oSIST prEN 14983:2021

Explosion prevention and protection in underground mines - Equipment and protective systems for firedamp drainage

This standard specifies the requirements for equipment for firedamp drainage. That equipment can consist of ventilators, pressure generators and safety facilities. This standard also specifies requirements for the installation and monitoring of this equipment.

Explosionsschutz in untertägigen Bergwerken - Geräte und Schutzsysteme zur Absaugung von Grubengas

Prévention de l’explosion et protection contre l’explosion dans les mines souterraines - Appareils et systèmes de protection destinés au captage du grisou

Preprečevanje eksplozij in zaščita v podzemnih rudnikih - Oprema in zaščitni sistemi za odvajanje jamskega plina

General Information

• Status: Not Published
• Public Enquiry End Date: 29-Nov-2021
• ICS: 13.230 - Explosion protection
• ICS: 73.100.20 - Ventilation, air-conditioning and illumination equipment
• Technical Committee: EXP - Electrical apparatus for explosive atmospheres
• Current Stage: 4020 - Public enquire (PE) (Adopted Project)
• Start Date: 01-Oct-2021
• Due Date: 18-Feb-2022
• Directive: 2014/34/EU - Directive 2014/34/EU Of The European Parliament And Of The Council of 26 February 2014 on the harmonisation of the laws of the Member States relating to equipment and protective systems intended for use in potentially explosive atmospheres (recast)
• Mandate: M/BC/CEN/92/46 - Standardization mandate assigned to CEN/CENELEC concerning equipment and protective systems intended for use in potentially explosive atmospheres
• Ref Project: prEN 14983 - Explosion prevention and protection in underground mines - Equipment and protective systems for firedamp drainage

RELATIONS

• Revised: SIST EN 14983:2007 - Explosion prevention and protection in underground mines - Equipment and protective systems for firedamp drainage
• Effective Date: 26-Dec-2018

Standards Content (sample)

SLOVENSKI STANDARD
oSIST prEN 14983:2021
01-november-2021
Preprečevanje eksplozij in zaščita v podzemnih rudnikih - Oprema in zaščitni
sistemi za odvajanje jamskega plina

Explosion prevention and protection in underground mines - Equipment and protective

systems for firedamp drainage
Explosionsschutz in untertägigen Bergwerken - Geräte und Schutzsysteme zur
Absaugung von Grubengas

Prévention de l’explosion et protection contre l’explosion dans les mines souterraines -

Appareils et systèmes de protection destinés au captage du grisou
Ta slovenski standard je istoveten z: prEN 14983
ICS:
13.230 Varstvo pred eksplozijo Explosion protection
73.100.20 Prezračevalna, Ventilation, air-conditioning
klimatizacijska in and illumination equipment
razsvetljevalna oprema
oSIST prEN 14983:2021 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN 14983:2021
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oSIST prEN 14983:2021
DRAFT
EUROPEAN STANDARD
prEN 14983
NORME EUROPÉENNE
EUROPÄISCHE NORM
September 2021
ICS 73.100.20 Will supersede EN 14983:2007
English Version
Explosion prevention and protection in underground
mines - Equipment and protective systems for firedamp
drainage

Prévention de l'explosion et protection contre Explosionsschutz in untertägigen Bergwerken - Geräte

l'explosion dans les mines souterraines - Appareils et und Schutzsysteme zur Absaugung von Grubengas

systèmes de protection destinés au captage du grisou

This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee

CEN/TC 305.

If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations

which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.

This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other

language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC

Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,

Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,

Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and

United Kingdom.

Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are

aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without

notice and shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 14983:2021 E

worldwide for CEN national Members.
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Contents Page

European foreword ............................................................................................................................................. 4

Introduction .......................................................................................................................................................... 5

1 Scope .......................................................................................................................................................... 6

2 Normative references .......................................................................................................................... 6

3 Terms and definitions ......................................................................................................................... 6

4 Equipment and protective systems for firedamp drainage ................................................... 9

4.1 General ...................................................................................................................................................... 9

4.2 Borehole standpipes ............................................................................................................................ 9

4.3 Drainage pipes for seals and stoppings ......................................................................................12

4.4 Water separators at drainage points ...........................................................................................12

4.5 Firedamp pipes ....................................................................................................................................12

4.5.1 General requirements for firedamp pipes .................................................................................12

4.5.2 Measuring points for measuring equipment in firedamp drainage pipes .....................12

4.6 Pressure vessels in firedamp drainage plant ............................................................................12

