Railway applications - Braking - Brake pipe accelerator

This document is applicable to brake pipe accelerator valves designed to vent the brake pipe of railway vehicles when an emergency brake application is initiated, without taking the type of vehicles and track-gauge into consideration.
This document specifies the requirements for the design, manufacture and testing of brake pipe accelerator valves.

Bahnanwendungen - Bremse - Schnellbremsbeschleuniger

Dieses Dokument gilt für Schnellbremsbeschleuniger zur Entlüftung der Hauptluftleitung von Eisenbahnfahrzeugen bei Auslösen einer Schnellbremsung ohne Berücksichtigung der Fahrzeugart oder Spurweite.
Dieses Dokument legt die Anforderungen für die Konstruktion, die Herstellung und Prüfung von Schnellbremsbeschleunigern fest.

Applications ferroviaires - Freinage - Accélérateur de vidange de conduite

Le présent document s’applique aux valves accélératrices de vidange conçues pour purger la conduite générale de véhicules ferroviaires lors d’un freinage d’urgence, indépendamment du type de véhicules ou de l’écartement de la voie.
Le présent document spécifie les exigences relatives à la conception, à la fabrication et aux essais des valves accélératrices de vidange.

Železniške naprave - Zavore - Pospešilnik praznjenja glavnega zavornega voda

General Information

Status
Published
Public Enquiry End Date
31-Dec-2018
Publication Date
19-Jul-2020
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
01-Jul-2020
Due Date
05-Sep-2020
Completion Date
20-Jul-2020

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SLOVENSKI STANDARD
SIST EN 15612:2020
01-oktober-2020
Nadomešča:
SIST EN 15612:2009+A1:2011
Železniške naprave - Zavore - Pospešilnik praznjenja glavnega zavornega voda
Railway applications - Braking - Brake pipe accelerator
Bahnanwendungen - Bremse - Schnellbremsbeschleuniger
Applications ferroviaires - Freinage - Accélérateur de vidange de conduite
Ta slovenski standard je istoveten z: EN 15612:2020
ICS:
45.040 Materiali in deli za železniško Materials and components
tehniko for railway engineering
SIST EN 15612:2020 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 15612:2020

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SIST EN 15612:2020


EN 15612
EUROPEAN STANDARD

NORME EUROPÉENNE

June 2020
EUROPÄISCHE NORM
ICS 45.040 Supersedes EN 15612:2008+A1:2010
English Version

Railway applications - Braking - Brake pipe accelerator
Applications ferroviaires - Freinage - Accélérateur de Bahnanwendungen - Bremse -
vidange de conduite Schnellbremsbeschleuniger
This European Standard was approved by CEN on 13 April 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 15612:2020 E
worldwide for CEN national Members.

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SIST EN 15612:2020
EN 15612:2020 (E)
Contents Page
European foreword . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 6
4 Design and manufacture . 7
4.1 General . 7
4.2 Functional requirements. 7
4.2.1 General . 7
4.2.2 Operating requirements . 7
4.2.3 Train behaviour . 7
4.2.4 Effect of overcharge . 7
4.2.5 Effect of individual vehicle . 8
4.2.6 Subsequent emergency braking . 8
4.2.7 Sensitivity . 8
4.2.8 Insensitivity to brake pipe pressure fall . 8
4.2.9 Insensitivity to distributor valve quick service device operation . 8
4.2.10 Tightness . 9
4.3 Shock and vibration requirements . 10
4.4 Environment requirements . 10
4.4.1 General . 10
4.4.2 Temperature . 10
4.4.3 Other environmental conditions . 10
4.5 Compressed air quality . 11
4.6 Fire behaviour . 11
4.7 External appearance . 12
4.8 Design requirements regarding pressure stress . 12
4.9 Interfaces . 12
4.9.1 General . 12
4.9.2 Mechanical . 12
4.9.3 Pneumatic . 12
5 Type tests . 12
5.1 General . 12
5.2 Individual brake pipe accelerator tests . 12
5.2.1 Test bench for individual brake pipe accelerator tests . 12
5.2.2 Sampling for type tests . 14
5.2.3 Test temperature and air quality . 14
5.2.4 Procedure for type tests . 14
5.2.5 Operation at extreme temperatures . 17
5.3 Simulated train consist tests . 18
5.3.1 Simulated train consist test bench . 18
5.3.2 Sampling for train consist test . 18
5.3.3 Test temperature and air quality . 18
5.3.4 Test procedure . 19
6 In-service assessment. 20
2

