EN 16475-4:2020

SLOVENSKI STANDARD
01-junij-2020
Dimovodne naprave - Oprema - 4. del: Dimovodne lopute - Zahteve in preskusne
metode
Chimneys - Accessories - Part 4: Flue dampers - Requirements and test methods
Abgasanlagen - Zubehörteile - Teil 4: Abgasklappen - Anforderungen und Prüfverfahren
Conduits de fumée - Accessoires - Partie 4: Clapets de gaz de fumées - Exigences et
méthodes d'essai
Ta slovenski standard je istoveten z: EN 16475-4:2020
ICS:
91.060.40 Dimniki, jaški, kanali Chimneys, shafts, ducts
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 16475-4
EUROPEAN STANDARD
NORME EUROPÉENNE
April 2020
EUROPÄISCHE NORM
ICS 91.060.40
English Version
Chimneys - Accessories - Part 4: Flue dampers -
Requirements and test methods
Conduits de fumée - Accessoires - Partie 4 : Clapets de Abgasanlagen - Zubehörteile - Teil 4: Abgasklappen -
fumées - Exigences et méthodes d'essai Anforderungen und Prüfverfahren
This European Standard was approved by CEN on 24 February 2020.

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
© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 16475-4:2020 E
worldwide for CEN national Members.

Contents Page
European foreword . 5
Introduction . 6
1 Scope . 7
2 Normative references . 8
3 Terms and definitions . 8
4 Product characteristics . 9
4.1 General . 9
4.1.1 Introduction . 9
4.1.2 Temperature classes . 9
4.1.3 Pressure classes . 9
4.1.4 Condensate resistance classes . 9
4.1.5 Corrosion resistance classes . 9
4.1.6 Sootfire resistance classes . 9
4.1.7 Distance to combustible material . 9
4.1.8 Flue damper type . 9
4.2 Safety in the case of fire . 10
4.2.1 Reaction to fire . 10
4.2.2 Fire resistance internal to external . 11
4.3 Hygiene, health and environment . 11
4.3.1 External gas tightness . 11
4.3.2 Internal gas tightness . 11
4.3.3 Flow resistance . 12
4.3.4 Thermal resistance . 12
4.3.5 Thermal shock resistance . 12
4.3.6 Impact resistance of the flue damper . 12
4.3.7 Accidental human contact . 12
4.4 Durability . 13
4.4.1 Condensate resistance . 13
4.4.2 Corrosion resistance . 13
4.4.3 Freedom of movement of the flue damper . 13
5 Testing, assessment and sampling methods . 14
5.1 Declaration for type test . 14
5.2 Mechanical resistance . 14
5.2.1 Free movement/durability test . 14
5.2.2 Impact resistance test . 15
5.3 Thermal performance tests . 16
5.3.1 General . 16
5.3.2 Test assembly . 16
5.3.3 Test procedure . 18
5.3.4 Test Results . 19
5.4 Gas tightness . 19
5.4.1 External gas tightness of the housing for all types of flue dampers . 19
5.4.2 Internal gas tightness of the flue damper flap for flue damper types 1 and 2 . 20
5.5 Condensate resistance test . 22
5.5.1 Test assembly . 22
5.5.2 Test procedure . 23
5.5.3 Test results . 23
5.6 Flow resistance of the flue damper . 24
5.6.1 Test assembly . 24
5.6.2 Test procedure . 24
5.6.3 Test results. 25
5.7 Test sequence . 25
6 Assessment and verification of constancy of performance — AVCP . 26
6.1 General . 26
6.2 Type testing . 26
6.2.1 General . 26
6.2.2 Test samples, testing and compliance criteria . 27
6.2.3 Test reports . 27
6.3 Factory production control (FPC) . 28
6.3.1 General . 28
6.3.2 Provisions . 28
6.3.3 Product specific provisions . 30
6.3.4 Initial inspection of factory and of FPC . 31
6.3.5 Continuous surveillance of FPC . 31
6.3.6 Procedure for modifications . 31
6.3.7 One-off products, pre-production products (e.g. prototypes) and products produced
in very low quantity . 32
7 Product classification and designation . 32
7.1 Classification . 32
7.2 Designation . 32
8 Marking, labelling and instruction . 33
8.1 Flue damper . 33
8.2 Product information . 33
8.2.1 Manufacturer's instructions . 33
8.2.2 Minimum information to be included in the manufacturer's instructions . 34
Annex A (normative) Sampling for factory production control . 35
A.1 Sampling plans. 35
A.1.1 General . 35
A.1.2 Acceptable quality level (AQL). 35
A.1.3 Normal, tightened or reduced inspection . 35
A.1.4 Single, double, multiple or sequential sampling . 35
A.1.5 Batch quantity . 35
A.2 Inspection levels and procedures . 35
A.2.1 Incoming material . 35
A.2.2 In-process inspection . 36
A.2.3 Finished goods checks . 36
A.3 Electrical inspection . 36
Annex B (informative) Recommended check and test sequence . 37
Annex C (informative) Additional information for the use of a flue damper type 2 and 4 . 39
C.1 Boilers with forced draught burners . 39
C.2 Boilers with burners with fan without air purging . 39
C.3 Boilers with burners with fan with post-purge period . 39
C.4 Gas boilers with burners without fan . 39
C.5 Closing time of the flue damper flap . 39
C.6 Malfunction of the flue damper . 39
Annex D (informative) Examples of different types of flue dampers . 40
Bibliography . 42

European foreword
This document (EN 16475-4:2020) has been prepared by Technical Committee CEN/TC 166 “Chimneys”,
the secretariat of which is held by ASI.
