UL 60079-29-2
Explosive Atmospheres - Part 29-2: Gas Detectors - Selection, Installation, Use and Maintenance of Detectors for Flammable Gases and Oxygen

Edition Number:2SCC Approved:--
Edition Date:2018-10-15DOD Approved: --
Price Code:EANSI Approved: 2018-10-15


    1 Scope

    1DV.1 Modification of Clause 1, first paragraph to replace with the following:

    1DV.1.1 This part of IEC 60079-29 standard gives guidance on, and recommended practice for, the selection, installation, safe use and maintenance of electrically operated Group II equipment intended for use in industrial and commercial safety applications and Group I equipment in underground coal mines for the detection and measurement of flammable gases complying with the requirements of IEC 60079-29-1 or IEC 60079-29-4.

    This standard is applicable for oxygen measurement for the purpose of inertisation where explosion protection is provided by the exclusion of oxygen instead of measuring the flammable gases or vapours present. A similar application is measuring oxygen when inertising a goaf (mined out) area in an underground coal mine.

    This standard is a compilation of practical knowledge to assist the user, and applies to equipment, instruments and systems that indicate the presence of a flammable or potentially explosive mixture of gas or vapour with air by using an electrical signal from a gas sensor to produce a meter reading, to activate a visual or audible pre-set alarm or other device, or any combination of these.

    Such equipment may be used as a means of reducing the risk whenever there is the possibility of a risk to life or property specifically due to the accumulation of a flammable gas-air mixture, by providing such warnings. It may also be used to initiate specific safety precautions (e.g. plant shutdown, evacuation, fire extinguishing procedures).

    This standard is applicable to fixed installations and transportable equipment. Similarly it is applicable to the safe use of portable equipment. Since much modern equipment of this type also includes oxygen deficiency detection and/or specific toxic gas sensors, some additional guidance is given for these topics.

    For the purposes of this standard, except where specifically stated otherwise, flammable gases include flammable vapours.

    Mists are not covered by this standard due to measurement techniques currently used.

    This standard applies to Group II equipment (i.e. equipment intended for use in industrial and commercial safety applications, involving areas classified in accordance with IEC 60079-10-1) and Group I equipment.

    For the purposes of this standard, equipment includes

    a) fixed equipment including equipment mounted on a vehicle;

    b) transportable equipment; and

    c) portable equipment.

    This standard is not intended to cover, but may provide useful information, for the following:

    a) equipment intended only for the detection of non-flammable toxic gases;

    b) equipment of laboratory or scientific type intended only for analysis or measurement purposes;

    c) equipment intended only for process control applications;

    d) equipment intended for applications in explosives processing and manufacture;

    e) equipment intended for the detection of a explosive atmosphere resulting from dust or mist in air.

    1DV.2 Addition of 1DV.2.1

    1DV.2.1 Where references are made to other IEC 60079 standards, the reference requirements found in these standards apply as modified by any applicable U.S. National Differences.

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    • Cover
    • Transmittal
    • UL Harmonized Standard Title Page
    • Table of Contents
    • Deviations
    • IEC Foreword
    • Introduction
      • Explosive Atmospheres – Part 29-2: Gas Detectors – Selection, Installation, Use and Maintenance of Detectors for Flammable Gases and Oxygen
        • 1 Scope
        • 2 Normative references
        • 3 Definitions
          • 3.1 Gas properties and other physics
          • 3.2 Types of equipment
          • 3.3 Sensors and detectors
          • 3.4 Supply of gas to instruments
          • 3.5 Signals and alarms
          • 3.6 Times, checks and equipment behaviour
          • 3.7 Terms exclusive to open path equipment
        • 4 Basic information on the properties, behaviour, gases and vapours, and specific applications of gas detection
          • 4.1 Detecting gases and vapours
          • 4.2 Some common properties of gases and vapours
          • 4.3 The differences between detecting gases and vapours
          • 4.4 Oxygen deficiency
          • 4.5 Specific applications of gas detection
          • 4.6 Specific considerations for open path detection
        • 5 Measuring principles
          • 5.1 General
          • 5.2 Catalytic sensors
          • 5.3 Thermal conductivity sensors
          • 5.4 Infrared sensors
          • 5.5 Semiconductor sensors
          • 5.6 Electrochemical sensors
          • 5.7 Flame ionization detectors (FID)
          • 5.8 Flame temperature analysers (FTA)
          • 5.9 Photo ionisation detector (PID)
          • 5.10 Paramagnetic oxygen detector
        • 6 Selection of equipment
          • 6.1 General
          • 6.2 Selection criteria
          • 6.3 Miscellaneous factors affecting selection of equipment
        • 7 Behaviour of gas releases
          • 7.1 Nature of a release
          • 7.2 Buildings and enclosures
          • 7.3 Environmental considerations
        • 8 Design and installation of fixed gas detection systems
          • 8.1 General
          • 8.2 Basic considerations for the installation of fixed systems
          • 8.3 Location of detection points
          • 8.4 Access for calibration and maintenance
          • 8.5 Additional considerations for sample lines
          • 8.6 Additional considerations for open path equipment
          • 8.7 Summary of considerations for the location of measuring points and open paths
          • 8.8 Installation of measuring point and open path equipment
          • 8.9 Integrity and safety of fixed systems
          • 8.10 Timing of installation during construction operations
          • 8.11 Commissioning
          • 8.12 Operating instructions, plans and records
        • 9 Use of portable and transportable flammable gas detection equipment
          • 9.1 General
          • 9.2 Initial and periodic check procedures for portable and transportable instrumentation
          • 9.3 Guidance on the use of portable and transportable equipment
        • 10 Training of operational personnel
          • 10.1 General
          • 10.2 General training – Basic limitations and safety
          • 10.3 Operator training
          • 10.4 Maintenance training
        • 11 Maintenance, routine procedures and general administrative control
          • 11.1 General
          • 11.2 Operational checks
          • 11.3 Maintenance
          • 11.4 Sensors
          • 11.5 Flow systems
          • 11.6 Readout devices
          • 11.7 Alarms
          • 11.8 Calibration
    • Annex A(normative)Measuring principles
    • Annex B(informative)Environmental parameters
    • Annex C(informative)Typical environmental and application check-list for flammable gas detectors(for both Group I and Group II equipment)
    • Annex D (informative)Typical instrument maintenance record for flammable gas detectors
    • Annex E(informative)Atmospheric visibility(applicable to open path equipment)
    • Bibliography