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SIST EN 15612:2020
EN 15612:2020 (E)
7 Designation . 20
8 Identification and marking . 20
Annex A (normative) In-service assessment . 21
Annex ZA (informative) Relationship between this European Standard and the Essential
Requirements of EU Directive 2016/797/EU aimed to be covered. 22
Bibliography . 24

3

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SIST EN 15612:2020
EN 15612:2020 (E)
European foreword
This document (EN 15612:2020) has been prepared by Technical Committee CEN/TC 256 “Railway
applications”, the secretariat of which is held by DIN.
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 December 2020, and conflicting national standards
shall be withdrawn at the latest by December 2020.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 15612:2008+A1:2010.
The main changes compared to EN 15612:2008+A1:2010 are:
a) the standard’s title has been modified;
b) normative references have been updated;
c) terms and definitions have been revised;
d) requirements on design and manufacture have been revised;
e) requirements on materials have been removed;
f) requirements on type tests have been revised;
g) requirements on routine test and inspection have been removed;
h) requirements on documentation have been removed;
i) requirements on identification and marking have been revised;
j) Annex ZA has been updated.
This document has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association, and supports essential requirements of EU Directive 2016/797/EU.
For relationship with EU Directive 2016/797/EU, see informative Annex ZA, which is an integral part of
this document.
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.
4

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SIST EN 15612:2020
EN 15612:2020 (E)
1 Scope
This document is applicable to brake pipe accelerators designed to vent the brake pipe of railway
vehicles when an emergency braking is initiated, without taking the type of vehicles and track-gauge
into consideration.
This document specifies the requirements for the design, manufacture and testing of brake pipe
accelerators.
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 14478:2017, Railway applications – Braking – Generic vocabulary
EN 14601:2005+A1:2010, Railway applications – Straight and angled end cocks for brake pipe and main
reservoir pipe
EN 15355:2019, Railway applications – Braking – Distributor valves and distributor-isolating devices
EN 45545-2:2013+A1:2015, Railway applications – Fire protection on railway vehicles – Part 2:
Requirements for fire behaviour of materials and components
EN 50125-1:2014, Railway applications – Environmental conditions for equipment – Part 1: Rolling stock
and on-board equipment
EN 60721-3-5:1997, Classification of environmental conditions – Part 3: Classification of groups of
environmental parameters and their severities – Section 5: Ground vehicle installations
(IEC 60721-3-5:1997)
EN 61373:2010, Railway applications – Rolling stock equipment – Shock and vibration tests
(IEC 61373:2010)
EN ISO 228-1:2003, Pipe threads where pressure-tight joints are not made on the threads – Part 1:
Dimensions, tolerances and designation (ISO 228-1:2000)
ISO 8573-1:2010, Compressed air – Part 1: Contaminants and purity classes
5

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SIST EN 15612:2020
EN 15612:2020 (E)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 14478:2017 and the following
apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at https://www.iso.org/obp/ui
3.1
brake pipe accelerator
component connected to the brake pipe that, in response to a brake command, assists the propagation
of the brake command throughout the train by locally venting the brake pipe (see Figure 1)

Key
1 input pressure (brake pipe)
2 brake pipe accelerator
3 exhaust
Figure 1 — Brake pipe accelerator, main function and block diagram
[SOURCE: EN 14478:2017, 4.10.3.7, modified – Note 1 to entry has been deleted; “(see Figure 1)” has
been added at the end of the definition; Figure and key have been added to the definition.]
3.2
normal litre
NI
unit of amount of a gas equal to the amount of 1 l at a pressure of 1,0 bar and at a standard temperature,
at 20 °C
Note 1 to entry: Airflow is often stated in normal litres per minute (NI/min).
3.3
quick service function
function of a distributor valve which allows, when applying the brake both from stand-by and released
position, the local fast venting of brake pipe pressure by a certain specified amount and at a certain
specified gradient, to provide pneumatic brake signal transmission through a train
3.4
quick service device
device that fulfils the quick service function
3.5
emergency braking
brake pipe pressure fall at the accelerator valve as a result of a demand for an emergency braking from
any source
6