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 2020, and conflicting national standards shall
be withdrawn at the latest by January 2022.
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 forms a part of the series of standards EN 16475, Chimneys – Accessories, comprising the
following parts:
— Part 1: Silencers — Requirements and test methods;
— Part 2: Chimney fans — Requirements and test methods;
— Part 3: Draught regulators, standstill opening devices and combined secondary air devices —
Requirements and test methods;
— Part 4: Flue dampers — Requirements and test methods (this part);
— Part 6: Access components — Requirements and test methods;
— Part 7: Rain caps — Requirements and test methods.
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.
Introduction
The main purpose of flue dampers is to close or partially close a flue.
Flue dampers can be manually adjusted, sited in connecting flue pipes or chimneys, in order to reduce
the burning rate (solid fuel stoves/fireplaces) or to work as a shut-off slide preventing back flow of soot
during cleaning of the chimney, or mechanically driven for reducing/closing the flue, in order to reduce
the stand-by losses or to prevent the backflow of the flue gas e.g. in case of multi-served chimneys.
1 Scope
This document specifies the characteristics and test methods for flue dampers that are used as
components, carrying flue gas, in order to limit the flow in a chimney or to prevent back flow of soot
during cleaning of the chimney or to prevent the backflow of the flue gas e.g. in case of multi-served
chimneys.
This document covers only flue dampers incorporated in a housing and installed inside a building.
This document covers only flue dampers with sealings made of elastomeric materials for temperature
classes up to T 200 and corrosion class 1 or 2 in accordance with EN 14241-1 or sealing materials for dry
applications with a fire reaction class A1 in accordance with EN 13501-1.
This document covers only flue dampers with motor drive, casing and flue damper plate which are
interlocked in such a way that they can only be separated by using tools.
This document covers only mechanical flue dampers where any motor is in accordance with
EN 60730-2-14 and the cover for electrical components of the flue damper fulfils minimum protection
class IP40 according to EN 60529.
This document covers only flue dampers which are designed and installed to ensure that incorrect
information about the position of the flue damper flap are absolutely impossible, which are only installed
on components that are interlocked to the casing, which are only activated by components that are
interlocked to the flue damper flap and where it is ensured that the limit switch opens or the flue damper
flap moves to the open position if one of these interlocks fails. This safety target may also be achieved
with an equally suitable method (e.g. bracing or welding).
This document covers only flue dampers for biomass boilers ≥ 1 000 kW and industrial applications with
limit switches in accordance with EN 61058-1 or EN 50156-1.
This document covers only flue dampers where it is possible to identify the position of the flue damper
flap.
This document covers only totally closed, manually driven flue dampers (type 1) which have a facility to
adjust the position of the flue damper flap.
This document covers only totally closed, mechanically driven flue dampers (type 2) with only the
positions “fully opened” and “fully closed” and where it is not possible to fix the flap in the non-closed
position during the flue damper flap stays in closed position while the appliance is not working.
NOTE This applies only to multi-appliance installations with positive pressure conditions.
This document covers only partially closed flue dampers (type 3 to 5) where it is possible to adjust the
position of the flue damper flap and where it is ensured that the flue damper flap does not change position
by itself.
Flue dampers which are integral parts of system chimney products or other chimney components, e.g.
flue liners, connecting flue pipes, are not covered by this document.
