FprEN 125

SLOVENSKI STANDARD
oSIST prEN 125:2020
01-maj-2020
Naprave za nadzor plamena pri plinskih aparatih - Termoelektrična varovala

Flame supervision devices for gas burning appliances - Thermoelectric flame supervision

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

Dispositifs de surveillance de flamme pour appareils à Flammenüberwachungseinrichtungen für Gasgeräte -

gaz - Dispositifs thermoélectriques de surveillance de Thermoelektrische Zündsicherungen

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

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

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

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

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

© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 125:2020 E

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

1 Scope .................................................................................................................................................................... 5

2 Normative references .................................................................................................................................... 5

3 Terms and definitions ................................................................................................................................... 5

4 Classification ..................................................................................................................................................... 6

4.1 Classes of control ............................................................................................................................................. 6

4.2 Groups of control ............................................................................................................................................. 6

4.3 Classes of control functions ......................................................................................................................... 6

4.4 Types of DC supplied controls .................................................................................................................... 6

5 Test conditions and uncertainty of measurements ............................................................................ 6

6 Design and Construction .............................................................................................................................. 6

6.1 General ................................................................................................................................................................ 6

6.2 Mechanical parts of the control ................................................................................................................. 6

6.3 Materials ............................................................................................................................................................. 7

6.4 Gas connections ............................................................................................................................................... 7

6.5 Electronic parts of the control .................................................................................................................... 8

6.6 Protection against internal faults for the purpose of functional safety ...................................... 8

7 Performance ..................................................................................................................................................... 8

7.1 General ................................................................................................................................................................ 8

7.2 Leak-tightness .................................................................................................................................................. 9

7.3 Torsion and bending ................................................................................................................................... 10

7.4 Rated flow rate .............................................................................................................................................. 10

7.5 Durability ........................................................................................................................................................ 10

7.6 Performance tests for electronic controls .......................................................................................... 10

7.7 Long-term performance for electronic controls ............................................................................... 11

7.8 Data exchange ............................................................................................................................................... 11

7.101 Operating torque and force ...................................................................................................................... 11

7.102 Interlocks ........................................................................................................................................................ 12

7.103 Closing current .............................................................................................................................................. 12

7.104 Sealing force ................................................................................................................................................... 13

7.105 Endurance ....................................................................................................................................................... 13

8 EMC/Electrical requirements .................................................................................................................. 14

9 Electromagnetic compatibility (EMC) ................................................................................................... 14

10 Marking, instructions ................................................................................................................................. 15

10.1 Marking ............................................................................................................................................................ 15

10.2 Instructions .................................................................................................................................................... 15

10.3 Warning notice .............................................................................................................................................. 15

Annex A (informative) Abbreviations and Symbols .................................................................................... 16

Annex B (informative) Leak-tightness test for gas controls − volumetric method .......................... 17

Annex C (informative) Leak-tightness test − pressure loss method ...................................................... 18

Annex D (normative) Calculation of pressure loss into leakage rate .................................................... 19

Annex E (normative) Electrical/electronic component fault modes ..................................................... 20

Annex F (normative) Additional requirements for safety accessories and pressure

accessories as defined in EU Directive 2014/68/EU........................................................................ 21

Annex G (normative) Materials for pressurized parts ................................................................................ 22

Annex H (informative) Additional materials for pressurized parts ....................................................... 23

Annex I (normative) Requirements for controls used in DC supplied burners and burning

gaseous or liquid fuels appliances .......................................................................................................... 24

Annex J (normative) Method for the determination of the Safety Integrity Level (SIL) .................. 25

Annex K (normative) Method for the determination of a Performance Level (PL) .......................... 26

Performance Level (PL) .............................................................................................................................. 27

Annex M (normative) Reset functions ............................................................................................................... 28

Annex N (informative) Guidance document on environmental aspects ............................................... 29

Annex O (normative) Seals of elastomers, cork and synthetic fibre mixtures ................................... 30

Annex AA (informative) Types of flame supervision devices .................................................................... 31

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

Requirements of Regulation (EU) 2016/426 aimed to be covered ............................................ 33

Annex ZB (informative) Relationship between this European Standard and the Essential

Requirements of EU Directive 2014/68/EU........................................................................................ 37

Bibliography ................................................................................................................................................................. 38

This document (prEN 125:2020) has been prepared by Technical Committee CEN/TC 58 “Safety and

control devices for burners and appliances burning gaseous or liquid fuels”, the secretariat of which is

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

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

This document is intended to be used in conjunction with EN 13611:2019. This document refers to

clauses of EN 13611:2019 or adapts clauses by stating “with the following modification”, “with the

following addition”, “is replaced by the following” or “is not applicable” in the corresponding clause.

This document adds clauses or subclauses to the structure of EN 13611:2019 which are particular to

this standard. It should be noted that these clauses and subclauses are not indicated as an addition.

Subclauses which are additional to those in EN 13611:2019 are numbered starting from 101. Additional

The following significant technical changes compared to the previous edition have been incorporated in

This document specifies the safety, construction and performance requirements for thermoelectric

flame supervision devices, energized by a thermocouple intended for use with gas burners, gas

This document is applicable to controls with declared maximum inlet pressures up to and including

500 kPa (5 bar) of nominal connection sizes up to and including DN 50 for use with one or more fuel

b) controls which use auxiliary energy (e.g. electrical energy supplied externally).

