This method of protection has the benefits of Flameproof but does not require a specialised enclosure, generally a standard Industrial enclosure is suitable.
The only drawback of Pressurisation is that it requires a supply of protective gas, usually air, to purge the enclosure and keep it pressurised. The supply of purging and pressurising air is managed by a special control unit. Usually this is easier to purchase as a component ATEX/EX certified item.
There is a choice of several units on the market but for special applications, Atexxo Manufacturing prefers to design a custom model.
One advantage of purging and pressurising is that this protection concept also accommodates possible internal releases of flammable gas, vapour or liquid. This is relevant for analysers or other equipment that have a flammable liquid or gases passing through it.
Important Design Parameters
- Strength of the enclosure. The enclosure must be able to withstand 1.5 times the pressure of the gas inside it.
- The enclosure must be purged before the electrical equipment is energized.
- Shut-down or alarm in the event of the flow of the protective gas or the overpressure failing.
Electrical equipment whose normal operation involves sparks, arcing, or hot components and complex industrial standard equipment (controllers) whose protection type enables them to be operated in hazardous areas. Large machines, slip ring or collector motors, switchgear and control gear cabinets, and analysis devices.