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SIST EN 15612:2020
EN 15612:2020 (E)
3.6
overcharge
increase in brake pipe pressure above normal working pressure
4 Design and manufacture
4.1 General
The design and manufacture of the brake pipe accelerators shall comply with this document.
4.2 Functional requirements
4.2.1 General
Brake pipe accelerators shall be able to operate with all distributors valves that conform with
EN 15355:2019 and all existing brake pipe accelerators that comply with the requirements of this
document.
The brake pipe accelerator shall be ready to operate when the brake pipe has reached the normal
working pressure. The brake pipe accelerator shall operate in response to a defined rapid fall of brake
pipe pressure to ensure a continuing rapid fall to below 2,5 bar.
4.2.2 Operating requirements
The following operating requirements are defined in relation to the normal working pressure of
(5,00 ± 0,05) bar. When an emergency braking occurs, the brake pipe accelerators shall create a
sufficiently rapid reduction in brake pipe pressure to ensure the rapid increase in brake cylinder
pressure on every vehicle in the train set. When the pressure in the brake pipe has fallen quickly to
below 2,5 bar, and within no more than 4 s after the brake pipe accelerator commences operation, the
brake pipe accelerator shall stop venting air so that the brake pipe can rapidly be refilled. This
requirement shall be proven by testing in accordance with 5.2.4.4.
No functional errors shall occur in the operation of the brake pipe accelerator at input pressures of
(5,00 ± 1,00) bar. This requirement shall be proven by testing in accordance with 5.2.4.10.
4.2.3 Train behaviour
The brake pipe accelerator shall exhaust the air from the brake pipe without causing any adverse effect
on train behaviour. This requirement shall be proven by testing in accordance with 5.3.
4.2.4 Effect of overcharge
4.2.4.1 Overcharge after full service braking
The brake pipe accelerator shall not come into operation due to the effect of a normal working pressure
overcharge after a full service braking, which allows a build-up of brake pipe pressure above normal
working pressure to 6,00 bar. It shall be taken into account that this overcharge can be present for up to
40 s in brake mode “G” and 10 s in brake mode “P” after a full service braking. This requirement shall be
proven by testing in accordance with 5.2.4.8.
4.2.4.2 Overcharge starting from normal working pressure
The brake pipe accelerator shall not come into operation if the brake pipe pressure, starting from the
normal working pressure, is raised to 6,0 bar for 2 s, then is reduced to 5,2 bar in 1 s, followed by a
return to the normal working pressure at a rate of 0,15 bar in 60 s. This requirement shall be proven by
testing in accordance with 5.2.4.9.
7

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SIST EN 15612:2020
EN 15612:2020 (E)
4.2.5 Effect of individual vehicle
The operation of the brake pipe accelerator shall not be affected by an individual vehicle with a brake
pipe volume not exceeding 25 l, where a brake pipe accelerator is not fitted or the brake has been
isolated. This shall apply irrespective of the position of that vehicle in the train consist. This
requirement shall be proven by testing in accordance with 5.3.
4.2.6 Subsequent emergency braking
The brake pipe accelerator shall come into operation when an emergency braking is applied after a full
service braking. This requirement shall be proven by testing in accordance with 5.2.4.7.
4.2.7 Sensitivity
The brake pipe accelerator shall come into operation as response to a drop in brake pipe pressure with
a gradient of 1,80 bar in (3,0 + 0,1) s starting from input pressure of (5,00 ± 0,05) bar with a maximum
delay of 2 s.
This requirement shall be proven by testing in accordance with 5.2.4.4.
4.2.8 Insensitivity to brake pipe pressure fall
The brake pipe accelerator shall not come into operation as response to a drop in brake pipe pressure
with a gradient of 1,80 bar in (6,0 + 0,3) s starting from input pressure of (5,00 ± 0,05) bar. Continuing
the pressure fall down to 2,5 bar shall not cause the brake pipe accelerator to operate. This requirement
shall be proven by testing in accordance with 5.2.4.5.
4.2.9 Insensitivity to distributor valve quick service device operation
The brake pipe accelerator shall not operate during the initial stage of service braking due to operation
of the distributor valve internal quick service device. The initial stage of service braking is characterized
by a drop of the brake pipe pressure starting at (5,00 ± 0,05) bar by (0,50 ± 0,05) bar within 1,0 s, with
the initial rate of 2,0 bar/s during the first pressure drop of (0,30 ± 0,05) bar as shown in Figure 2.
8

