Gas Detection Systems
The development of an explosive environment results mostly from the mixing of some explosive mist or gaseous substance with ambient air. Gases with toxic effects are also harmful to the environment and human life. Explosion and intoxication can be avoided with the installation of gas detection and signal systems.
The properly built out gas detection system issues a pre-signal at 20% of the lower explosion limit and an emergency signal at 40% of this limit. In the case of toxic gases, signalling of the approaching of the health limit or maximum concentration at work is the objective.
Gas detection systems are necessary in several situations. Some examples:
+ Technological gas detectors
+ Boiler house detection systems
+ Garages, parking houses
+ Dwelling space detection systems
+ Swimming pool halls
+ Food plants
+ Sewage processes
Based on the above, it is clear that the planning of a proper gas detection system is a fundamental element for explosion prevention. Therefore within our main line, our Company plans toxic flammable or explosive gas, steam detection and signalling systems for our users:
+ Selection of detectors
+ Installation plan
+ Working out and specification of the relating control functions
A gas detection system has two basic components: the detector(s) and the detection centre. During the selection of the detectors, the medium to be detected and the circumstances of installation must be taken into consideration. A major aspect is whether the system is installed within (design certified in accordance with ATEX directive) or outside the explosive zone. In addition to ATEX certification, MKEH-MFI, KERMI and CE certifications may be also necessary. The detectors may be connected to the centre in several procedures: 4-20 mA output, GAS ExPERT-64 bus system etc.
During the operation of the gas detection system, periodic inspection, control with instruments and adjustment are necessary in accordance with the requirements of the manufacturer and the standards. The required frequency may be 3 months.
Several circumstances and aspects must be taken into consideration during the planning, installation and operation of a gas detection system. The aspects and requirements are summarised in standards and regulations finalised during the time: MSZ EN 60079-29-1:2008 Explosive atmospheres.
Part 29-1:Gas detectors. Requirements of operation of the detectors of gas burners (IEC 60079-29-1:2007) and MSZ EN 60079-29-2:2008 Explosive atmospheres.
Part 29-2:Gas detectors. Selection, installation, use and maintenance of detectors for flammable gases and oxygen (IEC 60079-29-2:2007)