ATEX Explosion Protection & Ignition Properties of Hydrogen Gas

Hydrogen technologies are undergoing a significant period of growth as their widespread introduction is planned in the energy generation and production industries. Those of you with the knowledge of the properties and flammability of hydrogen will recognise that hazards due to explosive atmospheres must be assessed more and more frequently as the element is utilised, and, if necessary, appropriate protective measures must be taken. Learn more about dilution and ventilation of hydrogen gas here. 

The avoidance of ignition sources is one of the three basic measures for explosion protection.

To recap, the three basic methods of protection are:

• containment

Explosion containment allows the explosion to occur but confines it to a well-defined area, therefore avoiding the propagation to the surrounding atmosphere. Examples include explosion proof enclosures and motors that contain the explosion in their housing.  

• segregation

Segregation attempts to physically separate or isolate the electrical parts or hot surfaces from the explosive mixture, such as pressurisation or encapsulation.  

• and prevention

Prevention therefore limits the energy, both electrical and thermal, to safe levels under both normal, and fault conditions. The prevention of an explosion through limiting ignition sources is implemented primarily through the use of special, intrinsically safe, explosion-protected equipment. The design of which reduces the potential for the component to contribute as a source of ignition.

Non-electrical equipment such as ATEX industrial fans are important components that must be selected correctly according to accurate hazardous area classifications. Mechanically generated sparks or hot friction surfaces resulting from mechanical impacts caused by the rotating and stationary parts meeting for prolonged time periods, are considered in the prevention concept. This aspect is so important that it is stated in UK and EU ATEX legislation. Directives require the safe and effective construction of components in permissible material pairings to reduce this ignition source before they are placed on the market for use in hazardous environments. Learn more about reducing sparks and friction explosions with permissible pairings here.