Test gases - Test pressures - Appliance categories

This document specifies the test gases, test pressures and categories of appliances relative to the use of gaseous fuels of the first, second and third families. It serves as a reference document in the specific standards for appliances.
The document makes recommendations for the use of the gases and pressures to be applied for the tests of appliances burning gaseous fuels.
NOTE   Procedures for tests are given in the corresponding appliance standards. The test gases and the test pressures specified in this standard are in principle intended to be used with all types of appliances.
However, the use of some test gases and test pressures may not be appropriate in the following cases:
-   appliances with nominal heat input greater than 300 kW;
-   appliances constructed on site;
-   appliances in which the final design is influenced by the user;
-   appliances constructed for use with high supply pressures (notably direct use of the saturated vapour pressure).
In these cases, the specific appliance standards may specify other test conditions in order to establish compliance with their requirements.

Prüfgase - Prüfdrücke - Gerätekategorien

Dieses Dokument legt die Prüfgase, Prüfdrücke und Gerätekategorien für die Verwendung von Brenngasen der ersten, zweiten und dritten Gasfamilie fest. Es dient als Referenzdokument für die speziellen Gerätenormen.
Das Dokument enthält Empfehlungen zur Verwendung von Gasen und Drücken bei der Durchführung der Prüfungen. Das vollständige Verfahren wird in den entsprechenden Gerätenormen angegeben.
ANMERKUNG   Prüfverfahren werden in den zugehörigen Gerätenormen angegeben. Die Prüfgase und Prüfdrücke, die in dieser Norm festgelegt werden, sind im Prinzip für sämtliche Geräte bestimmt.
Die Verwendung der Prüfgase und Prüfdrücke kann jedoch in folgenden Fällen nicht geeignet sein:
- Geräte mit einer Nennwärmebelastung über 300 kW;
- Geräte, die vor Ort erstellt werden;
- Geräte, deren Endausführung durch den Benutzer beeinflusst wird;
- Geräte, die für einen Betrieb bei hohen Versorgungsdrücken ausgelegt sind (insbesondere die direkte Verwendung des gesättigten Dampfdruckes).
In diesen Fällen können die einzelnen Gerätenormen weitere Prüfbedingungen festlegen, um die Konformität mit den Anforderungen der entsprechenden Normen sicherzustellen.

Gaz d'essais - Pressions d'essais - Catégories d'appareils

Le présent document définit les gaz d'essai, pressions d'essai et catégories d'appareils relatifs à l'utilisation de combustibles gazeux des première, deuxième et troisième familles. Il sert de document de référence dans les normes particulières d'appareils.
Le document donne des recommandations pour l'utilisation des gaz et pressions à appliquer pour les essais des appareils brûlant des combustibles gazeux.
NOTE   Les modes opératoires pour les essais sont donnés dans les normes relatives aux appareils. Les gaz d'essai et les pressions d'essai spécifiés dans la présente norme sont, en principe, destinés à être utilisés avec tous les types d'appareils. .
Néanmoins, l'utilisation de certains gaz d'essai et pressions d'essai peut ne pas être appropriée avec les appareils suivants :
-   appareils de débit calorifique nominal supérieur à 300 kW ;
-   appareils construits sur site ;
-   appareils dont la conception finale est influencée par l'utilisateur ;
-   appareils construits pour utilisation avec de hautes pressions d'alimentation (notamment utilisation directe de la pression de vapeur saturante).
Dans ces cas, les normes particulières relatives aux appareils peuvent spécifier d'autres conditions d'essais afin d'établir la conformité avec leurs exigences.

Preskusni plini - Preskusni tlaki - Kategorije naprav

General Information

Status
Published
Current Stage
6060 - Definitive text made available (DAV) - Publishing
Due Date
21-Apr-2021
Completion Date
21-Apr-2021

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SLOVENSKI STANDARD
SIST EN 437:2021
01-julij-2021
Nadomešča:
SIST EN 437:2019
Preskusni plini - Preskusni tlaki - Kategorije naprav
Test gases - Test pressures - Appliance categories
Prüfgase - Prüfdrücke - Gerätekategorien
Gaz d'essais - Pressions d'essais - Catégories d'appareils
Ta slovenski standard je istoveten z: EN 437:2021
ICS:
27.060.20 Plinski gorilniki Gas fuel burners
91.140.40 Sistemi za oskrbo s plinom Gas supply systems
SIST EN 437:2021 en,fr,de

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

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SIST EN 437:2021
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SIST EN 437:2021
EN 437
EUROPEAN STANDARD
NORME EUROPÉENNE
April 2021
EUROPÄISCHE NORM
ICS 27.060.20; 91.140.40 Supersedes EN 437:2018
English Version
Test gases - Test pressures - Appliance categories

Gaz d'essais - Pressions d'essais - Catégories Prüfgase - Prüfdrücke - Gerätekategorien

d'appareils
This European Standard was approved by CEN on 19 January 2021.

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. Up-to-date lists and bibliographical references

concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN

member.

This European Standard exists 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.
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. EN 437:2021 E

worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
SIST EN 437:2021
EN 437:2021 (E)
Contents Page

European foreword ....................................................................................................................................................... 3

1 Scope .................................................................................................................................................................... 4

2 Normative references .................................................................................................................................... 4

3 Terms and definitions ................................................................................................................................... 4

4 Gases .................................................................................................................................................................... 7

4.1 Classification in gas families and groups ................................................................................................ 7

4.2 Test gases ........................................................................................................................................................... 8

5 Test pressures ............................................................................................................................................... 12

6 Classification of appliances ...................................................................................................................... 14

6.1 Appliance categories ................................................................................................................................... 14

6.1.1 General ............................................................................................................................................................. 14

6.1.2 Category I ........................................................................................................................................................ 14

6.1.3 Category II ....................................................................................................................................................... 15

6.1.4 Category III ..................................................................................................................................................... 16

6.2 Operations permitted for a change of gas or pressure, adjustment and regulating

devices .............................................................................................................................................................. 16

