EN ISO 13478:2007

Thermoplastics pipes for the conveyance of fluids - Determination of resistance to rapid crack propagation (RCP) - Full-scale test (FST) (ISO 13478:2007)

ISO 13478:2007 specifies a full-scale test (FST) method for determining the arrest or propagation of a crack initiated in a thermoplastics pipe at a specified temperature and internal pressure. The method is also suitable for the determination of defined critical pressure, critical stress and critical temperature parameters.
It is applicable to the assessment of the performance of thermoplastics pipes intended for the supply of gases or liquids. In the latter case, air could also be present in the pipe.

Rohre aus Thermoplasten für den Transport von Fluiden - Bestimmung des Widerstandes gegenüber schneller Rissfortpflanzung (RCP) - Praxistest (FS-Prüfung) (ISO 13478:2007)

Diese Internationale Norm legt ein Verfahren für die FS-Prüfung zur Bestimmung des Arrestes oder der Fortpflanzung eines Risses fest, der in einem Thermoplastrohr bei festgelegter Temperatur und festgelegtem Innendruck ausgelöst wurde. Das Verfahren ist auch zur Bestimmung der festgelegten kritischen Parameter für Druck, Spannung und Temperatur geeignet.
Diese Norm gilt ebenfalls für die Bewertung der Gebrauchstauglichkeit von Thermoplastrohren für den Trans¬port von Gasen oder Flüssigkeiten. Im letzteren Fall, könnte auch Luft im Rohr zugegen sein.

Tubes en matières thermoplastiques pour le transport des fluides - Détermination de la résistance à la propagation rapide de la fissure (RCP) - Essai grandeur nature (FST) (ISO 13478:2007)

L'ISO 13478:2007 spécifie une méthode d'essai grandeur nature pour la détermination de l'arrêt ou de la propagation d'une fissure initiée dans un tube en matière thermoplastique, à une température et sous une pression interne spécifiées. La méthode convient également pour la détermination de paramètres de pression, contrainte et température critiques définis. Elle est applicable à l'évaluation de la performance des tubes en thermoplastique destinés à l'alimentation en gaz ou en liquides Dans ce dernier cas, de l'air peut également être présent dans le tube.

Plastomerne cevi za transport fluidov - Ugotavljanje odpornosti proti hitremu širjenju razpoke (RCP) - Preskus polnega obsega (Full-scale test - FST) (ISO 13478:2007)

General Information

• Status: Published
• Publication Date: 14-Aug-2007
• Withdrawal Date: 28-Feb-2008
• ICS: 23.040.20 - Plastics pipes
• Technical Committee: CEN/TC 155 - Plastics piping systems and ducting systems
• Drafting Committee: CEN/TC 155/WG 12 - Systems for water supply and pressure drainage and sewerage - PE, PP (solid wall)
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 15-Aug-2007
• Completion Date: 15-Aug-2007
• Directive: 305/2011 - Regulation (eu) No 305/2011 of the European Parliament and of the Council of 9 march 2011 laying down harmonised conditions for the marketing of construction products and repealing council directive 89/106/eec
• Directive: 89/106/EEC - Construction products
• Ref Project: SIST EN ISO 13478:2007 - Thermoplastics pipes for the conveyance of fluids - Determination of resistance to rapid crack propagation (RCP) - Full-scale test (FST) (ISO 13478:2007)

Relations

• Replaces: EN ISO 13478:1997 - Thermoplastics pipes for the conveyance of fluids - Determination of resistance to rapid crack propagation (RCP) - Full-scale test (FST) (ISO 13478:1997)
• Effective Date: 22-Dec-2008

Overview

EN ISO 13478:2007 - Thermoplastics pipes for the conveyance of fluids - Determination of resistance to rapid crack propagation (RCP) - Full‑scale test (FST) (ISO 13478:2007) specifies a full‑scale impact test to determine whether an initiated crack in an internally pressurized thermoplastics pipe will arrest or propagate rapidly. The method is applicable to pipes used for gas or liquid supply (liquid tests may include entrained air). The standard also supports determination of critical pressure, critical hoop stress, and critical temperature for RCP behaviour.

