ISO 20632:2008

INTERNATIONAL ISO
STANDARD 20632
First edition
2008-04-01

Reaction-to-fire tests — Small room test
for pipe insulation products or systems
Essais de réaction au feu — Essai en chambre de petite taille de
produits ou systèmes de calorifugeage de tuyauterie




Reference number
ISO 20632:2008(E)
©
ISO 2008

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ISO 20632:2008(E)
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ISO 20632:2008(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions. 1
4 Principle. 2
5 Test room. 2
6 Ignition source . 2
7 Hood and exhaust duct . 4
8 Instrumentation in the exhaust duct. 4
8.1 Volume flow rate . 4
8.2 Gas analysis . 4
8.3 Optical density . 4
9 System performance . 6
9.1 Calibration . 6
9.2 System response . 6
9.3 Precision. 6
10 Preparation of test specimens . 6
10.1 Test specimen configuration. 6
10.2 Mounting of insulation on pipes . 6
10.3 Dimensions of test specimen . 7
11 Testing . 7
11.1 Initial conditions . 7
11.2 Test procedure . 8
12 Sensitivity analysis. 8
13 Precision data . 8
14 Test report . 9
Annex A (normative) Test specimen configuration. 10
Annex B (normative) Calculations.15
Annex C (informative) Design of exhaust system. 20
Annex D (informative) Instrumentation in exhaust duct . 23
Bibliography . 29

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ISO 20632:2008(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 20632 was prepared by Technical Committee ISO/TC 92, Fire safety, Subcommittee SC 1, Fire initiation
and growth.
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ISO 20632:2008(E)
Introduction
The test method described in this document is intended to assess the fire performance of a pipe insulation
product, supported on a steel pipe, under controlled conditions.
The method can be used as part of a fire hazard assessment that takes into account all of the factors that are
pertinent to a particular end use of a pipe insulation product.

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INTERNATIONAL STANDARD ISO 20632:2008(E)

Reaction-to-fire tests — Small room test for pipe insulation
products or systems
Caution — So that suitable precautions can be taken to safeguard health, the attention of all
concerned in fire tests is drawn to the possibility that toxic or harmful gases can be evolved during
combustion of the test specimen.
The test procedures involve high temperatures and combustion processes from ignition to a fully
developed room fire. Therefore, hazards can exist for burns, ignition of extraneous objects or clothing.
The operators should use protective clothing, helmet, face-shield and equipment for avoiding
exposure to toxic gases.
1 Scope
This International Standard specifies a test method for determining the reaction to fire performance of pipe
insulation products and some pipe insulation systems installed in a small room.
The scenario is valid for fires in a room where pipe insulation products are installed within building applications,
e.g. pipe and duct rooms in public buildings, apartment blocks, hospitals and ships.
This method is suitable for products that cannot be tested in a small-scale test, or for correlation of small-scale
test data. The method can also serve as a reference scenario for pipe insulation products or for systems fitted
in a room within a building or a ship.
The method is not suitable for pipe insulation in concealed spaces, such as a horizontal or a vertical shaft.
This method is not intended for evaluating the fire resistance of pipe insulation systems.
2 Normative references
The following referenced documents are indispensable for the application 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.
ISO 9705:1993, Fire tests — Full-scale room test for surface products
ISO 13943, Fire safety — Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 13943 and the following apply.
3.1
pipe insulation product
thermally-insulating material or product that covers a pipe
NOTE One layer is an insulating material, such as mineral or glass wool or cellular plastics. Facings on one or both
sides can protect this insulating layer. Facings can be selected from a variety of materials, such as aluminium foil or glass
fibre reinforced resin. The insulating material can be preformed, sprayed or wrapped around the pipe.
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ISO 20632:2008(E)
3.2
pipe insulation system
system comprising the pipe, the pipe insulation product, a product to keep the joint together such as tape or
steel wire, possibly a finish layer or jacketing and pipe hangers
NOTE Pipe hangers can be fitted on the steel pipe (hot applications) or on the insulation product (cold applications).
4 Principle
The test methodology for determining the reaction to fire performance of pipe insulation products consists of
assessing the following hazards:
⎯ the potential of fire growth along the lines of pipes in the room by measurement of heat release rate,
HRR;
⎯ the potential for sustained fire and subsequent spread by measurement of the total heat release, THR;
⎯ the potential to reach flashover and spread fire outside the room;
⎯ reduced visibility by the measurement of light-obscuring smoke;
⎯ potential for discontinuous fire spread by observation of flaming droplets/particles.
5 Test room
The test room dimensions, the position and size of the doorway and the construction material shall be as
described in ISO 9705.
6 Ignition source
The ignition source shall be identical to the recommended standard ignition source described in Annex A of
ISO 9705:1993. The position of the burner shall be 50 mm above floor level.
The ignition source shall be a propane gas burner having a square top surface layer of a porous, inert material,
e.g. sand. The burner shall have face dimensions of 170 mm × 170 mm and a height of 200 mm above the
floor (see Figure 1). The construction shall be such that an even gas flow is achieved over the entire opening
area.
The ignition source is a propane gas burner that consumes relatively large amounts of gas. The attention of all
concerned in fire tests is therefore drawn to the following warning.
WARNING — All equipment such as tubes, couplings, flowmeters, etc., shall be approved for propane
and installed according to good practice. For reasons of safety, the burner should be equipped with a
remote-controlled ignition device, for example, a pilot flame or a glow wire. There should be a warning
system for gas leakage and a valve for immediate and automatic cut-off of the gas supply in case of
extinction of the ignition flame.
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ISO 20632:2008(E)
Dimensions in millimetres

