Electrical equipment in hazardous areas the participation of operations, maintenance, safety, electrical and instrumentation professionals, the use of process diagrams and material flows, MSDS and any pertinent documents, information and knowledge to determine the hazards and their extent and the countermeasures to be employed. Area classification documentations are reviewed and updated to reflect process changes. Soon after the introduction of electric power into coal mines, it was discovered that lethal explosions could be initiated by electrical equipment such as lighting, signals, or motors. The hazard of fire damp or methane accumulation in mines was well known by the time electricity was introduced, along with the
Damp proofing necessarily absolute; it is usually defined by a specific test method, limits, and engineering tolerances. Damp proofing is accomplished several ways including: Materials widely used for damp proofing include: A DPC is a durable, impermeable material such as slate, felt paper, metal, plastic or special engineered bricks bedded into the mortar between two courses of bricks or blocks. It can often be seen as a thin line in the mortar near ground level. To create a continuous barrier, pieces of DPC or DPM may be sealed together. In addition, the DPC may be sealed to the DPM around the outside