Key topics and technical requirements

• Test principle: An impact initiates a crack in a full‑length pipe (typically 14–20 m). The crack either arrests or propagates almost the full pipe length; results determine RCP resistance.
• Test environment: Pipes are maintained at a specified test temperature (controlled to ±1.5 °C along the length) in a temperature‑controlled trough; pressurizing fluid is the service fluid or an equivalent gas (air or nitrogen may be used as substitutes).
• Pressurizing fluids and conditions: The method is valid for gas or liquid service; where water contains air pockets, tests typically include 5–10% air by volume to assess RCP risk. Nitrogen/air produce slightly lower RCP pressures than natural gas (noted differences in decompression velocities).
• Apparatus essentials:
  • Temperature‑controlled trough sized for overall pipe length
  • Steel pipe reservoir with volume >= 3× test pipe volume and axial alignment
  • Initiation ring, impact (pneumatic piston and blade), end caps and backfill (washed gravel 20–40 mm)
  • Instrumentation for pressure and temperature monitoring along the pipe
• Measured parameters: Arrest vs. propagation outcome, critical pressure (pc), critical hoop stress (σc), and critical temperature (Tc). Annex A and Annex B define procedures for determining critical pressure/stress and critical temperature respectively.
• Comparison with bench methods: ISO 13478 FST reflects field‑scale decompression effects (no internal baffles) and is considered a reference for long pipelines; ISO 13477 (S4 method) uses shorter pipe samples with baffles - both methods can be correlated (correlation developed for PE pipes).

Applications and who uses it

• Manufacturers of thermoplastic pipes (PE, PVC, etc.) for gas distribution and water networks use this standard to validate RCP performance.
• Independent test laboratories and R&D teams implement FST to determine critical RCP parameters under near‑service conditions.
• Pipeline designers, utilities and regulators rely on these results for system safety assessments, material selection and compliance with product standards.
• Standards committees reference ISO 13478 when defining product specifications and acceptance criteria for pipeline systems.

Related standards

• ISO 13477 (S4 method for RCP)
• ISO 1167‑1 (resistance to internal pressure)
• ISO 3126 (plastics piping components - dimensions)
• ISO 11922‑1 (pipe dimensions and tolerances)

Keywords: EN ISO 13478:2007, ISO 13478, thermoplastics pipes, rapid crack propagation, RCP, full‑scale test, FST, critical pressure, critical temperature, hoop stress, pipeline testing.

Standards Content (Sample)

SLOVENSKI STANDARD
01-december-2007
1DGRPHãþD
SIST EN ISO 13478:1999
Plastomerne cevi za transport fluidov - Ugotavljanje odpornosti proti hitremu
širjenju razpoke (RCP) - Preskus polnega obsega (Full-scale test - FST) (ISO
13478:2007)
Thermoplastics pipes for the conveyance of fluids - Determination of resistance to rapid
crack propagation (RCP) - Full-scale test (FST) (ISO 13478:2007)
Rohre aus Thermoplasten für den Transport von Fluiden - Bestimmung des
Widerstandes gegenüber schneller Rissfortpflanzung - Praxistest (FST) (ISO
13478:2007)
Tubes en matieres thermoplastiques pour le transport des fluides - Détermination de la
résistance a la propagation rapide de fissure (RCP) - Essai grandeur nature (FST) (ISO
13478:2007)
Ta slovenski standard je istoveten z: EN ISO 13478:2007
ICS:
23.040.20 Cevi iz polimernih materialov Plastics pipes
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN ISO 13478
NORME EUROPÉENNE
EUROPÄISCHE NORM
August 2007
ICS 23.040.20 Supersedes EN ISO 13478:1997
English Version
Thermoplastics pipes for the conveyance of fluids -
Determination of resistance to rapid crack propagation (RCP) -
Full-scale test (FST) (ISO 13478:2007)
Tubes en matières thermoplastiques pour le transport des Rohre aus Thermoplasten für den Transport von Fluiden -
fluides - Détermination de la résistance à la propagation Bestimmung des Widerstandes gegenüber schneller
rapide de la fissure (RCP) - Essai grandeur nature (FST) Rissfortpflanzung (RCP) - Praxistest (FS-Prüfung) (ISO
(ISO 13478:2007) 13478:2007)
This European Standard was approved by CEN on 30 June 2007.
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 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 Management Centre has the same status as the
official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2007 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 13478:2007: E
worldwide for CEN national Members.

Contents Page
Foreword.3

Foreword
This document (EN ISO 13478:2007) has been prepared by Technical Committee ISO/TC 138 "Plastics pipes,
fittings and valves for the transport of fluids" in collaboration with Technical Committee CEN/TC 155 “Plastics
piping systems and ducting systems” the secretariat of which is held by NEN.
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 February 2008, and conflicting national standards shall be withdrawn
at the latest by February 2008.
This document supersedes EN ISO 13478:1997.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.
Endorsement notice
The text of ISO 13478:2007 has been approved by CEN as a EN ISO 13478:2007 without any modification.