7 Choice of test gases and test pressures ................................................................................................ 17

8 Marking ............................................................................................................................................................ 18

Annex A (normative) Conditions for preparation of the test gases .......................................................... 19

Annex B (informative) National situations ........................................................................................................ 20

B.1 General ............................................................................................................................................................. 20

B.2 Categories listed in the body of the standard marketed in the different countries ............. 20

B.3 Appliance supply pressures corresponding to the categories given in B.1 and B.2 ............ 23

B.4 Special categories marketed nationally or locally ........................................................................... 27

B.4.1 General ............................................................................................................................................................. 27

B.4.2 Categories ....................................................................................................................................................... 33

B.5 Test gases and test pressures corresponding to the special categories given in B.4 .......... 40

B.6 Special conditions ........................................................................................................................................ 47

B.7 National and local gas distribution specifications relevant for defining appliance

categories given in B.4 ................................................................................................................................ 54

Annex C (informative) Guidelines for extension to other categories ....................................................... 55

Annex D (informative) Relationship between the distributed gases and the corresponding test

gases .................................................................................................................................................................. 56

Bibliography ................................................................................................................................................................. 57

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SIST EN 437:2021
EN 437:2021(E)
European foreword

This document (EN 437:2021) has been prepared by Technical Committee CEN/TC 238 “Test gases, test

pressures, appliance categories and gas appliance types”, the secretariat of which is held by AFNOR.

This European Standard shall be given the status of a national standard, either by publication of an identical

text or by endorsement, at the latest by October 2021, and conflicting national standards shall be withdrawn

at the latest by October 2021.

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent

rights. CEN shall not be held responsible for identifying any or all such patent rights.

This document supersedes EN 437:2018.

EN 437 is intended to provide all the CEN Technical Committees preparing standards on gas appliances with

definitions for test gases, test pressures and categories of appliances for use by these committees within the

limits of the scope defined in Clause 1.

The document seeks to clarify the present situation with respect to test gases, test pressures and appliance

categories.

The concern for clarity has led to the elucidation of numerous categories and national situations or

conditions. The complexity of the document is likely to increase as new members join the Union.

This document can be considered as an important stage in the harmonization of test gases, test pressures and

appliance categories and the quality of information on gas usage in Europe.

In comparison with the previous version, this document incorporates updates of Table 6, Table 7, Table B.4

and some editorial changes.

Annex B gives national situations relating to gases, gas pressures and appliance categories that apply

nationally or locally. The information provided is included under the responsibility of the national

standardization bodies. The tables of Annex B give the available information. Therefore, Annex B is

informative.

According to the CEN-CENELEC Internal Regulations, the national standards organisations of the following

countries are bound to implement this European Standard: 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 the United Kingdom.

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SIST EN 437:2021
EN 437:2021 (E)
1 Scope

This document specifies the test gases, test pressures and categories of appliances relative to the use of

gaseous fuels of the first, second and third families. It serves as a reference document in the specific standards

for appliances.

The document makes recommendations for the use of the gases and pressures to be applied for the tests of

appliances burning gaseous fuels.

NOTE Procedures for tests are given in the corresponding appliance standards. The test gases and the test

pressures specified in this standard are in principle intended to be used with all types of appliances.

However, the use of some test gases and test pressures may not be appropriate in the following cases:

— appliances with nominal heat input greater than 300 kW;
— appliances constructed on site;
— appliances in which the final design is influenced by the user;

— appliances constructed for use with high supply pressures (notably direct use of the saturated vapour

pressure).

In these cases, the specific appliance standards may specify other test conditions in order to establish

compliance with their requirements.
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 ISO 3166-1:2020, Codes for the representation of names of countries and their subdivisions - Part 1: Country

code (ISO 3166-1:2020)

EN ISO 6976:2016, Natural gas - Calculation of calorific values, density, relative density and Wobbe indices from

composition (ISO 6976:2016)
3 Terms and definitions
For the purposes of this document, the following terms and definitions 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 https://www.iso.org/obp
3.1
gas appliance
appliance burning gaseous fuels

Note 1 to entry: For the purposes of this standard the term “gaseous fuels” means any fuel which is in a gaseous state

at a temperature of 15 °C under an absolute pressure of 1 bar.
3.2
distributed gas
gaseous fuel used on the territory of a CEN member
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SIST EN 437:2021
EN 437:2021(E)
3.3
test gas

gases intended for the verification of the operational characteristics of gas appliances

Note 1 to entry: Test gases include reference and limit gases.
3.4
reference gas

test gas with which appliances operate under nominal conditions when they are supplied at the

corresponding normal pressure
3.5
limit gas

test gas representative of the extreme variations in the characteristics of the gases for which appliances have

been designed
3.6
test pressure

gas pressure used to verify the operational characteristics of gas appliances, consisting of normal and limit

pressures
Note 1 to entry: Gas pressure is expressed in millibars (mbar) 1 mbar = 10 Pa.
3.7
normal pressure

pressure under which the appliances operate in nominal conditions when they are supplied with the

corresponding reference gas
3.8
limit pressure

pressure representative of the extreme variations in the appliance supply conditions

Note 1 to entry: Limit pressures comprise a maximum pressure p and a minimum pressure p .

max min
3.9
pressure couple

combination of two distinct gas distribution pressures applied by reason of the significant difference existing

between the Wobbe indices within a single family or group in which
— the higher pressure corresponds only to gases of low Wobbe index;
— the lower pressure corresponds to gases of high Wobbe index.
Note 1 to entry: The pressure couple is indicated by using the symbol (⇆).
3.10
reference conditions
conditions which correspond to 15 °C, 1 013, 25 mbar, unless otherwise specified
3.11
relative density

ratio of the masses of equal volumes of dry gas and dry air under the same conditions of temperature and

pressure: 15 °C or 0 °C and 1 013, 25 mbar
---------------------- Page: 7 ----------------------
SIST EN 437:2021
EN 437:2021 (E)
3.12
calorific value

quantity of heat produced by the complete combustion, at a constant pressure equal to 1 013,25 mbar, of a

unit volume or mass of gas, the constituents of the combustible mixture being taken at reference conditions

and the products of combustion being brought back to the same conditions
Note 1 to entry: A distinction is made between:

— the gross calorific value H : the water produced by combustion is assumed to be condensed;

— the net calorific value H : the water produced by combustion is assumed to be in the vapour state.

