Caution: Explosive! Drum handling in EX areas
Working with flammable substances brings with it a risk potential that should not be underestimated. When combined with the right mix of oxygen and an ignition source, an explosive atmosphere is formed and the consequences can be severe.
Where flammable liquids are filled, extreme caution is required. If a container is opened for the purpose of liquid extraction, the formation of an explosive atmosphere must be expected. It is therefore essential to take appropriate measures to prevent the risk of an explosion.
We provide you with some essential information and our recommended product solutions below.
The trigger of an explosion is the interaction of oxygen, a combustible substance and an ignition source. Also important is the mixing ratio between the oxygen and the combustible material. The prerequisite for an explosion is a suitable concentration of the substance. Depending on the substance, this must be between the upper and lower explosive limits. If the lower explosion limit is not reached, there can be no explosive atmosphere. If the environment is saturated by the combustible material, ie the upper explosion limit is reached and the oxygen content is too low, an explosion is also excluded.
In order to prevent an explosion, you must also consider the mixing ratio of oxygen to combustible substance.
DSEAR (Dangerous Substances and Explosive Atmospheres Regulations 2002) requires employers to eliminate or control the risks from dangerous substances and in addition to the general requirements, the Regulations require employers must classify areas where hazardous explosive atmospheres may occur into zones. The classification given to a particular zone, and its size and location, depends on the likelihood of an explosive atmosphere occurring and its persistence if it does.
An area in which hazardous explosive atmospheres are present continuously, over long periods or frequently (i.e., predominantly in time).
e.g. the inside of containers
An area in which a dangerous explosive atmosphere can occasionally form during normal operation.
e.g. the closer environment of zone 0 or the environment of the filling station
An area in which during normal operation a dangerous explosive atmosphere normally does not occur or only for a short time.
e.g. Areas surrounding zones 0 or 1
Depending on the zone, various safety precautions must be taken to prevent explosion. If there is any doubt about the zoning, the extent of the protective measures must be based on the highest possible probability of the occurrence of hazardous explosive atmospheres.
Explosion protection measures can be divided into three areas (the order of the measures is synonymous with their prioritization):
1. Avoidance or limitation of the formation of explosive atmospheres
2. Avoidance of effective ignition sources
3. Limitation of the effect of a possible explosion to an acceptable level
However, avoiding the formation of an explosive atmosphere is in many cases not feasible. For example, this goal can be achieved by replacing flammable substances with those that can not form explosive mixtures. A substitution of supplies is, however, possible in very few cases. Technical ventilation can help to reduce flammable substances within the ventilation area (effectiveness in these cases should be assessed and monitored in terms of strength, quality and availability). However, if it is not possible to completely eliminate dangerous explosive atmospheres, further safety measures are nevertheless necessary. The avoidance of ignition sources therefore applies in practice as a particularly practical solution.
With the use of EX-proof equipment you make an important contribution to the daily explosion protection in your company and to the safety of your employees. Ex-proof equipment placed on the EU market must comply with the requirements of the ATEX Directive. This applies equally to electrical and non-electrical devices. The manufacturer of products for use in potentially explosive atmospheres is required to develop these products in accordance with the requirements set out in the Directive and to specify in which zone they may be used.
Pumping and mixing
To convey or mix flammable liquids, electrical pumps and agitators must meet the requirements of the ATEX Directive. The motors are designed so that the devices can be safely operated. Non-electrical components are designed to also accommodate e.g. hot surfaces be avoided as ignition sources. To dissipate static electricity, our electric pumps for hazardous areas are already supplied including equipotential bonding cables. Our hand pumps for hazardous areas are DEKRA approved and can be grounded with separately available grounding cables or anti-static kits.
Lifting and transporting drums
It is not just the use of electrical equipment that can create ignition sources. When moving drums with mechanical tools, sparks can be mechanically generated by friction, meaning static charge must also be excluded as an ignition source. Products are available which are designed to be completely dissipative, so that they do not have to be earthed by a directly connected equipotential bonding system.
Using commercially available steel tools can cause sparks - for example, by hitting or dropping the tool on the ground. Non-sparking tools are made from special copper-based alloys and are softer than traditional tools, minimizing the risk of sparking. They are certified for use in areas where sparks pose a potential explosion hazard. Important to know: The use of non-sparking tools must not be the only protective measure in fire or explosion-prone areas. Please observe the regulations of your professional association.
When filling or conveying flammable substances, it must be taken into account that dangerous charges may be caused by the liquid flow alone. The risk of static charge increases with the flow or bulk rate of the medium. With the help of earthing cables users avoid the risk of explosion due to electrostatic charging.
Detect Dangerous Leaks Quickly
Leaking flammable liquids can quickly create an explosive environment. To avoid this dangerous situation we recommend using a SpillGuard® - the new hazardous substance leakage warning system created by DENIOS. Place this innovative device in your spill pallets and be instantly warned of any dangerous leaks.
SpillGuard® releases a continuous alarm and LED light system for up to 24-hours, alerting you to any nearby dangers.
Land markings play an important role in safety and day-to-day operations. Material zones, loading areas or safety distances to machines and systems are usually indicated by signs and instructions, in addition to floor markings. In addition to individual requirements and application forms, there are also legal regulations that regulate marking on the floor.
For marking of potentially explosive areas we also offer you a wide range of floor markings. At a glance, employees are shown which work areas they need to be particularly cautious about.
The technical information on this page has been prepared carefully and to the best of our knowledge and belief. Nevertheless, DENIOS can not assume any warranty or liability whatsoever, whether contractual, tortious or in any other way, for its timeliness, completeness and accuracy neither vis-à-vis the recipient of this magazine nor third parties. The use of information and content for your own or other purposes is at your own risk. In any case, observe the local and current legislation.
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