Key
1 gas inlet
2 sand (2 mm – 3 mm)
3 brass wire gauze (Ø1,8 mm)
4 gravel (4 mm – 8 mm)
5 brass wire gauze (Ø 2,8 mm)
Figure 1 — Standard ignition source (top view and cross section A-A)
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ISO 20632:2008(E)
The burner shall be placed on the floor in a corner opposite to the doorway wall. The burner walls shall be in
contact with the specimen.
The burner shall be supplied with propane with a purity of at least 95 %. The gas flow to the burner shall be
measured to an accuracy of at least ± 3 %. The heat output to the burner shall be controlled to within ± 5 % of
the prescribed value.
The burner power output, based on the net (lower) calorific value of propane, shall be 100 kW during the first
10 min and then shall be increased to 300 kW for a further 10 min.
7 Hood and exhaust duct
The system for collecting the combustion products shall have such a capacity and be designed in such a way
that all of the combustion products leaving the fire room through the doorway during a test are collected. The
system shall not disturb the fire-induced flow in the doorway. The maximum exhaust capacity shall be at least
3 −1
3,5 m s at normal pressure and a temperature of 25 °C.
NOTE An example of one design of hood and an exhaust duct is given in Annex C.
8 Instrumentation in the exhaust duct
8.1 Volume flow rate
The volume flow rate in the exhaust duct shall be measured to an accuracy of at least ± 5 %.
The response time to a stepwise change of the duct flow rate shall be a maximum of 1 s at 90 % of the final
value.
8.2 Gas analysis
8.2.1 Sampling line
The gas samples shall be taken in the exhaust duct at a position where the combustion products are uniformly
mixed. The sampling line shall be made from an inert material which will not influence the concentration of the
gas species to be analysed. (See Annex D.)
8.2.2 Oxygen
The oxygen consumption shall be measured to an accuracy of at least ± 0,05 % (volume fraction) oxygen. The
oxygen analyser shall have a time constant not exceeding 3 s. (See Annex D.)
8.2.3 Carbon monoxide and carbon dioxide
The gas species shall be measured using analysers having an accuracy of at least ± 0,1 % (volume fraction)
for carbon dioxide and ± 0,02 % (volume fraction) for carbon monoxide. The analysers shall have a time
constant not exceeding 3 s. (See Annex D.)
8.3 Optical density
8.3.1 General
The optical density of the smoke shall be determined by measuring the light obscuration with a system
consisting of a lamp, lenses, an aperture and a photocell (see Figure 2). The system shall be constructed in
such a way as to ensure that soot deposits during the test do not reduce the light transmission by more than
5 %.
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ISO 20632:2008(E)
8.3.2 Lamp
The lamp shall be of the incandescent filament type and shall operate at a colour temperature of
2 900 K ± 100 K. The lamp shall be supplied with stabilized direct current, stable to within ± 0,2 % (including
temperature, short-term and long-term stability).
8.3.3 Lenses
The lens system shall align the light to a parallel beam with a diameter, D, of at least 20 mm.
8.3.4 Aperture
The aperture shall be placed at the focus of the lens L2 as shown in Figure 2 and it shall have a diameter, d,
chosen with regard to the focal length, f, of L2 so that d/f is less than 0,04.
8.3.5 Detector
1)
The detector shall have a spectrally distributed responsivity agreeing with the CIE , V (λ)-function (with CIE
photopic curves to an accuracy of at least ± 5 %.
The detector output shall be linear to within 5 % over an output range of at least 3,5 decades.
8.3.6 Location
The light beam shall cross the exhaust duct along its diameter at a position where the smoke is homogenous.