Note 2 to entry: The calorific value is expressed:

— either in megajoules per cubic metre (MJ/m ) of dry gas under the reference conditions;

— or in megajoules per kilogram (MJ/kg) of dry gas.
3.13
Wobbe index

ratio of the calorific value of a gas per unit volume and the square root of its relative density under the same

reference conditions

Note 1 to entry: The Wobbe index is expressed in megajoules per cubic metre (MJ/m ) of dry gas under the reference

conditions.

Note 2 to entry: The Wobbe index is said to be gross (W ) or net (W ) according to whether the calorific value used is

s i
the gross or net calorific value.
3.14
heat input

quantity of energy used in unit time corresponding to the volumetric or mass flow rates, the calorific value

used being either the net or gross calorific value
Note 1 to entry: The heat input is expressed in kilowatts (kW).
3.15
nominal heat input
value of the heat input declared by the manufacturer
3.16
mass flow rate
mass of gas consumed by the appliance in unit time during continuous operation

Note 1 to entry: The mass flow rate is expressed in kilograms per hour (kg/h) or grams per hour (g/h).

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SIST EN 437:2021
EN 437:2021(E)
3.17
volume flow rate
volume of gas consumed by the appliance in unit time during continuous operation

Note 1 to entry: The volume flow rate is expressed in cubic metres per hour (m /h), litres per minute (l/min), cubic

3 3
decimetres per hour (dm /h) or cubic decimetres per second (dm /s).
3.18
gas family

group of gaseous fuels with similar burning behaviour linked together by a range of Wobbe indices

Note 1 to entry: See Table 1.
3.19
gas group
specified range of Wobbe index within that of the family concerned

Note 1 to entry: This range is determined on the general principle that appliances using this gas group operate safely

when burning all gases within this range without adjustment.

Note 2 to entry: Adjustment of the appliance may be permitted in accordance with the special national or local

conditions that apply in some countries (see B.4). For gases corresponding to national or local conditions, see Tables

B.5, B.6 and B.7.
Note 3 to entry: See Table 1.
3.20
appliance category

means of identifying the gas families and/or gas groups for which a gas appliance is designed to operate safely

and to the desired performance level

Note 1 to entry: General appliance categories are described in 6.1. Special appliance categories marketed nationally

or locally are described in B.4.
Note 2 to entry: See individual appliance standards.
4 Gases
4.1 Classification in gas families and groups

Gases are classified into three families, each family may be divided into groups, (themselves being divided

into ranges, see Annex B), as a function of the Wobbe index, according to the values given in Table 1.

NOTE 1 See Annex D for more details.

NOTE 2 The classification given in Table 1 is used for the communication of the types of gases and corresponding

supply pressures of gaseous fuels used on the territories of Member States.
---------------------- Page: 9 ----------------------
SIST EN 437:2021
EN 437:2021 (E)

Table 1 — Classification of gas families and groups as a function of the Wobbe indices, dry gas at

15 °C and 1 013,25 mbar
Gas families and groups Gross Wobbe index, dry gas at 15 °C and 1 013,25 mbar
MJ/m
Minimum Maximum
First family
— Group a 22,4 24,8
Second family 39,1 54,7
— Group H 45,7 54,7
— Group L 39,1 44,8
— Group E 40,9 54,7
Third family 72,9 87,3
— Group B/P 72,9 87,3
— Group P 72,9 76,8
— Group B 81,8 87,3
4.2 Test gases

The composition and principal characteristics of the different test gases corresponding to the gas families or

groups are given in Tables 2 and 3.

In particular cases specified in the individual appliance standards, gas G 24, whose characteristics are given

in Table 3, may be used but only at the normal test pressure.

The calorific values of the third family gases, expressed in mega joules per cubic metre in Table 2, may also

be expressed in mega joules per kilogram of dry gas, as shown in Table 3.

The values in Tables 2 and 3, measured and expressed at 15 °C, are derived from EN ISO 6976:2016.

The conditions for the preparation of the test gases are given in Annex A.

NOTE The characteristics of second family gases at reference conditions other than 15 °C for metering and 15 °C

for combustion can be calculated using the coefficients given in EN ISO 13443:2005, Annex A (normative). As an

example, the characteristics of the reference gases of the second family at 0 °C for metering and for combustion and

1 013,25 mbar (dry gas) are given in Table 4.
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SIST EN 437:2021
EN 437:2021(E)

Table 2 — Characteristics of the test gases for the first and second families, gas dry at 15 °C and

1 013,25 mbar
Gas
family Composition
W H W H
Test gases Designation d
i i s s
and by volume
Group
c 3 3 3 3
% MJ/m MJ/m MJ/m MJ/m
Gases of the first family
Group a Reference gas G 110 CH = 26
Incomplete H = 50 21,76 13,95 24,75 15,87 0,411
combustion,
N = 24
flame lift and
sooting limit gas
Light back limit G 112 CH = 17
gas
H = 59 19,48 11,81 22,36 13,56 0,367
N = 24
Gases of the second family
Group H Reference gas G 20 CH = 100 45,67 34,02 50,72 37,78 0,555
Incomplete G 21 CH = 87 49,60 41,01 54,69 45,28 0,684
combustion and
C H = 13
3 8
sooting limit gas
Light back limit G 222 CH = 77 42,87 28,53 47,87 31,86 0,443
gas
H = 23
Flame lift limit G 23 CH = 92,5 41,11 31,46 45,66 34,95 0,586
gas
N = 7,5
Over heating G 24 CH = 68 47,01 35,70 52,09 39,55 0,577
limit gas
C H = 12
3 8
H = 20
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SIST EN 437:2021
EN 437:2021 (E)
Gas
family Composition
W H W H
Test gases Designation d
i i s s
and by volume
Group
c 3 3 3 3
% MJ/m MJ/m MJ/m MJ/m
Group L Reference gas G 25 CH = 86 37,38 29,25 41,52 32,49 0,612
light back limit
N = 14
gas
Incomplete G 26 CH = 80 40,52 33,36 44,83 36,91 0,678
combustion and
C H = 7
3 8
sooting limit gas
N = 13
Flame lift limit G 27 CH = 82 35,17 27,89 39,06 30,98 0,629
gas
N = 18
Group E Reference gas G 20 CH = 100 45,67 34,02 50,72 37,78 0,555
Incomplete G 21 CH = 87 49,60 41,01 54,69 45,28 0,684
combustion and
sooting limit gas
C H = 13
3 8
CH = 77
Light back limit G 222 42,87 28,53 47,87 31,86 0,443
gas
H = 23
CH = 85
Flame lift limit G 231 36,82 28,91 40,90 32,11 0,617
gas
N = 15
Over heating G 24 CH = 68 47,01 35,70 52,09 39,55 0,577
limit gas
C H = 12
3 8
H = 20
For gases used nationally or locally, see B.5.
For other groups, see B.5.
See also Annex A.