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 13611:2019, Safety and control devices for burners and appliances burning gaseous and/or liquid

For the purposes of this document, the terms and definitions given in EN 13611:2019 and the following

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

thermoelectric flame sensing element that responds to the temperature of the supervised flame, and in

control which, in response to the e.m.f. produced by the thermocouple, maintains the gas way to the

main burner or the main burner and the pilot burner open and which shuts off the gas way to the main

part which prevents the igniter from operating as long as the main gas way is open

mechanism which prevents the re-opening of the gas way to the main burner or to the main burner and

the pilot burner until the armature plate has separated from the magnetic element

force acting on the closure member when the closure member is in the closed position, independent of

Controls shall be classified A, B or C according to the number of operations as tested in 7.105.2.2.

Controls shall shut off the gas way to the burner automatically with at least the sealing force specified in

7.104 in case of failure in the thermoelectric current. Controls shall also be designed so that during

ignition either the gas way to the main burner is open, if there is no pilot burner, or the gas way to the

Strainers fitted to controls of DN 25 and above shall be accessible for cleaning or replacement without

Controls shall be leak-tight in accordance with the leakage rates given in Table 2.

Pressurize the inlet and outlet(s) of the control to the test pressures given in 7.2.2.2.

Before the test, closure parts which may be dismantled in accordance with 6.2.9 shall be dismantled and

reassembled five times to the manufacturer’s instructions and the leakage rate for each of the

a) The control shall be operated such that all closure members in the control are in the open position.

Any suitable electrical source may be used during the test. The inlet and outlet(s) of the control

b) The test of a) shall then be carried out with the electrical source removed so that the main and pilot

c) The test of a) shall then be repeated with any spindle moved during ignition and held in the ignition

Test in the closed position the leakage of the de-energized control in the direction of gas flow, at the test

pressures given in 7.2.2.1 and measure the leakage rate. If there is more than one closure member in

the control, the test shall be repeated with each closure member in turn in the closed position, all the

For controls equipped with a pilot burner outlet, this outlet shall be blocked. Test in the ignition

position the leakage of the de-energized control in the direction of gas flow at the test pressures given

The flow rate when measured according to 7.7 shall be between 0,95 times and 1,40 times the rated

If applicable the torque required to operate the control shall not exceed the values given in Table 3.

If the manufacturer supplies a knob together with the control, the operating torque shall not exceed

The force or pressure required to operate a push-button directly by hand shall not exceed 30 N for

nominal size of controls up to and including DN 10, and 45 N for nominal size of controls exceeding

The operating torque is measured with a suitable torque meter having an accuracy within ±10 % of the

maximum torque specified in Table 3 the relevant size of control to check for compliance with 7.101.1.

Carry out the opening and closing movement with a constant angular velocity of approximately

The operating force is measured with a suitable dynamo meter having an accuracy within ±10 % of the

If present, an ignition interlock shall prevent ignition as long as the closure member to the main burner

If present, a re-start interlock shall prevent the re-opening of the closure member controlling the main

burner or the main burner and the pilot burner until the armature plate has separated from the

Using ignition interlock, verify that ignition can only take place when the pilot gas way is open and the

closure member of the main gas way is closed. Thereafter, with the closure member of the main gas way

opened, it shall not be possible to operate the ignition device under all conditions.

To check a re-start interlock, energize the control with suitable electrical means and bring the control in

the normal operating position with closure member opened. Verify under these conditions that a re-

start attempt is not possible as long as the closure member is in the open position.

The initial closing current shall not exceed 200 mA and shall not be less than 40 mA unless otherwise

If the initial closing current is less than 100 mA, the closing current determined after the endurance test

If the initial closing current is 100 mA or greater, the closing current determined after the endurance

Connect a DC source (voltage approximately 2 V) with a variable resistor in series to the control to

simulate a thermocouple. If mains voltage is used rather than a battery, the direct current shall be

a) in the ignition position of the control the closure member of the control is held open by pressure or

torque on the push-button or knob as applicable (the armature plate being held in contact with the

b) excite the magnetic element by a current which is uniformly and continuously increased at a rate

less than 30 mA/s until it is approximately three times the maximum closing current declared by

c) release the push-button or knob with the control left in the fully open position, the armature plate

d) increase the current at any rate up to 1 500 mA, and sustain the current for at least 60 s;

e) reduce the current at a constant rate down to approximately 300 % of the maximum closing current

f) reduce the current further at a constant rate not exceeding 10 mA/s until the control closes (the

h) repeat the sequence ten times and from the values measured obtain the mean, which shall be taken

In the closed position the control shall have a minimum sealing force of 1 kPa (10 mbar) over the

closure member orifice area. The internal leak-tightness of the control according to the test method in

Alternatively, for controls with a maximum inlet pressure up to and including 10 kPa (100 mbar) and

When the closure member closes in the opposite direction to the gas flow, the sealing force shall be at

least 15 kPa (150 mbar) in excess of the maximum inlet pressure, and the internal leak-tightness of the

Connect an air supply through a flow meter to the outlet of the control such that the air pressure

Pressurize the control with an increasing rate less than 100 Pa/s (1 mbar/s) to a pressure of 1 kPa