INTERNATIONAL ISO
STANDARD 13478
Second edition
2007-08-15
Thermoplastics pipes for the conveyance
of fluids — Determination of resistance to
rapid crack propagation (RCP) —
Full-scale test (FST)
Tubes en matières thermoplastiques pour le transport des fluides —
Détermination de la résistance à la propagation rapide de la fissure
(RCP) — Essai grandeur nature (FST)

Reference number
ISO 13478:2007(E)
©
ISO 2007
ISO 13478:2007(E)
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ii © ISO 2007 – All rights reserved

ISO 13478:2007(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions. 1
4 Symbols . 2
5 Principle. 2
6 Test parameters . 3
7 Materials . 3
8 Apparatus . 3
9 Test-pipe preparation . 7
10 Conditioning and backfill. 7
11 Test procedure . 8
12 Validity of results. 8
13 Test report . 9
Annex A (normative) Determination of critical pressure (or hoop stress). 10
Annex B (normative) Determination of critical temperature. 13
Bibliography . 14

ISO 13478:2007(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 13478 was prepared by Technical Committee ISO/TC 138, Plastics pipes, fittings and valves for the
transport of fluids, Subcommittee SC 5, General properties of pipes, fittings and valves of plastic materials and
their accessories — Test methods and basic specifications.
This second edition cancels and replaces the first edition (ISO 13478:1997), which has been technically
revised.
iv © ISO 2007 – All rights reserved

ISO 13478:2007(E)
Introduction
Test methods that measure the resistance of internally pressurized plastics pipes to rapid fracture propagation
[1]
(RCP) have been standardized: ISO 13477 and this International Standard. The S4 method specified in

ISO 13477 utilizes short lengths of pipe to determine a critical RCP pressure or temperature for the pipe.
Longer pipes up to 20 m in length are the basis of this full-scale test (FST) method for measurement of these
critical parameters. On the one hand, the S4 method uses internal baffles to prevent rapid decompression of
the internal test pressure, thus ensuring that the high-speed crack tip is exposed to the full pipe pressure
throughout the test. The FST, on the other hand, has no baffles installed and is more related to field service.
The crack tip is subjected to a reducing pressure by decompression effects as the crack propagates. This
arrangement reflects the RCP mode of failure of long pipelines and is assumed to be the reference test
method. The critical RCP values derived from each test are different but can be correlated experimentally. A
mathematical equation for correlation has been developed for polyethylene (PE) pipes (see ISO 13477).

INTERNATIONAL STANDARD ISO 13478:2007(E)

Thermoplastics pipes for the conveyance of fluids —
Determination of resistance to rapid crack propagation (RCP) —
Full-scale test (FST)
1 Scope
This International Standard specifies a full-scale test (FST) method for determining the arrest or propagation
of a crack initiated in a thermoplastics pipe at a specified temperature and internal pressure. The method is
also suitable for the determination of defined critical pressure, critical stress and critical temperature
parameters.
It is applicable to the assessment of the performance of thermoplastics pipes intended for the supply of gases
or liquids. In the latter case, air could also be present in the pipe.
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 1167-1, Thermoplastics pipes, fittings and assemblies for the conveyance of fluids — Determination of
the resistance to internal pressure — Part 1: General method
ISO 3126, Plastics piping systems — Plastics components — Determination of dimensions
ISO 11922-1, Thermoplastics pipes for the conveyance of fluids — Dimensions and tolerances — Part 1:
Metric series
3 Terms and definitions
For the purposes of this International Standard, the terms and definitions given in ISO 11922-1 and the
following apply.
3.1
critical pressure
p
c
highest crack-arrest pressure below the lowest crack-propagation pressure
3.2
critical hoop stress
σ
c
highest crack-arrest hoop stress below the lowest crack-propagation hoop stress
3.3
critical temperature
T
c
lowest crack-arrest temperature above the highest crack-propagation temperature
ISO 13478:2007(E)
3.4
crack arrest
event characterized by the length of the longest crack that is less than or equal to 90 % of the length of the
test pipe
3.5
rapid crack propagation
RCP
event characterized by the length of the longest crack that is greater than 90 % of the length of the test pipe
4 Symbols
1)
p test pressure, in bar
1)
p critical pressure, in bar
c
σ critical hoop stress, in megapascals (MPa)
c
T critical temperature, in degrees Celsius (°C)
c
d mean outside diameter of test pipe, in millimetres
em
D average of the mean outside diameters, d , of the pipe sections, in millimetres
em
e mean wall thickness of the test pipe along the (main) crack, in millimetres.
t
5 Principle
A thermoplastics pipe, maintained at a specified temperature and containing a fluid at a specified test
pressure, is subjected to an impact designed to initiate a crack. The crack can then arrest within a short
distance or continue to propagate at high speed along the pipe.
The test temperature and test pressure are as defined in the referring standard and are related to the intended
operating conditions.
The pressurizing fluid is identical to that used in the intended application, or else is a substitute fluid, e.g. air or
nitrogen, which gives equivalent results.
The test simulates the performance of a buried pipe in service under conditions which do not retard the rate of
decompression of the pressurizing fluid through any fracture.
The pipe is subsequently examined to determine whether arrest or propagation of the crack has occurred.
From a series of such tests at different pressures but at a constant temperature, a critical pressure or critical
stress for crack propagation can be determined (see Annex A).
Similarly, by testing at a series of temperatures while maintaining a constant pressure or hoop stress, the
critical temperature for RCP can be determined (see Annex B).

