What is explosion protection?
Operating plants or areas where inflammable substances in sufficient quantity get in contact to oxygen (air) become a hazardous area. In this case, measures are necessary in order to exclude the danger of ignition by electric or mechanical operating equipment (devices, tools, machines or vehicles).
In order to exclude the danger of explosion by ignition sources, you have to use operating equipment with explosion protection, if required.
Types of Protection:
"Types of Protection" for operating equipment according to the the standardisation work are e.g. "Flame-proof Enclosure", "Increased Safety", "Powder Filling" or "Restricted Breathing Enclosure" which offer the same protection against the danger of ignition amongst themselves.
Classification of Areas:
Hazardous regions are classified in areas. Depending on the extent of explosive atmosphere, these are for gases, vapours, mists:
| zone 0 |
(category 1G *): |
continuously or long-term or frequently |
| zone 1 |
(category 2G *): |
occasionally |
| zone 2 |
(category 3G *): |
infrequently or short-period |
* = equipment category according to the new regulation 94/9/EC - "ATEX"
Explosion Groups:
Explosive gases and steams are classified in explosion groups:
| IIC |
e.g. hydrogen, acetylene, carbon bisulphide |
| IIB |
e.g. natural gas, ethylene |
| IIA |
all other gases |
Temperature Classes:
Depending on the ignition temperature, inflammable gases and vapours are classified in temperature classes. The maximum surface temperature of an electric operating material has always to be lower than the respective ignition temperature.
| T6 |
< |
85 °C |
| T5 |
< |
100 °C |
| T4 |
< |
135 °C |
| T3 |
< |
200 °C |
| T2 |
< |
300 °C |
| T1 |
< |
450 °C |
|