This document also specifies the provisions for marking, manufacturers’ instruction, product
information, Assessment and Verification of Constancy of Performance (AVCP).
This document does not specify issues for electrical parts.
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 1443:2019, Chimneys — General requirements
EN 1561, Founding — Grey cast irons
EN 1563, Founding — Spheroidal graphite cast irons
EN 1856-1, Chimneys — Requirements for metal chimneys — Part 1: System chimney products
EN 1856-2:2009, Chimneys — Requirements for metal chimneys — Part 2: Metal flue liners and connecting
flue pipes
EN 13384-1, Chimneys — Thermal and fluid dynamic calculation methods — Part 1: Chimneys serving one
heating appliance
EN 13501-1, Fire classification of construction products and building elements — Part 1: Classification
using data from reaction to fire tests
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 1443, EN 1856-1 and EN 1856-2
and the following apply.
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp/ui
3.1
flue damper
device used to close or partially close the flue, comprising a rotating or sliding flue damper flap, including
fastening elements, in a flue damper housing that may be a section of connecting flue pipe or a section of
chimney (single or multi wall)
Note 1 to entry: Examples given in Annex D.
3.2
shut-off slide
flue damper type 1
flue damper which is intended to prevent the escape of dust out of the chimney during sweeping the
chimney
3.3
internal leakage rate
leakage rate inside the flue caused by the closed flap
3.4
external leakage rate
leakage rate from the inside of the component to the outside atmosphere
Note 1 to entry: Corresponds to the leakage rate of EN 1443:2019, Table 3.
4 Product characteristics
4.1 General
4.1.1 Introduction
In order to identify the characteristics of the flue damper the following product properties shall be
declared:
4.1.2 Temperature classes
The temperature class shall be declared in accordance with EN 1443:2019, Table 1.
4.1.3 Pressure classes
The pressure class shall be in accordance with EN 1443:2019, Table 3.
4.1.4 Condensate resistance classes
The condensate resistance class shall be in accordance with EN 1443:2019, 4.2.3.
4.1.5 Corrosion resistance classes
Corrosion resistance classes shall be in accordance with EN 1443:2019, Table 4.
4.1.6 Sootfire resistance classes
Sootfire resistance class shall be in accordance with EN 1443:2019, 4.2.5.
4.1.7 Distance to combustible material
The minimum allowed distance of the outer wall of the flue damper to walls and floors comprising
combustible material shall be expressed as “xx”, where “xx” is the value in whole millimetres, followed
with a letter “a” to “l” in accordance with EN 1443:2019, 4.2.6.
4.1.8 Flue damper type
The flue damper type shall be in accordance with Table 1.
Table 1 — Flue damper types
Flue Type description Condensate Pressure class Field of application
damper resistance class
type
D W N P/M/H
Totally closed manually Solid fuel manually
1 X — X —
driven fed without fan
All applications
Totally closed except solid fuel
2 X X X X
mechanically driven manually fed
without fan
Partially closed
Solid fuel manually
3 adjustable manually X — X —
fed without fan
a
driven
All applications
Partially closed
except solid fuel
4 adjustable X X X X
manually fed
mechanically driven
without fan
All applications
Partially closed except solid fuel
5 X X X X
fixed manually driven manually fed
without fan
a
opening according to national regulations or manufacturer's instructions or other standards (e.g.
EN 16510-1)
NOTE 'X' means 'applies to this flue damper type'.
4.2 Safety in the case of fire
4.2.1 Reaction to fire
The reaction to fire indicates the degree of contribution of the material to the behaviour of the
construction product in the event of fire. When tested in accordance to the test methods given in
EN 13501-1, relevant for the claimed class, the test results are expressed as a class according to
EN 13501-1.
Whether products covered by this document are made from one or more of the materials that have been
considered, under established conditions, as belonging to the category “No contribution to fire” because
of their low level of combustibility, the reaction to fire class A1 applies to these products without the need
of carrying out reaction to fire tests.
4.2.2 Fire resistance internal to external
Fire resistance internal to external is the capability of the flue damper to prevent a fire at adjacent
combustible materials caused by the chimney operation under:
— normal operating condition for the declared temperature class (see 4.1.2) and pressure class (see
4.1.3), and
— sootfire condition for products declared sootfire-resistant (G) or sootfire safe (As) (see 4.1.6),
taking into account the minimum allowed distance to combustible material (xx) in relation to the test
assembly corresponding to the walls and floors of a variety of building types and the thermal resistance
of their structure (see 4.1.7).