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SIST EN 15612:2020
EN 15612:2020 (E)

Key
P pressure, expressed in bar
t time, expressed in s
Figure 2 — Brake pipe pressure fall for insensitivity test
This requirement shall be proven by testing in accordance with 5.2.4.6.
4.2.10 Tightness
Tightness of the brake pipe accelerator shall be such that technical performance as specified by this
document is met without restrictions.
The sealing arrangement within the brake pipe accelerator shall prevent loss of air as follows when
considering a brake pipe pressure of 6,0 bar:
— At an environmental temperature of (20 ± 5) °C, the brake pipe accelerator shall not have a leakage
rate of greater than 0,005 Nl/min. This requirement shall be proven by testing in accordance with
5.2.4.3;
— At –25 °C ≤ environmental temperature < 15 °C, also at 25 °C < environmental temperature ≤ 70 °C,
the brake pipe accelerator shall not have a leakage rate of greater than 0,01 Nl/min. This
requirement shall be proven by testing in accordance with 5.2.5;
— At –40 °C ≤ environmental temperature < –25 °C, the brake pipe accelerator shall not have a
leakage rate of greater than 0,1 Nl/min. This requirement shall be proven by testing in accordance
with 5.2.5.
9

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SIST EN 15612:2020
EN 15612:2020 (E)
4.3 Shock and vibration requirements
The brake pipe accelerator shall be able to operate without restriction under shock and vibration
conditions as specified by EN 61373:2010. The class and category of test severity shall be declared by
design documentation.
These requirements shall be tested in accordance with 5.2.4.11.
4.4 Environment requirements
4.4.1 General
All the environmental requirements listed shall be taken into account within the design concept of the
components. However, only the assessment tests listed in Clause 5 shall be performed. The remaining
proofs shall be presented in the declarations of conformity.
4.4.2 Temperature
Brake pipe accelerators covered by this document shall be able to operate at –40 °C ≤ environmental
temperature ≤ +70 °C without any deviation from the technical requirements specified in Clause 4 of
this document, except the case defined below.
At –40 °C ≤ environmental temperature < –25 °C the brake pipe accelerator shall come into operation as
response to a drop in brake pipe pressure with a gradient of 1,8 bar in (3,0 + 0,1) s starting from input
pressure with no time limit for the delay, defined in 4.2.7.
This requirement shall be proven by testing in accordance with 5.2.5.
4.4.3 Other environmental conditions
4.4.3.1 Altitude
The brake pipe accelerator shall be able to operate without restrictions up to altitude of 2 000 m.
4.4.3.2 Humidity
The following external humidity levels shall be considered:
— yearly average: ≤ 75 % relative humidity;
— on 30 days in the year continuously: between 75 % and 95 % relative humidity;
— on the other days occasionally: between 95 % and 100 % relative humidity;
3
— maximum absolute humidity: 30 g/m occurring in tunnels.
An operationally caused infrequent and slight moisture condensation shall not lead to any malfunction
or failure.
The psychometric charts contained in EN 50125-1:2014 shall be used to establish the range of variation
of the relative humidity for the different temperature classes that it is considered will not be exceeded
for more than 30 days per year.
At cooled surfaces, 100 % relative humidity can occur causing condensation on parts of equipment; this
shall not lead to any malfunction or failure.
Sudden changes of the air temperature with a rate of 3K/s and maximum variation of 40 K local to the
vehicle can cause condensation of water on parts of the equipment. These conditions particularly
occurring when entering or leaving a tunnel shall not lead to any malfunction or failure of the
equipment.
10

