TP056 - Pravilnik o protieksplozijski zaščiti

IEC/TS 60079-32-1:2013(E) gives guidance about the equipment, product and process properties necessary to avoid ignition and electrostatic shock hazards arising from static electricity as well as the operational requirements needed to ensure safe use of the equipment, product or process. It can be used in a risk assessment of electrostatic hazards or for the preparation of product family or dedicated product standards for electrical or non-electrical machines or equipment. The purpose of this document is to provide standard recommendations for the control of static electricity, such as earthing of conductors, reduction of charging and restriction of chargeable areas of insulators. In some cases static electricity plays an integral part of a process, e.g. electrostatic coating, but often it is an unwelcome side effect and it is with the latter that this guidance is concerned. If the standard recommendations given in this document are fulfilled it can be expected that the risk of hazardous electrostatic discharges in an explosive atmosphere is at an acceptably low level. Keywords: risk assessment of electrostatic hazards, static electricity

This part of IEC 60079 is concerned with the classification of areas where flammable gas or
vapour hazards may arise and may then be used as a basis to support the proper selection
and installation of equipment for use in hazardous areas.
It is intended to be applied where there may be an ignition hazard due to the presence of
flammable gas or vapour, mixed with air, but it does not apply to:
a) mines susceptible to firedamp;
b) the processing and manufacture of explosives;
c) catastrophic failures or rare malfunctions which are beyond the concept of abnormality
dealt with in this standard (see 3.7.3 and 3.7.4);
d) rooms used for medical purposes;
e) commercial and industrial applications where only low pressure fuel gas is used for
appliances e.g. for cooking, water heating and similar uses, where the installation is
compliant with relevant gas codes;
f) domestic premises;
g) where a hazard may arise due to the presence of combustible dusts or combustible flyings
but the principles may be used in assessment of a hybrid mixture (refer also
IEC 60079-10-2).
NOTE Additional guidance on hybrid mixtures is provided in Annex I.
Flammable mists may form or be present at the same time as flammable vapour. In such case
the strict application of the details in this standard may not be appropriate. Flammable mists
may also form when liquids not considered to be a hazard due to the high flash point are
released under pressure. In these cases the classifications and details given in this standard
do not apply. Information on flammable mists is provided in Annex G.
For the purpose of this standard, an area is a three-dimensional region or space.
Atmospheric conditions include variations above and below reference levels of 101,3 kPa
(1 013 mbar) and 20 °C (293 K), provided that the variations have a negligible effect on the
explosion properties of the flammable substances.
In any process plant, irrespective of size, there may be numerous sources of ignition apart
from those associated with equipment. Appropriate precautions will be necessary to ensure
safety in this context. This standard is applicable with judgement for other ignition sources.
This standard does not take into account the consequences of ignition of an explosive
atmosphere.

This part of IEC 60079 is concerned with the identification and classification of areas where
explosive dust atmospheres and combustible dust layers are present, in order to permit the
proper assessment of ignition sources in such areas.
In this standard, explosive dust atmospheres and combustible dust layers are treated
separately. In Clause 4, area classification for explosive dusts clouds is described, with dust
layers acting as one of the possible sources of release. In Clause 7 other general
considerations for dust layers are described.
The examples in this standard are based on a system of effective housekeeping being
implemented in the plant to prevent dust layers from accumulating. Where effective
housekeeping is not present, the area classification includes the possible formation of
explosive dust clouds from dust layers.
The principles of this standard can also be followed when combustible fibres or flyings might
cause a hazard.
This standard is intended to be applied where there can be a risk due to the presence of
explosive dust atmospheres or combustible dust layers under normal atmospheric conditions
(see Note 1).
NOTE 1 Atmospheric conditions include variations in pressure and temperature above and below reference levels
of 101,3 kPa (1 013 mbar) and 20 °C (293 K), provided that the variations have a negligible effect on the explosive
properties of the combustible materials.
It does not apply to
– underground mining areas,
– dusts of explosives that do not require atmospheric oxygen for combustion such as
pyrophoric substances, propellants, pyrotechnics, munitions, peroxides, oxidizers, waterreactive
elements or compounds, or other similar materials.
– catastrophic failures which are beyond the concept of abnormality dealt with in this
standard,
– any risk arising from an emission of toxic gas from the dust.
This standard does not apply to where a hazard might arise due to the presence of flammable
gas or vapour, but the principles may be used in the assessment of a hybrid mixture (see also
IEC 60079-10-1).
NOTE 2 Additional guidance on hybrid mixtures is provided in Annex C.
This standard does not take into account the effects of consequential damage following a fire
or an explosion.

