“The X Factor”: what to look for when purchasing Ex equipment
Navigating the complexities of safety standards in hazardous environments can be challenging, especially when it comes to selecting the right equipment. If you are responsible for purchasing or selecting equipment for hazardous areas, you need to know how to read the symbols contained in certificates and rating plates.
When purchasing equipment and electrical accessories intended for use in hazardous areas, it is crucial to ensure they meet the basic requirements of health and safety regulations and directives, as well as the user’s specific expectations regarding functionality, purchase price, and delivery time. However, to make a fully justified purchase decision, additional factors such as the cost of installation, operation, maintenance, and service should be considered. Also, don’t forget the indirect costs resulting from equipment downtime due to installation, failure, or maintenance.
Certification and marking complexities
For explosive atmospheres, the purchasing decision is further complicated by European and international regulations on certification and marking of explosion-proof equipment. These regulations allow manufacturers to mark their products with the enigmatic “X” symbol (the last item in the type examination certificate number, commonly referred to as the ATEX certificate). This symbol indicates to buyers and users that the safe use of the device requires special conditions to be met.
Additional costs of Ex equipment: installation and maintenance
But what exactly does the “X” symbol mean? Generally, the “X” symbol can both expand and significantly limit the range of applications of a given device. The precise meaning is detailed in the ATEX certificate of the device in question and should also be included in the instruction manual. However, practice shows that some manufacturers neglect to include this information or have issues properly translating it into the language of the country where the device is sold.
Why is detailed information on special conditions for safe use so important from the buyer’s perspective? Because the provisions of this part of the ATEX certificate can lead to additional costs for installation, maintenance, or service.
Handling existing Ex equipment
A real problem arises when an explosion risk assessment for an already operating plant reveals that the notations behind the “X” symbol prevent its continued operation. A possible solution is developing a detailed risk assessment for the particular piece of equipment, demonstrating whether it can be safely operated under specific process conditions. However, it must be verified if the costs associated with performing such an assessment (including testing and expertise) exceed the cost of replacing the device, and if a positive outcome is likely.
Due to these complexities, it is extremely important that users of explosion-proof equipment fully understand the meaning and implications of the “X” symbol. It is equally crucial for engineers to recognize the subtle technical differences between equipment from different manufacturers, as similar solutions with the same ATEX classification may require vastly different investments due to the restrictions behind the “X” symbol.
Low risk of mechanical damage
The restriction to install a device only in areas with a low risk of mechanical damage excludes its use in many areas of production, transport, and loading, as demonstrated in the explosion risk assessment.
Impact resistance of less than 7N
A device’s housing must have an impact strength of less than 7N according to guidelines for explosion-proof devices. Purchasing a device with reduced strength can be likened to buying a sports car without airbags, which can only be driven at speeds below 40km/h.
Reduced operating temperature range
Narrowing the standard range of ambient temperature from -20°C to +40°C to a range from 0°C to +40°C means the device can practically only be used indoors.
Labor-intensive installation
An “X” device may require special installation and maintenance conditions. This can include labor-intensive procedures for mounting the device with expensive fasteners, on pain of invalidating the certificate.
Unmasking the costs: the hidden price tag of Ex equipment
In conclusion, selecting equipment designed for explosive atmospheres is akin to peeling an onion; each layer reveals new and often hidden costs. These costs, associated with installation, operation, and maintenance, must be carefully considered. It is equally crucial to understand the restrictions and special conditions for safe use that often hide behind the enigmatic “X” symbol. Just as with an onion, ignoring these layers can lead to tears later on.