Limit gas used only for certain types of appliance, specified in the individual appliance standards (e.g. fully

premixed burners, forced draught burners, …).
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SIST EN 437:2021
EN 437:2021(E)

Table 3 — Characteristics of the test gases for the third family, gas dry at 15 °C and 1 013,25 mbar

Gas
family Composition
W H W H
Test gases Designation d
i i s s
and by volume
group
c 3 3 3 3
MJ/kg MJ/kg
% MJ/m MJ/m MJ/m MJ/m
Gases of the third
family
Reference n-C H = 50 80,58 116,09 45,65 87,33 125,81 49,47 2,075
4 10
gas
Groups Incomplete G 30 i- C H = 50
4 10
B/ P combustion
and sooting
limit gas
Flame lift G 31 C H = 100 70,69 88,00 46,34 76,84 95,65 50,37 1,550
3 8
limit gas
and B Light back G 32 C H = 100 68,14 82,78 45,77 72,86 88,52 48,94 1,476
3 6
limit gas
Group P Reference G 31 C H = 100 70,69 88,00 46,34 76,84 95,65 50,37 1,550
3 8
gas,
Incomplete
combustion,
flame lift and
sooting limit
gas
Light back G 32 C H = 100 68,14 82,78 45,77 72,86 88,52 48,94 1,476
3 6
and sooting
limit gas
For gases used nationally or locally, see B.5.
For other groups, see B.5.
See also Annex A.

Limit gas used only for certain types of appliance, specified in the individual appliance standards (e.g. fully premixed

burners, forced draught burners, …).
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SIST EN 437:2021
EN 437:2021 (E)

Table 4 — Characteristics of the reference gases of the second family at 0 °C and 1 013,25 mbar

Composition
W H W H
Gas group Test gas Designation d
i i s s
by volume
3 3 3 3
%
MJ/m MJ/m MJ/m MJ/m
Group H Reference G 20 CH = 100 48,20 35,90 53,61 39,94 0,555
gas
Group L Reference G 25 CH = 86 39,45 30,87 43,88 34,34 0,613
gas, light
back limit
gas
N = 14
Group E Reference G 20 CH = 100 48,20 35,90 53,61 39,94 0,555
gas
5 Test pressures

The values of the test pressures, i.e. the static pressure to be applied at the gas inlet connection to the

appliance whilst in operation, are given in Tables 5 and 6.
NOTE The test conditions are specified in the individual appliance standards.
However:

— for the combustion test in still air with G 21 the appliance is first adjusted on G 20 to give an increase of

5 % in the nominal heat input where a gas pressure governor exists, and an increase of 7,5 % in the

absence of a governor. Gas G 21 is then substituted for G 20 without altering this adjustment;

— tests for ignition and crosslighting should be carried out at an inlet pressure of 0,7 times the normal

pressure (p ) using the reference gas(es) for the first and second families.
---------------------- Page: 14 ----------------------
SIST EN 437:2021
EN 437:2021(E)
Table 5 — Test pressures where no pressure couple exists
Appliance categories Test gas p p p
n min max
having as index
mbar mbar mbar
G 110 8 6 15
1 family 1a
G 112
G 20, G 21, 20 17 25
2 family
2H G 222, G 23
G 25, G 26, 25 20 30
2 family
2L G 27
G 20, G 21, 20 17 25
2 family
2E G 222, G 231
G 20, G 21, 20 17 30
G 222, G 231,
2 family
G 25, G 26,
G 27
G 25, G 26, 25 20 30
G 27
G 30, G 31, 25 35
G 32
3 family
3B/P G 30, G 31, 50 42,5 57,5
G 32
G 31, G 32 30 25 35
3 family, 3P
G 31, G 32 37 25 45
3 family
3P G 31, G 32 50 42,5 57,5
G 30, G 31, 29 20 35
3 family
G 32

For test pressures corresponding to gases distributed nationally or locally, refer to Table B.5.

Appliances of this category may be used, without adjustment, at the specified supply pressures

of 28 mbar to 30 mbar.

The tests with G 31 and G 32 are carried out at the normal pressure only (p = 29 mbar), these

test gases being more severe than any gas distributed. This condition covers the normal

variations in the gas supply.
See definition in 6.1.2.3.
---------------------- Page: 15 ----------------------
SIST EN 437:2021
EN 437:2021 (E)
Table 6 — Test pressures where a pressure couple exists
p p p
Appliance categories Test gas
n min max
having as index
mbar mbar mbar
G 20, G 21, G222 20 17 25
2 family: 2E+
a b
(20⇆25 couple) G 231 30
(25) 17
rd c
G 30 20 35
3 family: 3+ 29
(28–30⇆37 couple) G 31, G 32 37 25 45
G 30 50 42,5 57,5
3 family: 3+
(50⇆67 couple) G 31, G 32 67 50 80
G 30 112 60 140
3 family: 3+
(112⇆148 couple) G 31, G32 148 100 180

This pressure corresponds to the use of low Wobbe index gas but in principle no test is carried

out at this pressure.
See B.6.