4.7 Pressure generators ...........................................................................................................................13

4.7.1 Requirements for pressure generators ......................................................................................13

4.7.2 Reserve pressure generators ..........................................................................................................13

4.7.3 Location of pressure generators ....................................................................................................13

4.8 Venting of the drained firedamp ...................................................................................................14

4.9 Flame arresters in pipelines ...........................................................................................................14

4.9.1 Flame arresters ....................................................................................................................................14

4.9.2 Non-flammable firedamp vent pipe outlets ..............................................................................15

4.9.3 Non-flammable drainage pipe ........................................................................................................16

4.9.4 Protection of gas utilization plant .................................................................................................16

4.9.5 Reserve container and operating state .......................................................................................16

4.10 Requirements for the design of electrical safety devices .....................................................17

4.11 Electrostatic ignition risks ...............................................................................................................17

5 Instructions for installation and use ............................................................................................17

Annex A (informative) Installation and use of firedamp drainage system .................................18

A.1 General ....................................................................................................................................................18

A.2 Work on firedamp pipes ...................................................................................................................18

A.3 Measures to be taken when gas levels fall below or exceed limit values during

firedamp drainage ..............................................................................................................................19

A.4 Failure or shutdown of pressure generators ............................................................................19

Annex B (normative) Monitoring of firedamp drainage system .....................................................20

B.1 Examination and inspection by competent persons ..............................................................20

B.2 Measurement of the drained firedamp mixture and pressure ...........................................20

B.2.1 Measurements taken by hand ........................................................................................................20

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B.2.2 Fixed monitoring equipment.......................................................................................................... 20

B.3 Documentation .................................................................................................................................... 21

B.4 Firedamp circuit plan ........................................................................................................................ 21

Annex C (normative) Requirements for location of pressure generators .................................. 22

Annex D (normative) Requirements for degassing equipment for abandoned surface

openings ................................................................................................................................................. 23

Annex E (informative) Example for calculation of t -path .............................................................. 27

E.1 General ................................................................................................................................................... 27

E.2 Example for calculation of t90-path .............................................................................................. 27

Annex F (informative) Significant Changes between this European Standard and

EN 14983:2007 .................................................................................................................................... 29

Annex ZA (informative) Relationship between this European Standard and the essential

requirements of Directive 2014/34/EU aimed to be covered ........................................... 31

Bibliography ....................................................................................................................................................... 32

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European foreword

This document (prEN 14983:2021) has been prepared by Technical Committee CEN/TC 305 “Potentially

explosive atmospheres — Explosion prevention and protection”, the secretariat of which is held by DIN.

This document is currently submitted to the CEN Enquiry.
This document will supersede EN 14983:2007.

This document has been prepared under a Standardization Request given to CEN by the European

Commission and the European Free Trade Association, and supports essential requirements of EU

Directive(s) / Regulation(s).

For relationship with EU Directive(s) / Regulation(s), see informative Annex ZA, which is an integral part

of this document.
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Introduction

Firedamp drainage is a technical process for selected gas removal, the purpose of which is to reduce the

risks presented by inflammable gas and air mixtures. Firedamp drainage is therefore a measure for

preventive explosion protection.

In the mining industry, firedamp is drained from the underground workings of gassy mines, from

boreholes and abandoned mine workings to ensure that mine workers are not exposed to the risks

associated with the occurrence of an explosive atmosphere at their place of work. In this case, the

explosion risk results from unacceptable accumulations of firedamp occurring in the waste areas and

cavities left in the in the rock strata after the coal has been extracted from the coal seam. In such cases,

the need to drain these accumulations, and the complexity of the drainage system, depends on the amount

of firedamp produced by the coal and the likelihood of it occurring in explosive quantities in the mine

roadways and coal face. Examples of situations that might cause firedamp to move in dangerous

concentrations from the waste area or cavities into the mine roadways: a breakdown of the mine

ventilation system or a sudden reduction in the underground atmospheric pressure. National legislation

in EU coal mining member countries requires workers to be withdrawn to a safe place if firedamp levels

attain a specific nationally defined value in the general body of mine air. Firedamp drainage is therefore

often used in gassy mines in an attempt to ensure that the concentration of firedamp in the general body

of mine air is kept well below this critical level, even during abnormal situations such as those described

above.

Once the accumulations of firedamp have been drained from the affected areas, it is usually discharged

to the mine surface, but in some cases it is discharged into the mine return ventilation system. In systems

where the firedamp is brought to the mine surface, it is discharged to the atmosphere through an earthed

metallic discharge stack or pressurized and delivered to a utilization system, such as a gas-fired boiler.