EN IEC 60079-14 contains the specific requirements for the design, selection, erection and initial inspection of electrical installations in, or associated with, explosive atmospheres. Where the equipment is required to meet other environmental conditions, for example, protection against ingress of water and resistance to corrosion, additional protection requirements may be necessary. The requirements of this standard apply only to the use of equipment under standard atmospheric conditions as defined in IEC 60079-0. For other conditions, additional precautions may be necessary, and the equipment should be certified for these other conditions. For example, most flammable materials and many materials which are normally regarded as non-flammable might burn vigorously under conditions of oxygen enrichment. These requirements are in addition to the requirements for installations in non-hazardous areas. This standard applies to all electrical equipment including fixed, portable, transportable and personal, and installations, permanent or temporary. This standard does not apply to - electrical installations in mines susceptible to firedamp; No account is taken in this Standard of the toxic risks that are associated with flammable gases, liquids and dusts in concentrations that are usually very much less than the lower explosive limit. In locations where personnel may be exposed to potentially toxic concentrations of flammable material, appropriate precautions should be taken. Such precautions are outside the scope of this Standard.

This part of the IEC 60079 series applies to users and covers factors directly related to the inspection and maintenance of electrical installations within hazardous areas only, where the hazard may be caused by flammable gases, vapours, mists, dusts, fibres or flyings. It does not include: - other fundamental installation and inspection requirements for electrical installations; - the verification of electrical equipment; - the repair and reclamation of explosion protected equipment (see IEC 60079-19). This standard supplements the requirements of IEC 60364-6. In the case of dusts, fibres or flyings the level of housekeeping may influence the inspection and maintenance requirements. This standard is intended to be applied where there can be a risk due to the presence of explosive gas or dust mixtures with air or combustible dust layers under normal atmospheric conditions. It does not apply to: - underground mining areas, - dusts of explosives that do not require atmospheric oxygen for combustion, - pyrophoric substances.

Inerting is a measure to prevent explosions. By feeding inert gas into a system which is to be protected against an explosion, the oxygen content is reduced below a certain concentration until no explosion can occur. The addition of sufficient inert gas to make any mixture non-flammable when mixed with air (absolute inerting) is only required in rare occasions. The requirements for absolute inerting will be discussed. Inerting may also be used to influence the ignition and explosion characteristics of an explosive atmosphere.
The guidance given on inerting is also applicable to prevent an explosion in case of a fire.
The following cases are not covered by the guideline:
-   admixture of an inert dust to a combustible dust;
-   inerting of flammable atmospheres by wire mesh flame traps in open spaces of vessels and tanks;
-   fire fighting;
-   avoiding an explosive atmosphere by exceeding the upper explosion limit of a flammable substance.
Inerting which is sufficient to prevent an explosion is not a protective measure to prevent fires, self-ignition, exothermic reactions or a deflagration of dust layers and deposits.

PWI created for possible future // procedures * D146/019: CLC/SC 31-1 declared dormant, all active WIs transferred to CLC/TC 31.

This European Standard specifies methods for the identification and assessment of hazardous situations leading to explosion and the design and construction measures appropriate for the required safety. This is achieved by:
   hazard identification;
   risk assessment;
   reduction of risk;
   information for use.
The safety of equipment, protective systems and components can be achieved by eliminating of hazards and/or limiting the risk, i.e. by:
a)   design without using safeguarding;
b)   safeguarding;
c)   communication links if necessary to convey information to the user;
d)   any other precautions.
Measures in accordance with a) (prevention) and b) (protection) against explosions are dealt with in Clause 6, measures according to c) against explosions are dealt with in Clause 7. Measures in accordance with d) are not specified in this European Standard. They are dealt with in EN ISO 12100-1:2003, Clause 5.
The preventive and protective measures described in this European Standard will not provide the required level of safety unless the equipment, protective systems and components are operated within their intended use and are installed and maintained according to the relevant codes of practice or requirements.
This standard specifies general design and construction methods to help designers and manufacturers in achieving explosion safety in the design of equipment, protective systems and components.
This European Standard is applicable to any equipment, protective systems and components intended to be used in potentially explosive atmospheres, under atmospheric conditions. These atmospheres can arise from flammable materials processed, used or released by the equipment, protective systems and components or from materials in the vicinity of the equipment, protective systems and components and/or from the materials of construction of the equipment, protective systems and components.