Appliances of this category may be used without adjustment at the specified supply pressures of

28 mbar to 30 mbar.
6 Classification of appliances
6.1 Appliance categories
6.1.1 General

Appliances are classified into categories defined according to the gases and the pressures for which they are

designed.
The definition of the categories follows from 6.1.2, 6.1.3 and 6.1.4.

In each country, taking account of the local gas distribution conditions (gas composition and supply

pressures), only some of the categories defined in 6.1.2, 6.1.3 and 6.1.4 are marketed. In addition, some of

these categories are used only for certain types of appliances as specified in the individual appliance

standards.

The conditions concerning the marketing of these appliance categories in each country and the corresponding

supply pressures are given in Tables B.1, B.2 and B.3 (see also B.4 for the categories marketed locally and

nationally, corresponding to the gases and specific supply pressures given in Table B.5; B.6 gives the

particular conditions specific to certain countries).
NOTE See also Annex C - Guidelines for extension to other categories.
6.1.2 Category I
6.1.2.1 General

Appliances of category I are designed exclusively for the use of gases of a single family or of a single group.

6.1.2.2 Appliances designed for use on first family gases only

Category I : appliances using only gases of group a of the first family at the prescribed supply pressure (this

category is not used).
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6.1.2.3 Appliances designed for use on second family gases only

Category I : appliance using only gases of group H of the second family at the prescribed supply pressure.

Category I : appliances using only gases of group L of the second family at the prescribed supply pressure.

Category I : appliances using only gases of group E of the second family at the prescribed supply pressure.

Category I : appliances using only gases of group E of the second family, and operating with a pressure

2E+

couple without adjustment of the appliance. The appliance gas pressure regulating device, if it exists, is not

operative at pressures in between the two normal pressures of the pressure couple.

Category I : appliances using only second family gases at the prescribed supply pressure and that

automatically adapt to all gases of the second family.

Category I : appliances having a pressure regulator which can be manually adjusted in order to utilize each

of the following gas groups: H, E, L, K and LL (see also Table B.6).
family gases only
6.1.2.4 Appliances designed for use on 3

Category I : appliances capable of using the third family gases (propane and butane)

...

SLOVENSKI STANDARD
oSIST prEN 437:2020
01-julij-2020
Preskusni plini - Preskusni tlaki - Kategorije naprav
Test gases - Test pressures - Appliance categories
Prüfgase - Prüfdrücke - Gerätekategorien
Gaz d'essais - Pressions d'essais - Catégories d'appareils
Ta slovenski standard je istoveten z: prEN 437
ICS:
27.060.20 Plinski gorilniki Gas fuel burners
91.140.40 Sistemi za oskrbo s plinom Gas supply systems
oSIST prEN 437:2020 en,fr,de

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

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oSIST prEN 437:2020
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oSIST prEN 437:2020
DRAFT
EUROPEAN STANDARD
prEN 437
NORME EUROPÉENNE
EUROPÄISCHE NORM
July 2020
ICS 27.060.20; 91.140.40 Will supersede EN 437:2018
English Version
Test gases - Test pressures - Appliance categories

Gaz d'essais - Pressions d'essais - Catégories Prüfgase - Prüfdrücke - Gerätekategorien

d'appareils

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

CEN/TC 238.

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

© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 437:2020 E

worldwide for CEN national Members.
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oSIST prEN 437:2020
prEN 437:2020 (E)
Contents Page

European foreword ....................................................................................................................................................... 3

1 Scope .................................................................................................................................................................... 4

2 Normative references .................................................................................................................................... 4

3 Terms and definitions ................................................................................................................................... 4

4 Gases .................................................................................................................................................................... 7

4.1 Classification in gas families and groups ................................................................................................ 7

4.2 Test gases ........................................................................................................................................................... 8

5 Test pressures ............................................................................................................................................... 12

6 Classification of appliances ...................................................................................................................... 14

6.1 Appliance categories ................................................................................................................................... 14

6.1.1 General ............................................................................................................................................................. 14

6.1.2 Category I ........................................................................................................................................................ 14

6.1.3 Category II ....................................................................................................................................................... 15

6.1.4 Category III ..................................................................................................................................................... 16

6.2 Operations permitted for a change of gas or pressure, adjustment and regulating

devices .............................................................................................................................................................. 17

7 Choice of test gases and test pressures ................................................................................................ 17

8 Marking ............................................................................................................................................................ 18

Annex A (normative) Conditions for preparation of the test gases ........................................................ 19

Annex B (informative) National situations ...................................................................................................... 20

B.1 General ............................................................................................................................................................. 20

B.2 Categories listed in the body of the standard marketed in the different countries ............. 20

B.3 Appliance supply pressures corresponding to the categories given in B.1 and B.2 ............ 23

B.4 Special categories marketed nationally or locally ........................................................................... 27

B.4.1 General ............................................................................................................................................................. 27

B.4.2 Categories ....................................................................................................................................................... 33

B.5 Test gases and test pressures corresponding to the special categories given in B.4 .......... 40

B.6 Special conditions ........................................................................................................................................ 47

B.7 National and local gas distribution specifications relevant for defining appliance

categories given in B.4 ................................................................................................................................ 54

Annex C (informative) Guidelines for extension to other categories ..................................................... 55

Annex D (informative) Relationship between the distributed gases and the corresponding test

gases .................................................................................................................................................................. 56

Bibliography ................................................................................................................................................................. 57

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oSIST prEN 437:2020
prEN 437:2020(E)
European foreword

This document (prEN 437:2020) has been prepared by Technical Committee CEN/TC 238 “Test gases, test

pressures, appliance categories and gas appliance types”, the secretariat of which is held by AFNOR.

This document is currently submitted to the CEN Enquiry.
This document will supersede EN 437:2018.