In abandoned mines, firedamp drainage is used

— to prevent gas pressure building up and gas issuing at the surface in an uncontrolled manner, and

— to protect workers at an adjacent nearby mine, or

— to allow it to be utilized, for example by burning it in a gas-fired boiler to produce heat or to generate

electricity.
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1 Scope

This document specifies the requirements for equipment and protective systems for firedamp drainage

at mines. It also contains requirements for the construction and monitoring of this equipment and

protective systems (see EN 1127-2:2014).

This document does not apply to firedamp utilization systems beyond the utilization shut-off device.

2 Normative references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements of this document. For dated references, only the edition cited applies. For

undated references, the latest edition of the referenced document (including any amendments) applies.

EN 1127-2:2014, Explosive atmospheres - Explosion prevention and protection - Part 2: Basic concepts and

methodology for mining

EN 13237:2012, Potentially explosive atmospheres — Terms and definitions for equipment and protective

systems intended for use in potentially explosive atmospheres

EN 61508:2010, (all parts), Functional safety of electrical/electronic/programmable electronic safety-

related systems

EN ISO 16852:2016, Flame arresters - Performance requirements, test methods and limits for use (ISO

16852:2016)

EN ISO/IEC 80079-38:2016, Explosive atmospheres - Part 38: Equipment and components in explosive

atmospheres in underground mines (ISO/IEC 80079-38:2016)
3 Terms and definitions

For the purposes of this document, the terms and definitions given in EN 1127-2:2014 and

EN 13237:2012 and the following apply:

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at http://www.iso.org/obp
3.1
electrostatic leakage resistance
electrical resistance measured between an object and earth
3.2
active explosion isolation system

system which is designed to be activated by a detector and control and indicating equipment (CIE) which

are inherent parts of the system and stop explosions from travelling through pipelines or limit destructive

effects of the explosion
[SOURCE: EN 15089:2009, 3.7.1]
3.3
starting by-pass

temporary and specific by-passing of a safety device when starting the pressure generator of a firedamp

drainage plant
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3.4
design pressure

pressure at the top of each chamber of the pressure equipment chosen for the derivation of the calculation

pressure of each component
[SOURCE: EN 764-1:2015+A1:2016, 3.2.33]
3.5
firedamp

any potentially explosive mixture of flammable gases naturally occurring in a mine

Note 1 to entry: As firedamp consists mainly of methane, the terms “firedamp” and “methane” are used frequently

in mining practice as synonyms.
[SOURCE: EN 1127-2:2014, 3.1]
3.6
firedamp collector pipe
gas pipes connected directly to one or more boreholes or gas drainage points
3.7
firedamp mains pipe
gas pipes connected to more than one gas collector pipe
3.8
extinguishing system

system that is used to discharge suppressant agent to extinguish flame and keep it from propagating into

the vent pipe
3.9
technically leaktight
made in such a way that no changes in gas composition occur

Note 1 to entry: Gas pipes, items of plant and equipment, including all detachable and non-detachable connections

can be technically leaktight.

Note 2 to entry: The term “technically leaktight” means that diffusion through statically stressed seals can occur.

3.10
-path
t90
distance between the monitoring position and the shut-off device

Note 1 to entry: This distance depends on the measured gas/air mixture, taking account of the velocity of flow, the

response time (according to EN 61779-29-1:2016) of the measurement device, the tripping time and the closing

time of the rapid shut-off device; the response time is the time taken to achieve 90 % of the final indication.

3.11
flame arrester

device fitted to the opening of an enclosure, or to the connecting pipe work of a system of enclosures, and

whose intended function is to allow the flow but prevent the transmission of flame

[SOURCE: EN ISO 16852:2016, 3.1]
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3.12
flame arrester element

portion of a flame arrester whose principal function is to prevent flame transmission

[SOURCE: EN ISO 16852:2016, 3.3]
3.13
endurance burning
stabilized burning for an unlimited time
[SOURCE: EN ISO 16852:2016, 3.6]
3.14
endurance flame arrester

flame arrester that prevents flame transmission during and after endurance burning

