What is an explosive atmosphere?
An explosive atmosphere location is defined as a place where concentrations of flammable gases, vapors, or dusts occur. If there is enough of the substance, mixed with air, all that is needed is a source of ignition to cause an explosion.
Explosions could lead to loss of life and serious injuries as well as significant damage and expense. Preventing the concentrations of dangerous substances, which create an explosive atmosphere, and preventing the ignition source are the two most commonly used ways of reducing the risk.
All electrical equipment that must be installed in hazardous locations are specifically designed and tested to ensure it does not initiate an explosion, due to arcing contacts or high surface temperatures of equipment.
A stabilised system is where the power loading of the trace heating tape is such that under conditions of no temperature control i.e. thermostat failure, the sheath temperature of the heating tape cannot exceed the ‘T’ classification.
Ideally all heat trace systems should be designed to be stabilised systems.
NOTE: Non-stabilised designs may lead to operational problems as the over-ride thermostat may prevent the electric trace heating system delivering the required heat output (kWhr) under low ambient temperature conditions. It is therefore essential that the thermal design characteristics of the system are carefully evaluated.
- Zone 0 – an area or enclosed space within any flammable or explosive substance, whether as, vapour, or volatile liquid, is continuously present in concentrations within the lower and upper limit flammability.
- Zone 1 – an area in which any flammable or explosive substance, whether gas, vapour or volatile liquid is processed, handled, or stored, and is likely to occur in sufficient quantities to produce a hazard.
- Zone 2 – an area in which any flammable or explosive substance, whether gas, vapour or volatile liquid although processed or stored, is so well under conditions of control that the production or release of an explosive or ignitable concentrate in sufficient quantity to constitute a hazard is only likely under abnormal conditions.
ESH Hazardous Area Trace Heating
As an ATEX Certified company, ESH Trace Heating Ltd hold approvals for the manufacture and installation of explosive atmosphere trace heating solutions.
If you have a specific design requirement or need advice, please contact us