EN 437 is intended to provide all the CEN Technical Committees preparing standards on gas appliances with

definitions for test gases, test pressures and categories of appliances for use by these committees within the

limits of the scope defined in Clause 1.

The document seeks to clarify the present situation with respect to test gases, test pressures and appliance

categories.

The concern for clarity has led to the elucidation of numerous categories and national situations or

conditions. The complexity of the document is likely to increase as new members join the Union.

This document can be considered as an important stage in the harmonization of test gases, test pressures and

appliance categories and the quality of information on gas usage in Europe.

In comparison with the previous version, this document incorporates updates of Table 6, Table 7, Table B.4

and some editorial changes.

Annex B gives national situations relating to gases, gas pressures and appliance categories that apply

nationally or locally. The information provided is included under the responsibility of the national

standardization bodies. The tables of Annex B give the available information. Therefore Annex B is

informative.
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1 Scope

This document specifies the test gases, test pressures and categories of appliances relative to the use of

gaseous fuels of the first, second and third families. It serves as a reference document in the specific standards

for appliances.

The document makes recommendations for the use of the gases and pressures to be applied for the tests of

appliances burning gaseous fuels.

NOTE Procedures for tests are given in the corresponding appliance standards. The test gases and the test

pressures specified in this standard are in principle intended to be used with all types of appliances. .

However, the use of some test gases and test pressures may not be appropriate in the following cases:

— appliances with nominal heat input greater than 300 kW;
— appliances constructed on site;
— appliances in which the final design is influenced by the user;

— appliances constructed for use with high supply pressures (notably direct use of the saturated vapour

pressure).

In these cases, the specific appliance standards may specify other test conditions in order to establish

compliance with their requirements.
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 ISO 3166-1:2014, Codes for the representation of names of countries and their subdivisions - Part 1: Country

codes (ISO 3166-1:2013)

EN ISO 6976:2016, Natural gas - Calculation of calorific values, density, relative density and Wobbe indices from

composition (ISO 6976:2016)
3 Terms and definitions
For the purposes of this document, the following terms and definitions 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
gas appliance
appliance burning gaseous fuels

Note 1 to entry For the purposes of this standard the term “gaseous fuels” means any fuel which is in a gaseous state

at a temperature of 15 °C under an absolute pressure of 1 bar
3.2
distributed gases
gaseous fuels used on the territory of the CEN members
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3.3
test gases

gases intended for the verification of the operational characteristics of gas appliances, they consist of

reference gases and limit gases
3.4
reference gases

test gases with which appliances operate under nominal conditions when they are supplied at the

corresponding normal pressure
3.5
limit gases

test gases representative of the extreme variations in the characteristics of the gases for which appliances

have been designed
3.6
test pressures

gas pressures used to verify the operational characteristics of gas appliances, consisting of normal and limit

pressures

Note 1 to entry The gas pressures used are expressed in millibars (mbar) 1 mbar = 10 Pa

3.7
normal pressure (p )

pressure under which the appliances operate in nominal conditions when they are supplied with the

corresponding reference gas
3.8
limit pressures
maximum pressure: p ; minimum pressure: p
max min

pressures representative of the extreme variations in the appliance supply conditions

3.9
pressure couple

combination of two distinct gas distribution pressures applied by reason of the significant difference existing

between the Wobbe indices within a single family or group in which
— the higher pressure corresponds only to gases of low Wobbe index;
— the lower pressure corresponds to gases of high Wobbe index.
Note 1 to entry The pressure couple is indicated by using the symbol (⇆)
3.10
reference conditions
these correspond to 15 °C, 1 013, 25 mbar, unless otherwise specified
3.11
relative density (d)

ratio of the masses of equal volumes of dry gas and dry air under the same conditions of temperature and

pressure: 15 °C or 0 °C and 1 013, 25 mbar
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3.12
calorific value

quantity of heat produced by the complete combustion, at a constant pressure equal to 1 013,25 mbar, of a

unit volume or mass of gas, the constituents of the combustible mixture being taken at reference conditions

and the products of combustion being brought back to the same conditions
A distinction is made between:

— the gross calorific value H : the water produced by combustion is assumed to be condensed;

— the net calorific value H : the water produced by combustion is assumed to be in the vapour state

Note 1 to entry The calorific value is expressed:

— either in megajoules per cubic metre (MJ/m ) of dry gas under the reference conditions;

— or in megajoules per kilogram (MJ/kg) of dry gas.
3.13
Wobbe index
gross Wobbe index W ; net Wobbe index W
s i

ratio of the calorific value of a gas per unit volume and the square root of its relative density under the same

reference conditions

Note 1 to entry The Wobbe indices are expressed in megajoules per cubic metre (MJ/m ) of dry gas under the

reference conditions.

Note 2 to entry The Wobbe index is said to be gross or net according to whether the calorific value used is the gross

or net calorific value.
3.14
heat input (Q)

quantity of energy used in unit time corresponding to the volumetric or mass flow rates, the calorific value

used being either the net or gross calorific value
Note 1 to entry The heat input is expressed in kilowatts (kW)
3.15
nominal heat input (Q )
value of the heat input declared by the manufacturer
3.16
mass flow rate (M)
mass of gas consumed by the appliance in unit time during continuous operation

Note 1 to entry The mass flow rate is expressed in kilograms per hour (kg/h) or grams per hour (g/h)

3.17
volume flow rate (V)
volume of gas consumed by the appliance in unit time during continuous operation

Note 1 to entry The volume flow rate is expressed in cubic metres per hour (m /h), litres per minute (l/min), cubic

decimetres per hour (dm3/h) or cubic decimetres per second (dm /s)
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3.18
gas family

group of gaseous fuels with similar burning behaviour linked together by a range of Wobbe indices (see

Table 1)
3.19
gas group
specified range of Wobbe index within that of the family concerned (see Table 1)

Note 1 to entry: this range is determined on the general principle that appliances using this gas group operate safely

when burning all gases within this range without adjustment

Note 2 to entry: Adjustment of the appliance may be permitted in accordance with the special national or local

conditions that apply in some countries (see B.4). For gases corresponding to national or local conditions, see Tables

B.5, B.6 and B.7
3.20
appliance category

means of identifying the gas families and/or gas groups that a gas appliance is designed to utilize safely and

to the desired performance level (see individual appliance standards)

Note 1 to entry: General appliance categories are described in 6.1. Special appliance categories marketed nationally

or locally are described in B.4
4 Gases
4.1 Classification in gas families and groups

Gases are classified into three families, each family may be divided into groups, (themselves being divided

into ranges, see Annex B), as a function of the Wobbe index, according to the values given in Table 1.