[SOURCE: EN ISO 16852:2016]
3.15
short time burning
stabilized burning for a specified time
[SOURCE: EN ISO 16852:2016, 3.16]
3.16
short-time burning proofed deflagration flame arrester

flame arrester designed to prevent the transmission of an atmospheric deflagration and during and after

short-time burning

Note 1 to entry: In this case designed as end-of-line flame arrester (at the end of a pipe work), that means end-of-

line deflagration flame arrester. Equipped with an integrated temperature sensor that emits a signal suitable for

initiating countermeasures.
3.17
detonation
explosion propagating at supersonic velocity and characterized by a shock wave
[SOURCE: ISO 8421-1:1987, 1.12]
3.18
detonation flame arrester
flame arrester designed to prevent the transmission of a detonation

Note 1 to entry: In this case designed as in-line flame arrester for stable detonations, that means in-line detonation

flame arrester.
[SOURCE: EN ISO 16852:2016, 3.15]
3.19
deflagration
explosion propagating at subsonic velocity
[SOURCE: ISO 8421-1:1987, 1.11]
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3.20
deflagration flame arrester
flame arrester designed to prevent the transmission of a deflagration

Note 1 to entry: In this case designed as in-line flame arrester, that means in-line deflagration flame arrester.

[SOURCE: EN ISO 16852:2016, 3.14]
3.21
pre-volume flame arrester

flame arrester that, after ignition by an internal ignition source, prevents flame transmission from inside

an explosion-pressure-resistant containment (e.g. a vessel or closed pipe work) to the outside, or into the

connecting pipe work

Note 1 to entry: In this case the explosion-pressure-resistant containment would be the housing of the pressure

generator.

[SOURCE: EN ISO 16852:2016, 3.23 – modified: admitted term deleted and Note 1 to entry changed]

4 Equipment and protective systems for firedamp drainage
4.1 General

Electrical and mechanical equipment used in firedamp drainage shall not pose an explosion risk. For this

reason:

— equipment used in the firedamp drainage systems where flammable gas is likely to occur shall be

explosion protected either Group I Category M1 or M2, or, if on the surface, Group II Category 1 or 2;

— where measuring equipment is in direct contact with firedamp/air concentration within the

explosive range (e.g. the purity measuring instruments), it shall be category M1 ignition protected.

In surface installations, Group II, Category 1 equipment may be used;

— the drainage system shall have a facility to allow it to be shut down, usually automatically, where the

concentration of extracted firedamp in the pipework reaches a prescribed limit, taking into account

the response time of the monitoring equipment and the t -path (see Annex E).

NOTE 1 Care is needed during start-up of the firedamp drainage system when the pipework will be full of air and

will at some stage pass through the explosive range.

NOTE 2 Normally, the explosive range for firedamp/air mixtures is specified within a range of about 5 % by

volume to 15 % by volume methane. Automatic shutdown usually takes place when a methane concentration

reaches a level of approx. 22 % by volume.
4.2 Borehole standpipes

Standpipes shall be made in such a way that devices (Y- or T-pieces) for the insertion of borehole probes

can be attached to them. The standpipe shall have connection facilities to allow it to be connected, it shall

be made in such a way and arranged so that no reduction in cross-section occurs, and should contain a

suitable facility for measuring the volume flow and vacuum pressure where the boreholes are accessible

for measuring and taking firedamp samples, e.g. a measuring section (see Figure 1, Figure 2, Figure 3 and

Figure 4).
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Key
d diameter 5 facility for measurements
1 borehole standpipe 6 facility for measurements
2 flexible hose suitable for the required flow and pressure 7 measuring section
3 T-piece 8 collector pipe
4 connection for water separator 9 shut-off device

Figure 1 — Example of connection of roof borehole to collector pipe when measurement and

control are accessible
Key
1 borehole standpipe
2 flexible hose suitable for the required flow and pressure
3 collector pipe
4 shut-off device
5 suitable connection for collector pipe

Figure 2 — Example of connection of roof borehole to collector pipe when measurement and

control are not accessible
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Key
d diameter 5 facility for measurements
1 borehole standpipe 6 facility for measurements
2 flexible hose suitable for the required flow and pressure 7 measuring section
3 T-piece 8 shut-off device
4 connection for water separator 9 collector pipe

Figure 3 — Example of connection of floor borehole to collector pipe when measurement and

control are accessible
Key
1 borehole standpipe
2 flexible hose suitable for the required flow and pressure
3 collector pipe
4 shut-off device
5 suitable connection for collector pipe
6 water separator

Figure 4 — Example of connection of floor borehole to collector pipe when measurement and

control are not accessible
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4.3 Drainage pipes for seals and stoppings

When firedamp drainage pipes are installed in seals and stoppings to drain methane, pipes shall be of

sufficient diameter, equipped with devices for controlling firedamp flows and be monitored in

accordance with 4.2.

