IEC 60079-16:1990 pdf download.Electrical apparatus for explosive gas atmospheres
1. Scope
1.1 This report provides the general principles of protection, by artificial ventilation, of analyzer(s) houses against the explosion hazards caused by internal release of flammable substances and, if applicable, against the hazards caused by an external explosive gas atmosphere. It also gives the conditions in which electrical apparatus liable to cause ignition may be used in these analyzer(s) houses. These analyzer(s) houses may be situated in a hazardous area or in a non-hazardous area.
1 .2 This report contains recommendations for the construction and operation of analyzer(s) houses, for their associated installations, such as air ducts, and for the auxiliary devices necessary for providing and maintaining the conditions for ventilation and, when required, pressure.
This report also specifies the verification and testing necessary to prove that the installation conforms to the above recommendations, and the markings to be placed on such rooms or buildings.
Notes 1.- In certain circumstances, the recommendations may be used for other buildings containing similar sources of release.
2.- This report does not deal with dangers associated with the toxicity of gases and vapours which may be dealt with by similar techniques. It does not deal with requirements not related to explosion safety.
2. Definitions
For the purpose of this report the following definitions apply:
2.1 Analyzer(s) house
A specific closed room or building containing one or more analyzers for samples of flammable fluids which are or may be connected to a process installation together with electrical equipment and auxiliary devices.
Note.- Analytical laboratories are not covered.
2.2 Artificial ventilation
A method of mechanical movement of air to reduce and maintain at a safe level the concentration of flammable gases or vapours in the analyzer(s) house. Such ventilation may also be used to maintain the pressure inside the analyzer(s) house above or below
the external ambient pressure.
3.2 Requirements for the analyzer(s) house
The analyzer(s) house should preferably be a separate building.However, it may sometimes be necessary to incorporate the analyzer(s) house in an existing building. In such cases the analyzer(s) house should be completely isolated from other parts of the building except as permitted in Sub-clause 5.3. However, air-locks with appropriate safety provisions may be permitted between the analyzer(s) house and the remainder of the building if the requirements of Sub-clause 5.3 are met. For examples of arrangements see Appendix A.
3.2.1 All analyzer(s) houses in which flammable substances are handled will affect the surrounding atmosphere. These effects should be taken into account when the hazardous areas for the su rroundings are defined, especially when the analyzer(s) house is to be located in an otherwise non- haza rdous area. In particular, when gas samples have to be released to the atmosphere, the effects of these releases should be ta ken into account. IEC 60079-16 pdf download.