When tested according to the test method described in 5.3.3.2:
— the external gas tightness shall comply with 4.3.1 before and after the test;
— the maximum temperature of adjacent combustible materials shall not exceed 85 °C when related to
an ambient temperature of 20 °C at the distance declared by the manufacturer when tested at the
declared temperature class.
When tested according to the test method described in 5.3.3.3:
— the external gas tightness shall comply with 4.3.1 before and after the test;
— the maximum temperature of adjacent combustible materials shall not exceed 100 °C when related
to an ambient temperature of 20 °C at the distance declared by the manufacturer.
4.3 Hygiene, health and environment
4.3.1 External gas tightness
The external gas tightness is the capability of the flue damper to limit the leakage rate to the room where
flue damper is located appropriate to the designated pressure class (see 4.1.3).
When tested in accordance with the test method described in 5.4.1 the leakage rate in litres/seconds per
square meter of the inner flue surface area of the flue damper before and after any test shall not exceed
the values given in EN 1443:2019, Table 3. The inner flue surface area is calculated with the nominal
diameter of the flue damper. If the joint is a part of elements of the flue damper, the tests are made with
joints.
4.3.2 Internal gas tightness
The internal gas tightness is the capability of the flue damper to limit the leakage rate inside the flue
damper from one side of the flap to the other side.
When flue damper type 1 or 2 tested in accordance with the test method described in 5.4.2 both before
and after the thermal performance tests the internal leakage rate under the specific test pressure shall
not exceed the maximum leakage rate in Table 3.
For flue damper type 2 the leakage rate can be determined according to EN 15502-2-1 at a test pressure
of 100 Pa where the maximum leakage rate is 0,2 m /h for all diameters as additional information.
4.3.3 Flow resistance
The flow resistances due to friction of the flue and due to a directional and/or cross sectional and/or
mass flow change in the flue are the basis for the calculation of the pressure loss in the flue.
The coefficient of flow resistance (ζ) of the mechanically actuated flue damper shall be determined
according to the test method described in 5.6.
Characteristics are to be provided as mean value of roughness for the material of the flue or as coefficient
of flow resistance in accordance with EN 13384-1.
4.3.4 Thermal resistance
The thermal resistance of the chimney is the basis for the thermal and fluid dynamic calculation.
When tested in accordance to EN 1443:2019, 4.3.3, the thermal resistance shall be expressed as levels in
2.
m K/W.
4.3.5 Thermal shock resistance
The thermal shock resistance is the capability of the product to withstand the thermal load under:
— normal operating condition for the declared temperature class (see 4.1.2) and pressure class (see
4.1.3), and
— sootfire condition for products declared sootfire-resistant (G) or sootfire safe (As) (see 4.1.6).
When tested according to the test method described:
— in 5.3.3.2, and
— in 5.3.3.3 for products declared sootfire-resistant or sootfire safe,
the external gas tightness shall comply with 4.3.1 before and after the test.
4.3.6 Impact resistance of the flue damper
When tested according to 5.2.2 the flue damper shall also be able to be opened and closed freely before
and after the thermal tests and the external gas tightness shall comply with 4.3.1.
4.3.7 Accidental human contact
Where accidental human contact is possible, burnings shall be prevented.
When tested in accordance with the test method described in the appropriate clauses of EN 13216-1 the
surface temperature of the flue damper shall not exceed the values in EN 1443:2019, Table 10, or where
accidental human contact is possible, it shall be specified that the chimney shall be protected from
touching.
When the flue damper has a facility to adjust the position of the flue damper flap, e.g. handle, during
operation and where accidental human contact is possible a tool, e.g. glove, shall be used to move the
adjusting facility.
4.4 Durability
4.4.1 Condensate resistance
The condensate resistance is the capability of the product to withstand condensate exposure.
When flue dampers with the declared condensate resistance class (see 4.1.4) W are tested according to
the test method described in 5.5:
— no condensate shall appear on the outer surface of the mechanical flue damper device while the
damper is alternately opening and closing,
— for flue dampers situated in an insulated housing the increase of mass shall not be more than 1 % of
insulation material.
4.4.2 Corrosion resistance
The corrosion resistance is the capability of the product to withstand corrosion exposure.
For flue dampers, this is fulfilled if, depending on the declared condensate resistance class (see 4.1.4) and
the declared corrosion resistance class (see 4.1.5), the materials and minimum thicknesses of both the
flaps and the housings are in accordance with Table 2.
