Explosion Proof

Explosion-proof (XP) is the more commonly used method for detector/sensor assemblies for fixed gas detection systems. It’s designed for permanent installations that require higher voltage/power. The term explosion proof describes electrical and non-electrical fixtures that can prevent explosions from occurring, and withstand explosions when they occur. An electrical product that is marked explosion proof, has an apparatus enclosed in a case that is capable of withstanding an explosion of a specific gas or vapor that may occur within it.

An explosion-proof classification for a sensor/transmitter means that the housing has been engineered and constructed to contain a flash or explosion. These housings are usually made of cast aluminum or stainless steel. They have sufficient mass and strength to safely contain an explosion should flammable gases or vapours penetrate the housing and the internal electronics or wiring cause an ignition.

The design must prevent any surface temperatures that could exceed the ignition temperature of a gas or vapour. If the sensing element is a high-temperature device (e.g. Catalytic bead or “pellistor”), it may be protected by a flame arrestor to prevent the propagation of high-temperature gases to the ambient atmosphere.