Key
1 wall of exhaust duct
2 lamp
3 aperture
4 detector
L1 and L2: lenses of focal length f
Figure 2 — Optical system

1) Commission internationale d’éclairage (International Commission on Illumination).
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ISO 20632:2008(E)
9 System performance
9.1 Calibration
A calibration test shall be performed prior to each test or continuous test series.
NOTE Equations for calculations are given in Annex B.
The calibration shall be performed at the burner heat outputs given in Table 1, with the burner positioned
directly under the hood. Measurements shall be taken every 3 s and shall be started 1 min prior to ignition of
the burner. At steady state conditions, the difference between the mean heat release rate over 1 min
calculated from the measured oxygen consumption and that calculated from the metered gas input shall not
exceed 5 % for each level of heat output.
Table 1 — Burner heat output profile
Time Heat output
min kW
0 to 2 0
2 to 7 100
7 to 12 300
12 to 17 100
17 to 19 0
9.2 System response
The time delay for a stepwise change of the heat output from the burner, when placed centrally 1 m below the
hood, shall not exceed 20 s and shall be corrected for in-test data. The time delay for each step shall be
determined by measuring the time taken to reach agreement to within 10 % of the difference between the
initial and final measured heat release value, when going through the stepwise procedure given in Table 1,
taking measurements at 3 s intervals.
9.3 Precision
The precision of the system at various volume flow rates shall be checked by increasing the volume flow in the
3 −1
exhaust duct in four equal steps, starting from 2 m s (at 0,1 MPa and 25 °C) up to maximum. The heat
output from the burner shall be 300 kW. The error in the mean heat release rate, calculated over 1 min, shall
be no more than 10 % of the actual heat output from the burner.
10 Preparation of test specimens
10.1 Test specimen configuration
The pipe insulation product shall be mounted as closely as possible to the end use application conditions. It
shall be mounted and fixed as pipe sections with a (25 ± 1) mm gap maintained between each of the insulated
pipe runs according to the configuration given in Annex A. A three-dimensional view is given in Figure 3.
10.2 Mounting of insulation on pipes
Pipe insulation shall be mounted and fixed on steel pipes. The steel pipes shall have an outside diameter of
(21,3 ± 0,1) mm and a thickness of (2,55 ± 0,05) mm.
[1]
NOTE 1 Steel pipes produced according to ISO 65 , medium series, fulfil these criteria.
NOTE 2 The standard configuration is steel pipes, but other types of pipe can be tested if required.
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ISO 20632:2008(E)

NOTE The roof and left wall of the room corner have been removed for better view.
Figure 3 — Three-dimensional view of the test specimen configuration
10.3 Dimensions of test specimen
Pipe insulation shall be tested with an inner diameter of (22,0 ± 0,5) mm and an insulation thickness of
between 25 mm and 50 mm.
NOTE 1 Some rules can be considered when examining the reaction to fire performance of ranges of pipe insulation,
e.g.:
a) test data on pipe insulation with an inner diameter of 22 mm might be applicable for other inner diameters; however,
intermediate bore diameters, i.e. greater than 50 mm, might not be covered by this test and ad hoc testing is
recommended;
b) test data on pipe insulation with 25 mm thickness can also be valid for smaller thicknesses.
c) test data on pipe insulation with 50 mm thickness can be valid for larger thicknesses.
NOTE 2 Lower thicknesses can be tested but in this case the result is only valid for that specific thickness.
11 Testing
11.1 Initial conditions
11.1.1 The temperature in the test room from the start of the installation of the specimens until the start of the
test shall be between 10 °C and 30 °C.
NOTE The time between the removal of the specimens from the conditioning room and the start of the test should be
kept to a minimum.
−1
11.1.2 The horizontal wind speed measured to an accuracy of 0,12 m s at a horizontal distance of 1 m
−1
external from the centre of the doorway shall not exceed 0,5 m s .
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ISO 20632:2008(E)
11.1.3 The burner shall be in contact with the test specimen in the corner opposite the doorway. The surface
area of the burner opening shall be clean.
11.1.4 The pipe insulation assembly shall be photographed or video recorded before testing.
11.2 Test procedure
11.2.1 Start all recording and measuring devices and record data at least 2 min prior to the burner being
ignited. Use a 3 s interval.
11.2.2 Adjust the burner to the output level given in Clause 6 (see last paragraph) within 10 s of ignition.
Continuously adjust the exhaust capacity so that all combustion products are collected.
11.2.3 Make a photographic and/or video recording of the test, with a timer appearing in all photographic
records, giving time to the nearest second.
11.2.4 During the test, record the following observations, including the time when they occur:
a) ignition of the test specimen, and any glowing or smouldering that might occur;
b) the surface spread of flame on the test specimen through measurement of the distance of damaged
length;
c) occurrence and location of flaming droplets/particles that fall outside a zone measuring 1,2 m from the
corner line of the corner where the burner is placed;
d) flames emerging through the doorway and whether these are transient flames or sustained flames;
e) flashover (corresponding to a heat release rate in the exhaust duct of 1 000 kW, including the contribution
of the burner).
11.2.5 Stop the test if flashover occurs, or after 20 min from ignition of the burner, whichever occurs first.
Continue observations until visual signs of combustion have ceased.
NOTE Safety considerations can dictate an earlier termination.
11.2.6 Note the extent and type of damage of the product after the test.
11.2.7 Record any other unusual performance.
12 Sensitivity analysis
Variation of fire load by either changing the number of pipes or by changing the insulation thickness from
25 mm to 50 mm is not expected to change the ranking order according to the fire performance of the
products.
NOTE See, for example, Bibliography [4].
13 Precision data
The precision of this test method has not been determined. Results of a planned inter-laboratory test series
will be included when available.
NOTE Repeatability has been studied in a European project and data are available. See Bibliography [4].
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ISO 20632:2008(E)
14 Test report
The test report shall contain the following information:
a) name and address of the testing laboratory;
b) date and identification number of the report;
c) name and address of the sponsor;
d) purpose of the test;
e) method of sampling;
f) name and address of the manufacturer or supplier of the product;
g) name or other identification marks and description of the product;
h) density and thickness of the product;
i) date of supply of the product;
j) description of the test specimens and detailed mounting technique, i.e. clamps, fixing, etc.;
k) conditioning of the test specimens;
l) date of test;
m) test method and reference to this International Standard, i.e. ISO 20632:2007;
n) test results (see Annex B):
1) time to flashover (see Clause B.5);
 
