It is easily forgotten that an ignition source in an explosive atmosphere need not be electrical. A rotating shaft, an overheating bearing, belt friction or a spark from metal striking metal is quite enough. EN 13463-1 sets the requirements for that non-electrical equipment.
Potential ignition sources
- Hot surfaces — overheating bearings and braking mechanisms.
- Mechanical sparks — metal striking or rubbing on metal.
- Static electricity — belts, plastic parts, flowing powder.
- Adiabatic compression and shock waves.
- Chemical reactions and exothermic processes.
Types of protection
- c (constructional safety)
- Constructional safety — design that prevents friction and overheating
- b (control of ignition source)
- Control of ignition source — sensors that shut the equipment down
- k (liquid immersion)
- Liquid immersion — the potential source is isolated in liquid
- d, p, fr
- Flameproof, pressurised and flow-restricting enclosures
Note that the EN 13463 series has been progressively replaced by EN ISO 80079-36 and -37, though the older marking is still on a great deal of equipment in service.
Superseded by EN ISO 80079-36.