5 2
1) 1 bar = 0,1 MPa = 10 Pa; 1 MPa = 1 N/mm .
2 © ISO 2007 – All rights reserved

ISO 13478:2007(E)
6 Test parameters
It is assumed that the following parameters will be set by the referring product standard:
a) the diameter(s) and series of the pipe(s) to be tested;
b) the pressurizing fluid (7.4), e.g. gas, water, water plus air or nitrogen;
c) the test pressure(s);
d) the test temperature(s).
7 Materials
7.1 Methylated spirits or ethanol, for use as a cooling fluid (see 8.4.3).
7.2 Solid carbon dioxide, for use as a cooling agent (see 8.4.3).
7.3 Washed gravel, with a size range of 20 mm to 40 mm diameter (see Clause 10).
7.4 Pressurizing fluid, which shall be as specified in the referring standard.
NOTE 1 It is satisfactory to use nitrogen or air as the pressurizing fluid instead of natural gas, as the measured
pressure for rapid crack propagation (RCP) will be only slightly less than that obtained with natural gas. The
decompression speed (velocity of sound) at 0 °C of nitrogen and air is 337 m/s and 334 m/s, respectively, compared with
approximately 430 m/s for natural gas.
NOTE 2 In water-pipeline systems, which contain water only, the phenomenon of crack propagation is unlikely to occur.
However, when entrained air bubbles or air pockets are present, it is possible. It is usual to test with between 5 % and
10 % by volume of air in the water to determine the resistance to crack propagation. A test on water pipe using 100 % gas,
air or nitrogen is more likely to result in RCP and therefore will be expected to give a pessimistic result (also see
Reference [2] for RCP testing of pipes filled or partially filled with water).
8 Apparatus
8.1 Temperature-controlled trough, capable of accommodating the overall pipe length normally of 14 m
to 20 m (also see Clause 9). The trough shall have means for maintaining the temperature specified by the
referring standard to within ± 1,5 °C along the whole test pipe length. The temperature may be controlled by
recirculation of water or air around the test pipe (see Figure 1). The temperature shall be monitored at
intervals along the test length. If necessary, the water shall contain antifreeze to avoid ice build-up around the
test pipe.
NOTE Temperature monitoring along the test length at intervals not exceeding 3 m and around the pipe at the
3 o’clock and 9 o’clock positions has been found to be satisfactory.
ISO 13478:2007(E)
Dimensions in millimetres
Key
l test length (overall pipe length, l, 14 m to 20 m)
t
1 steel pipe reservoir
2 gravel
3 required butt-fusion joints
4 initiation ring
5 cooling trough
6 pneumatic piston
7 blade
8 end cap
Figure 1 — Example of test facility for full-scale rapid crack propagation
8.2 Steel-pipe reservoir, connected to the test pipe at one end of the trough. The steel pipe shall have a
bore diameter greater than or equal to the test-pipe bore diameter. The pipe reservoir shall have a minimum
length of twice that of the test pipe and a minimum volume of three times that of the test pipe.
Axial alignment of the reservoir with the test pipe is preferred.
8.3 Pressurization equipment, for pressurizing the test pipe and steel reservoir (8.2) with the test fluid
(7.4
...