2) time/heat release rate,q, and, if the burner is included, time/heat release rate from the burner,q ;
b
3) time/smoke production rate, R , at actual duct flow temperature;
inst
4) description of the fire development (including photographs taken during the test);
5) total smoke production, R , calculated according to B.4.2 and specifying the time of integration;
tot
6) total heat released, Q , calculated according to B.2.3 and specifying the time of integration;
tot
7) visual observations of flame spread and any flaming droplets/particles;
o) optional test results:
1) time/volume flow in the exhaust duct;
2) time/production of carbon monoxide at reference temperature and pressure;
3) time/production of carbon dioxide at reference temperature and pressure;
p) on request of the sponsor, data file with data recorded automatically according to Clause 9 and/or latest
calibration reports;
q) the statement “The test results relate only to the performance of the test specimens of a product under
the particular conditions of the test; they are not intended to be the sole criterion for assessing the
potential fire hazard of the material in use”.
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ISO 20632:2008(E)
Annex A
(normative)

Test specimen configuration
The pipe insulation shall be mounted on the ceiling and along the walls as schematically illustrated in
Figures A.1 to A.4.
NOTE 1 The drawings in this annex assume a 25 mm insulation thickness but the same principles can be applied for
thicknesses up to 50 mm, keeping the spacing between insulation surfaces and with the wall to 25 mm.
Tolerances given in the main body shall apply to these figures. For those dimensions where no specific
tolerances are given in the figures or main body, standard technical tolerances shall apply.
NOTE 2 The mounting of the pipe insulation should follow end-use mounting and details of clamps, fixing, joints, etc.,
should be reported in detail.
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ISO 20632:2008(E)
Dimensions in millimetres

Key
1 tubes
X detail of corner, given in Figure A.2
Y view of the end wall, given in Figure A.3
Z view of the side wall, given in Figure A.4
Figure A.1 — Example of test specimen configuration, plan view of top of room
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ISO 20632:2008(E)

Key
1 pipe hanger
2 tube R-022 (ISO 65)
3 tubes installed on ceiling
Figure A.2 — Example of test specimen configuration, elevation of corner detail
(detail X from Figure A.1)
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ISO 20632:2008(E)
Dimensions in millimetres

Figure A.3 — Example of test specimen configuration, elevation of end wall
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ISO 20632:2008(E)

Key
1 pipe hanger
Figure A.4 — Example of test specimen configuration, side elevation near side wall

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ISO 20632:2008(E)
Annex B
(normative)

Calculations
B.1 Volume flow

The volume flow in the exhaust duct, V , expressed in cubic metres per second, related to atmospheric
298
pressure and an ambient temperature of 25 °C, shall be calculated by the equation
1
12//12
&
V=×()Akk//×(2∆pT ρ T)=22,4()Akk/(∆p/T) (B.1)
298 t p o o s t p s
ρ
298
where
T is the gas temperature in the exhaust duct, expressed in kelvins;
s
T = 273,15 K;
o
∆p is the pressure difference measured by the bi-directional probe, expressed in pascals;
ρ is the air density at 25 °C and atmospheric pressure, expressed in kilograms per cubic metre;
298
ρ is the air density at 0 °C and 0,1 MPa, expressed in kilograms per cubic metre;
o
A is the cross-sectional area of exhaust duct, expressed in square metres;
k is the ratio of the average mass flow per unit area to mass flow per unit area in the centre of the
t
exhaust duct;
k is the Reynolds number correction for the bi-directional probe, taken as constant and equal to 1,08.
p
Equation (B.1
...