For materials and/or thicknesses not in accordance with Table 2 the durability against corrosion can be
verified by a corrosion test according to EN 1856-1.
Table 2 — Materials for flue damper flaps and housings
Corrosion resistance classes Dry (D) Wet (W)
1 A; B; C; D; E; F; G B; C; D; E
2 A; B; C; F; G C
3 A; B; C; F; G —
where:
A:cast iron, materials according to EN 1561 or EN 1563. - Minimum thickness 4 mm.
B: stainless steel, minimum material number according to EN 10088 of 1.4301 – Minimum thickness 0,8 mm.
C: stainless steel, minimum material number according to EN 10088 of 1.4404, 1.4571 or 1.4539 – Minimum
thickness 0,8 mm.
D: aluminium according to EN 1856-1 – Minimum thickness 1,5 mm.
E: plastic material grades which proved sufficient resistance in a test according to EN 14471 (use for conditions
as designated according to EN 14471).
F: Aluminium coated steel according to EN 10346 (see EN 1856-2). – Minimum Thickness 0,8 mm.
a
G: Black Steel according to EN 10025, S235 JRG 2 – Minimum thickness 1,5 mm.
a
Equivalent for material No. 1.0038 = 1.0330 (material grade DC01).
4.4.3 Freedom of movement of the flue damper
When tested according to 5.2.1.2 the flue damper types 1, 3 and 5 shall be able to move freely when
opened and closed minimum 100 times before and minimum 100 times after the thermal tests, and meet
4.3.1.
When tested according to 5.2.1.3 the flue damper types 2 and 4 shall be able to move freely when opened
and closed and shall comply with 4.3.1 before and after the test.
5 Testing, assessment and sampling methods
5.1 Declaration for type test
The relevant information in 8.1 and 8.2 shall be provided and additionally the following information:
a) drawings including declared nominal dimensions,
b) materials and minimum thicknesses of the materials,
c) method of fixing.
5.2 Mechanical resistance
5.2.1 Free movement/durability test
5.2.1.1 Test assembly for all flue damper types
Mount the flue damper on the test assembly of 5.4 according to the manufacturer’s instructions.
5.2.1.2 Test procedure for flue dampers types 1, 3 and 5 (manually driven)
Subject the flue damper to the external gas tightness test of 5.4.1.
For flue damper type 1 which can be fully closed undertake the internal gas tightness test of 5.4.2.
Move the flue damper flap of types 1, 3 or 5 (manually driven) to the open and closed position 100 times
and record whether the flue damper flap moves freely.
Subject the flue damper to the external gas tightness test of 5.4.1.
For flue damper type 1 which can be fully closed undertake the internal gas tightness test of 5.4.2.
Subject the flue damper to the thermal performance test of 5.3 appropriate to the flue damper
designation.
Move the flue damper flap to the open and closed position 100 times, record whether the flue damper
flap moves freely.
Subject the flue damper to the external gas tightness test of 5.4.1.
For flue damper type 1 which can be fully closed undertake the internal gas tightness test of 5.4.2.
5.2.1.3 Test procedure for flue dampers types 2 and 4 (mechanically driven)
Subject the flue damper to the internal and external gas tightness test of 5.4 both before and after the
minimum 50 000 switching cycles.
The flue damper is opened and closed continuously, using a time switch, independently from the heating,
whereby the respective closed position shall be at least 10 s. Initially, at least 2 500 switching operations
shall be carried out at nominal working temperature. Subsequently, 45 000 switching operations shall
take place at ambient temperature. After this, another 2 500 switching operations shall take place at
nominal working temperature.
Generate hot gas at the nominal working temperature according to 5.3 for a test assembly according to
Figure 1. The two flue dampers have to open and close alternatingly driven by a control or time switch.
Key
1 test sample flue damper
2 bypass flue damper
3 thermocouple for flue gas temperature
4 hot gas generator
D nominal diameter of the flue of the test sample
Figure 1 — Example of thermal free movement/durability test
5.2.1.4 Test Results
Record if the flue damper moves freely, and the internal and external leakage from the gas tightness tests
before and after the free movement/durability test.
5.2.2 Impact resistance test
5.2.2.1 Test assembly
Construct a test assembly according to Figure 2 with the flue damper installed according to the
manufacturer’s instructions.
Insert a device to load the flue damper without tilting, e.g. two disks connected by a rod or a cylinder with
a flat base, having a cross section > 80 % of the flue damper housing size.
