From ISO 12944 requirements to advanced testing: Cortem solutions for corrosion protection in extreme atmospheres

With regard to explosion hazards due to the presence of combustible dusts, the correct matching between plant location and equipment follows the same logical approach used for potentially explosive gases. This symmetry is intentional, as it facilitates designers and installers in the selection and installation of the appropriate equipment. Let's see the choice of equipment based on EPL, dust group and maximum surface temperature.

Today, polyester-based powder coatings provide high corrosion resistance even in harsh and extreme ambient temperature conditions. Their application process—and, of course, their formulation—is of great importance

An increasingly frequent case for the construction of Zone 1 switchboards is the use of Ex eb enclosures for the integration of electromechanical components and/or electronic interfaces compliant with and with EPL Gb certification.

To save energy in lighting systems located in areas at risk of potentially explosive atmospheres, it is possible to decide to intervene by automatically switching off the devices after a certain number of hours or, where possible, by reducing the luminous flux at the outlet thanks to the use of floodlights, linear lighting fixtures and high bays with several types of dimming.

In intrinsically safe systems, associated equipment plays a key role in the safety of the system. Their positioning can be foreseen outside the hazardous area or, alternatively, in explosion-proof enclosures that can provide them with adequate protection for installation in Zone 1.

Cold flow in cables is the movement of the cable sheath/filler under compressive forces created by moving gaskets in the cable glands, where the compressive force applied by the gasket is greater than the resistance of the cable sheath/filler to deformation.

Metallic materials are not subject to the typical problems of plastic materials such as aging and resistance to UV rays, but rather can become ignition sources themselves. This is why the legislation pays particular attention to the parts that act as housing.

In this article, we will delve into the connection of 'Ex db' and 'Ex eb' electric motors with 'Ex eb' junction boxes to the power line using electrical connection accessories, i.e. adapters, sealing fittings, cable glands and flexible tubes. Being able to use an Ex-eb cable gland is not at all negligible from an economic point of view. The time saving during installation compared to installing a sealing fitting or an Ex-db cable gland is considerable.

In the design and use of electrical devices we must manage conductive parts with different electrical potential, with even very high voltage differences. The risk of formation of electric arcs in the air and creeping currents on the surface of the insulation material must be considered. To limit these phenomena, during the design phase we intervene on the distances between exposed conductive parts.

In a world where the installation speed, the overall site security and the installation and maintenance costs are increasingly important, the use of specific connectors as FlowEx series can find wide application.

Often the meaning of the supplementary letter is little known, misunderstood and misinterpreted. Not understanding the difference between component and equipment or thinking that a certificate with the final "X" is a sort of B-series certificate with strong limitations on the use of the equipment is completely anachronistic today.

The systems are mainly divided into systems with metal protective conduits and cable systems. The various devices require cable entries suitable for the type of protection used. The type of cable entry may appear to be a mere theoretical argument, but it has a decisive impact on the safety level of the system.

In sites where there is a risk of the formation of an explosive atmosphere, we often find the electrical conduit in a metal protective tube (also called conduit conduit). Although it has recently been joined by more versatile armored and non-armored cable systems, with cable gland entry, its use is recommended in plants where production or use and maintenance activities can present dangerous situations for the integrity of the cables.

Sealing fittings are often considered only as secondary or minor components, but the safety of an installation with metal electrical conduits and related explosion-proof enclosures depends on them. The main function of a conduit sealing fitting is to prevent the propagation of an explosion from the inside of the ‘Ex d’ flameproof enclosure to the outside.

Explosion-proof joints are one of the basic aspects of the protection offered by an equipment or an explosion-proof enclosure. For this reason, understanding their function is a prerequisite for the correct use and the proper maintenance of all electrical devices that adopt this type of protection.

A fundamental principle of the ATEX Directive 2014/34 / EU, shared with the other Union directives, is the limitation of legislative harmonization to essential health and safety requirements of public interest. Within this legislative harmonization, a role of primary importance is played by the harmonized technical legislation and the concept of the state of the art. The ATEX Directive refers to this concept as a requirement requested of manufacturers.

Each equipment that must be installed in an ATEX classified area must have a certain level of protection, indicated in the legislation with the acronym EPL (Equipment protection Level). The level of protection is obtained by applying technical regulations that define the protection methods. There are many ways of protection, some have a historical origin, others are more recent...

A correct earthing system must comply with all safety requirements and carry out the standard procedure.