UK study mentioned above, many hazardous area installations are maintained by contract workers whose training and competence in doing such work is questionable. In most cases, the capacity is weak and only one site provides some sort of refresher training for its employees.
This may be due to a number of reasons, including cost pressures to reduce manpower, wholesale outsourcing of maintenance functions to "lowest cost" contractors who may not be adequately trained, or simply because of layoffs in the process industry engineering departments (original engineers with design ideas no longer remain and are replaced by new people who know nothing about installation). new people who know nothing about installation).
However, if carefully scheduled maintenance and inspections are performed with trained manpower, many problems can be found that can be nipped in the bud. These could be many things, such as missing bolts on an explosion-proof box or improper grounding of an obstruction. Or it could be the installation of an instrument in Zone 1 that is certified for use in Zone 2 only (because the technician replacing it can't understand what those funny symbols and labels mean!
If such operations are tolerated, explosions and undesirable events may result. The cost of such events far exceeds the cost of preventive measures.
The cost of training employees should no longer be a constraint, as effective e-learning programs are very cost effective both as basic training and as refresher courses. In fact, the cost of training in this manner would be insignificant compared to the cost of ignorance that could lead to a major disaster.
The root causes of poor regional classification, poor choice of conservation methods and poor maintenance and what we can do to mitigate it
How exactly do these over- or under-classification problems occur? Why is it not done correctly when one conservation technique is chosen over another, or done without adequate consideration of life-cycle costs? Why do maintenance issues arise and sites that were designed and installed with the proper equipment to begin with become potentially unsafe installations?
This is because there seems to be a general lack of awareness of explosion protection methods and standards among many in design, engineering and industry today.
This was not seen before when industries had a large number of in-house trained engineers and technicians who were experienced and in turn had seniors and mentors (with lots of time) to train and maintain the "knowledge base" of the organization. This knowledge base has shrunk considerably today due to cost cutting, layoffs and reorganization in most in-house engineering departments.
As a result, many companies are under-resourced in engineering. So how do you solve this problem?
A quick and cost-effective solution is a rapid training and skills development program for hazardous area installations. The recommendations of the UK study mentioned above also show this. Young engineers and technicians often lack the guidance their predecessors received, which is risky for you, not only in terms of cost, but also in terms of safety.
Another approach is to hire an outside consultant to do this for you. However, this is not only costly, but more importantly, it does not add to the organization's knowledge base in any way that training employees certainly does. However, for effective training, the e-learning course you choose should be comprehensive (covering all aspects of the hazard area), easy to learn through animations and simulations, and test learners through assessments to determine how much material has been absorbed.
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