NOTE The classification given in Table 1 is used for the communication of the types of gas and corresponding

supply pressures of gaseous fuels used on their territory of Member States.
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Table 1 — Classification of gas families and groups as a function of the Wobbe indices, dry gas at

15 °C and 1 013,25 mbar
Gas families and groups Gross Wobbe index, dry gas at 15 °C and 1 013,25 mbar
MJ/m
Minimum Maximum
First family
— Group a 22,4 24,8
Second family 39,1 54,7
— Group H 45,7 54,7
— Group L 39,1 44,8
— Group E 40,9 54,7
Third family 72,9 87,3
— Group B/P 72,9 87,3
— Group P 72,9 76,8
— Group B 81,8 87,3
4.2 Test gases

The composition and principal characteristics of the different test gases corresponding to the gas families or

groups are given in Tables 2 and 3.

In particular cases specified in the individual appliance standards, gas G 24, whose characteristics are given

in Table 3, may be used but only at the normal test pressure.

The calorific values of the third family gases, expressed in mega joules per cubic metre in Table 2, may also

be expressed in mega joules per kilogram of dry gas, as shown in Table 3.

The values in Tables 2 and 3, measured and expressed at 15 °C, are derived from EN ISO 6976:2016.

The conditions for the preparation of the test gases are given in Annex A.

NOTE The characteristics for second family gases at reference conditions other than 15 °C for metering and 15 °C

for combustion can be calculated using the coefficients given in EN ISO 13443:2005, Annex A (normative). As an

example, the characteristics of the reference gases of the second family at 0 °C for metering and for combustion and

1 013,25 mbar (dry gas) are given in Table 4.
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Table 2 — Characteristics of the test gases for the first and second families, gas dry at 15 °C and

1 013,25 mbar
Gas Test gases Designation Composition W H W H d
i i s s
family by volume
and
Group
c 3 3 3 3
% MJ/m MJ/m MJ/m MJ/m
Gases of the first family
Group a Reference gas G 110 CH = 26
Incomplete H = 50 21,76 13,95 24,75 15,87 0,411
combustion,
N = 24
flame lift and
sooting limit gas
Light back limit G 112 CH = 17
gas
H = 59 19,48 11,81 22,36 13,56 0,367
N = 24
Gases of the second family
Group H Reference gas G 20 CH = 100 45,67 34,02 50,72 37,78 0,555
Incomplete G 21 CH = 87 49,60 41,01 54,69 45,28 0,684
combustion and
C H = 13
3 8
sooting limit gas
Light back limit G 222 CH = 77 42,87 28,53 47,87 31,86 0,443
gas
H = 23
Flame lift limit G 23 CH = 92,5 41,11 31,46 45,66 34,95 0,586
gas
N = 7,5
Over heating G 24 CH = 68 47,01 35,70 52,09 39,55 0,577
limit gas
C H = 12
3 8
H = 20
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Gas Test gases Designation Composition W H W H d
i i s s
family by volume
and
Group
c 3 3 3 3
% MJ/m MJ/m MJ/m MJ/m
Group L Reference gas G 25 CH = 86 37,38 29,25 41,52 32,49 0,612
light back limit
N = 14
gas
Incomplete G 26 CH = 80 40,52 33,36 44,83 36,91 0,678
combustion and
C H = 7
3 8
sooting limit gas
N = 13
Flame lift limit G 27 CH = 82 35,17 27,89 39,06 30,98 0,629
gas
N = 18
Group E Reference gas G 20 CH = 100 45,67 34,02 50,72 37,78 0,555
Incomplete G 21 CH = 87 49,60 41,01 54,69 45,28 0,684
combustion and
sooting limit gas
C H = 13
3 8
Light back limit G 222 CH = 77 42,87 28,53 47,87 31,86 0,443
gas
H = 23
Flame lift limit G 231 CH = 85 36,82 28,91 40,90 32,11 0,617
gas
N = 15
Over heating G 24 CH = 68 47,01 35,70 52,09 39,55 0,577
limit gas
C H = 12
3 8
H = 20
For gases used nationally or locally, see B.5.
For other groups, see B.5.
See also Annex A.

Limit gas used only for certain types of appliance, specified in the individual appliance standards (e.g. fully

premixed burners, forced draught burners, …).
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Table 3 — Characteristics of the test gases for the third family, gas dry at 15 °C and 1 013,25 mbar

Gas Test gases Designation Composition W H W H d
i i s s
family by volume
and
Group
c 3 3 MJ/kg 3 3 MJ/kg
% MJ/m MJ/m MJ/m MJ/m
Gases of the third
family
Reference n- 80,58 116,09 45,65 87,33 125,81 49,47 2,075
gas C H = 50
4 10
Groups Incomplete G 30 i-
B/ P combustion C H = 50
4 10
and sooting
limit gas
Flame lift G 31 C H = 100 70,69 88,00 46,34 76,84 95,65 50,37 1,550
3 8
limit gas
and B Light back G 32 C H = 100 68,14 82,78 45,77 72,86 88,52 48,94 1,476
3 6
limit gas
Group Reference G 31 C H = 100 70,69 88,00 46,34 76,84 95,65 50,37 1,550
3 8
P gas,
Incomplete
combustion,
flame lift
and sooting
limit gas
Light back G 32 C H = 100 68,14 82,78 45,77 72,86 88,52 48,94 1,476
3 6
and sooting
limit gas
For gases used nationally or locally, see B.5.
For other groups, see B.5.
See also Annex A.