The requirements of 4.2 are to be applied accordingly for gas measuring devices in seals and stoppings.

4.4 Water separators at drainage points

Where water is a problem, water separators should be provided between the drainage points and the

measuring sections. These separators shall be made in such a way that they can separate any water that

collects in the gas pipe without allowing the admission of the ambient atmosphere.

4.5 Firedamp pipes
4.5.1 General requirements for firedamp pipes

Firedamp pipes and their fittings (e.g. shut-off devices, controls, borehole connections) shall comply at

least with the nominal pressure stage PN 6 (see EN 1333). This strength rating is sufficient provided that

the permissible operating pressure in the gas drainage plant, based on the design of the pressure

generator and/or regulating equipment, does not exceed 0,3 bar.

Firedamp pipes shall only be fitted with pipe connections which are deemed suitable and necessary for

operation and control purposes.

Shut-off devices shall be provided in firedamp pipes in such a way that each branch pipe can be shut off

independently.

With the exception of the drainage points, all pipes shall be manufactured exclusively from materials

suitable for the transportation of methane underground.

Firedamp pipes shall be installed in such a manner as to be protected from damage.

Where necessary, vertical firedamp pipes shall be secured by the fitting of expansion pieces.

Firedamp pipes are to be positioned in such a way that any water which collects in the pipes can be

removed. Connections for water separators are to be provided at the lowest points and in the transfer

zone between the horizontal and the vertical pipe sections.

Where required, firedamp pipes are to be protected from the effects of frost and freezing.

4.5.2 Measuring points for measuring equipment in firedamp drainage pipes

Measuring points shall be provided at all places where the gas collector pipe joins a firedamp drainage

main and where the firedamp main enters a mine shaft. A damping section of at least 10 × d shall be

maintained in front of the measuring point, and a further damping section of at least 5 × d behind it.

Measuring points in firedamp main pipes, installed for monitoring pipes for leakage, shall be sited at a

minimum distance of 70 × d behind points where the firedamp collector pipes join.

The dimensions of the measuring points shall be determined on the basis of the measuring equipment

being installed.
4.6 Pressure vessels in firedamp drainage plant

Where pressure vessels are used in firedamp drainage plants the design pressure p of pressure vessels

shall be at least 6 bar pressure.

NOTE Systems operating below 0,5 bar pressure are not considered to be pressure systems.

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4.7 Pressure generators
4.7.1 Requirements for pressure generators

Each pressure generator shall have a manufacturer’s certificate stating that its housing has withstood a

water-pressure test for at least a 6 bar design pressure.
NOTE For further information see Directive 2014/68/EU

For materials of pressure generators, requirements for fans according to EN ISO/IEC 80079-38:2016, 5.3

shall be applied.

Where pressure generators operate below 0,5 bar pressure, they shall be tested in accordance with the

manufacturer's requirements.

Pressure generators shall be fitted with a temperature limiting device at the gas exit side according to the

maximum permissible operating temperature recommended by the manufacturer, unless other technical

measures can be used to prevent the permissible operating temperatures from being exceeded. The

limiting device shall be adjusted so that the maximum permissible compression temperature specified

by the manufacturer cannot be exceeded. Fluid-ring pressure generators shall be monitored so that they

are shut down automatically and immediately in the event of fluid deficiency. At the same time as this

shut-down, an audible and visual warning signal shall also be emitted at the permanently manned

position (see A.4).

Pressure generators (e.g. rotary compressors, fluid-ring pressure generators and discharge nozzles) and

pipe mains shall be designed so that a sufficient vacuum is available at each firedamp drainage point.

Where practicable, pressure generators shall be fitted additionally with:
— inlet and outlet gas pressure monitors;
— indicators showing the state of all inlet, outlet and bypass valves;

— mechanical fault monitoring (including driving motor) including an audible and visual warning

signal;
— indicators showing the state of power supply to driving motors.

All devices intended to automatically cut off power supply shall be designed so that they can only be reset

at the location of the pressure generator.

The control system shall ensure, that pressure generators cannot be started unless the outlet valve is

open, and if the outlet valve closes while the pressure generator is running the pressure generator is shut

down.
4.7.2 Reserve pressure generators

Pressure generators shall be designed in such a way that they can be changed easily due to maintenance

or after breakdown.
The number of pressure generators should be sufficient to cater for the
...