Load the platform for a flue damper plate made of metal with a load F = 100 ( N for a time of at least
%)
+5
10 s.
Load the platform for a flue damper plate made of plastic/combined non-metallic materials with a load
F = 30 ( %) N for a time of at least 3 s.
+5
Key
1 flue damper flap (opened)
2 flue damper housing
3 loading device
F load
Figure 2 — Test assembly for impact resistance test
5.2.2.2 Test procedure
Test the flue damper type 1 in closed position. All other flue damper types shall be tested in open position.
0 0
Load the platform with 30 ( %) N or 100 ( %) N.
+5 +5
Subject the flue damper to the gas tightness test of 5.4.
Check if the free movement of the flue damper is still possible.
5.2.2.3 Test results
Record if the flue damper moves freely, and the internal and external leakage from the gas tightness test
before and after the impact resistance test.
5.3 Thermal performance tests
5.3.1 General
The flue damper to be tested shall be mounted in the test assembly and supported according to the
manufacturer’s instructions.
For the thermal test of the flue damper the test assembly of connecting flue pipes according to EN 1856-2
shall be used.
5.3.2 Test assembly
5.3.2.1 General
The test assembly shall comprise a test structure, a test sample, a hot gas generator and measuring
equipment, see Figures 3 a) and 3 b).
5.3.2.2 Hot gas generator connection
Construct a purpose-made insulated straight flue pipe having an nominal diameter equal to that of the
flue of the test chimney of a length of minimum seven diameters measured from the outlet of the flue gas
generator to the hot gas measuring point, insulated to provide a thermal resistance value of not less than
that equivalent to 50 mm thickness of material having a thermal conductivity of (0,125 ± 0,005) W/mK
at (750 ± 5) °C, see Figures 3 a) and 3 b).
5.3.2.3 Measuring equipment and its location
Measuring equipment shall comply with EN 1856-2:2009, A.7.1.3.
Measuring equipment for distance to combustible material of the flue damper shall be located at the
smallest distance diametrically opposite to the flue damper, sufficient to find the hottest place of the
combustible material. Measurements shall be made in two vertical points and on the ceiling, see Figure 3
a), where appropriate.
5.3.2.4 Test environment
The test room shall comply with EN 1856-2:2009, A.7.1.4.
5.3.2.5 Test structure
The test structure shall comprise the essential wall and ceiling parts of zone A of the thermal test
structure described in EN 1856-2:2009, A.7.2.2, see Figures 3 a) and 3 b).
Figure 3 a) represents the test structure for integrity and confirmation of the declared distance to the
combustible material.
Figure 3 b) represents the test structure for integrity.
The test structure can only be used for flue dampers:
— with temperature classes up to T 160 and a freely ventilated distance to combustible materials of
minimum 50 mm,
— with temperature classes T 200 and more and a freely ventilated distance to combustible materials
of minimum three times the diameter of the connecting flue pipe but not less than 375 mm,
— with a housing of the same material that is already tested according to the relevant product standard,
if the values of distance to combustible materials of the housing are declared also for the flue damper.
NOTE Freely ventilated means that ventilation of the space around the flue damper is not enclosed by e.g. fitting
it in a cupboard.
5.3.2.6 Test samples
Install a connecting flue pipe with a flue damper as shown in Figures 3 a) or 3 b).
a) — Test assembly for measuring the distance to combustible materials

b) — Test assembly for integrity test only (longitudinal section)
Key
1 flue damper
2 hot gas generator
x distance to combustible materials in mm
D nominal diameter of the flue of the test sample
Figure 3 — Test assemblies
5.3.3 Test procedure
5.3.3.1 General
Perform the thermal performance tests according to EN 1856-2:2009, A.7.4.1.
5.3.3.2 Normal operating conditions
The products shall be tested in accordance with EN 1856-2:2009, A.7.4.2 to steady-state at a test
temperature given in EN 1443:2019, Table 2, appropriate to the product characteristics.
Carry out the gas tightness test before and after the heat stress test in accordance with 5.4.
5.3.3.3 Sootfire conditions
The sootfire resistance of flue dampers (G) or sootfire safe flue dampers (As) shall be verified by a test in
accordance with EN 1856-2:2009, A.7.4.3 with a test temperature of 1 000 °C over a period of 30 min and
a hot gas velocity as given in EN 1443:2019, Table 6. The hot gas temperature shall rise gradually to
achieve 1 000 °C in 10 m
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