Limit gas used only for certain types of appliance, specified in the individual appliance standards (e.g. fully premixed

burners, forced draught burners, …).
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Table 4 — Characteristics of the reference gases of the second family at 0 °C and 1 013,25 mbar

Gas group Test gas Designati Compositio W H W H
i i s s
on n by
volume
% 3 3 3 3 d
MJ/m MJ/m MJ/m MJ/m
Group H Reference G 20 CH = 100 48,20 35,90 53,61 39,94 0,555
gas
Group L Reference G 25 CH = 86 39,45 30,87 43,88 34,34 0,613
gas, light
back limit
gas
N = 14
Group E Reference G 20 CH = 100 48,20 35,90 53,61 39,94 0,555
gas
5 Test pressures

The values of the test pressures, i.e. the static pressure to be applied at the gas inlet connection to the

appliance whilst in operation, are given in Tables 5 and 6.
NOTE The test conditions are specified in the individual appliance standards.
However:

— for the combustion test in still air with G 21 the appliance is first adjusted on G 20 to give an increase of

5 % in the nominal heat input where a gas pressure governor exists, and an increase of 7,5 % in the

absence of a governor. Gas G 21 is then substituted for G 20 without altering this adjustment;

— tests for ignition and crosslighting should be carried out at an inlet pressure of 0,7 times the normal

pressure (p ) using the reference gas(es) for the first and second families.
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Table 5 — Test pressures where no pressure couple exists
Pressures in millibars
Appliance categories Test gas P p p
n min max
having as index
st G 110 8 6 15
1 family 1a
G 112
nd G 20, G 21, 20 17 25
2 family
2H G 222, G 23
nd G 25, G 26, 25 20 30
2 family
2L G 27
nd G 20, G 21, 20 17 25
2 family
2E G 222, G 231
G 20, G 21, 20 17 30
nd G 222, G 231,
2 family
G 25, G 26,
G 27
d G 25, G 26, 25 20 30
G 27
G 30, G 31, b 25 35
rd G 32
3 family
3B/P G 30, G 31, 50 42,5 57,5
G 32
rd G 31, G 32 30 25 35
3 family, 3P
rd G 31, G 32 37 25 45
3 family
3P G 31, G 32 50 42,5 57,5
rd G 30, G 31, 29 20 35
3 family
c G 32

For test pressures corresponding to gases distributed nationally or locally, refer to Table B.5.

Appliances of this category may be used, without adjustment, at the specified supply pressures

of 28 mbar to 30 mbar.

The tests with G 31 and G 32 are carried out at the normal pressure only (p = 29 mbar), these

test gases being more severe than any gas distributed. This condition covers the normal variations in

the gas supply.
See definition in 6.1.2.3.
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Table 6 — Test pressures where a pressure couple exists
Pressures in millibars
Appliance categories Test gas p P p
n min max
having as index
nd G 20, G 21, G222 20 17 25
2 family: 2E+
(20⇆25 couple) G 231 a b 30
(25) 17
rd G 30 c 20 35
3 family: 3+ 29
(28–30⇆37 couple) G 31, G 32 37 25 45
rd G 30 50 42,5 57,5
3 family: 3+
(50⇆67 couple) G 31, G 32 67 50 80
rd G 30 112 60 140
3 family: 3+
(112⇆148 couple) G 31, G32 148 100 180

This pressure corresponds to the use of low Wobbe index gas but in principle no test is carried

out at this pressure.
See B.6.

Appliances of this category may be used without adjustment at the specified supply pressures of

28 mbar to 30 mbar.
6 Classification of appliances
6.1 Appliance categories
6.1.1 General

Appliances are classified into categories defined according to the gases and the pressures for which they are

designed.
The definition of the categories follows from 6.1.2, 6.1.3 and 6.1.4.

In each country, taking account of the local gas distribution conditions (gas composition and supply

pressures), only some of the categories defined in 6.1.2, 6.1.3 and 6.1.4 are marketed. In addition, some of

these categories are used only for certain types of appliance as specified in the individual standards.

The conditions concerning the marketing of these appliance categories in each country and the corresponding

supply pressures are given in Tables B.1, B.2 and B.3 (see also B.4 for the categories marketed locally and

nationally, corresponding to the gases and specific supply pressures given in Table B.5; B.6 gives the

particular conditions specific to certain countries).
NOTE See also Annex C - Guidelines for extension to other categories.
6.1.2 Category I
6.1.2.1 General

Appliances of category I are designed exclusively for the use of gases of a single family or of a single group.

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6.1.2.2 Appliances designed for use on first family gases only

Category I : appliances using only gases of group a of the first family at the prescribed supply pressure (this

category is not used).
6.1.2.3 Appliances designed for use on second family gases only

Category I : appliance using only gases of group H of the second family at the prescribed supply pressure.

Category I : appliances using only gases of group L of the second family at the prescribed supply pressure.

Category I : appliances using only gases of group E of the second family at the prescribed supply pressure.

Category I : appliances using only gases of group E of the second family, and operating with a pressure

2E+

couple without adjustment on the appliance. The appliance gas pressure regulating device, if it exists, is not

operative at pressures in between the two normal pressures of the pressure couple.

Category I : appliances using only second family gases at the prescribed supply pressure and that

automatically adapt to all gases of the second family.

Category I : appliances having a pressure regulator which can be manually adjusted in order to utilize each

of the following gas groups: H, E, L, K and LL (see also Table B.6).
6.1.2.4 Appliances designed for use on 3 family gases only

Category I : appliances capable of using the third family gases (propane and butane) at the prescribed

3B/P
supply pressure.

Category I : appliances capable of using gases of the third family (propane and butane) and operating with

a pressure couple without adjustment of the appliance. However, for certain types of appliance specified in

the particular standards, adjustment of the primary combustion air may be permitted when changing from

propane to butane and vice versa. No gas pressure regulating device is permitted on the appliance.

Category I : appliances using only gases of group P of the third family (propane) at the prescribed supply

pressure.
Category I : appliances using only
...

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