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SIST EN 15612:2020
EN 15612:2020 (E)
4.4.3.3 Rain
Rain rate of 6 mm/min shall be taken into account. The effect of rain shall be considered depending on
the possible equipment installation together with wind and vehicle movement.
4.4.3.4 Snow, ice and hail
Consideration shall be given to the effect of all kinds of snow, ice and/or hail. The maximum diameter of
hailstones shall be taken as 15 mm, larger diameters can occur exceptionally. The effect of snow, ice and
hail shall be considered depending on the equipment installation together with wind and vehicle
movement.
4.4.3.5 Solar radiation
2
Equipment design shall allow for direct exposure to solar radiation at the rate of 1 120 W/m for a
maximum duration of 8 h.
4.4.3.6 Pollution
The effects of pollution shall be considered in the design of equipment and components. Means may be
provided to reduce pollution by the effective use of protection of the brake pipe accelerator. The
severity of pollution can depend upon the location of the equipment on the vehicle, therefore the effects
of the kinds of pollution indicated in Table 1 shall be considered as a minimum.
Table 1 — Pollution
Pollution Class to be considered
Chemically active substances Class 5C2 of EN 60721-3–5:1997
Class 5F2 (electrical engine) of EN 60721-3–5:1997
Contaminating fluids
Class 5F3 (thermal engine) of EN 60721-3–5:1997
Biologically active substances Class 5B2 of EN 60721-3–5:1997
Dust Class 5S2 of EN 60721-3–5:1997
Stones and other objects Objects of maximum 15 mm diameter and ballast
Sand Class 5S2 of EN 60721-3–5:1997
Sea spray Class 5C2 of EN 60721-3–5:1997

4.5 Compressed air quality
It shall be possible to operate the brake pipe accelerator without restrictions with at least the
compressed air quality according to the following classes defined by ISO 8573-1:2010:
— class 3 – for the maximum particle size and the maximum concentration of solid contaminants;
— class 4 – for the water dew point;
— class 4 – for the maximum total (droplets, aerosols and vapours) oil concentration.
4.6 Fire behaviour
The fire behaviour of the brake pipe accelerator shall correspond to the requirements of EN 45545-2:
2013+A1:2015.
11

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SIST EN 15612:2020
EN 15612:2020 (E)
4.7 External appearance
The dimensions and the coordinates and threads of the ports and fixing points of the brake pipe
accelerator shall comply with the details given by the relevant drawings.
The design of the brake pipe accelerator shall ensure that the exterior surfaces of the brake pipe
accelerator are free of sharp edges and corners that could be dangerous to those people handling the
brake pipe accelerator or, when installed on a vehicle, working on adjacent equipment.
This requirement shall be checked in accordance with 5.2.4.2.
4.8 Design requirements regarding pressure stress
The design of the brake pipe accelerator shall allow safe required performance with a maximum supply
pressure of 10 bar. It shall be taken into consideration that the maximum supply pressure can be
reached in other pneumatic circuits of the brake pipe accelerator.
4.9 Interfaces
4.9.1 General
A brake pipe accelerator shall be capable of being installed on the vehicle in accordance with 4.9.2 and
4.9.3 or directly mounted to a distributor valve.
4.9.2 Mechanical
The connection of the brake pipe accelerator to the vehicle shall be via a mounting bracket or manifold.
The interface shall be suitably sized to meet the physical loadings identified in this document. The
interface of the brake pipe accelerator depends on the individual design of the brake pipe accelerator`s
design.
4.9.3 Pneumatic
The pneumatic interface with the vehicle pipework shall be via a suitable manifold/pipe connection
such that removal of the brake pipe accelerator without disturbing the main brake pipe is possible. The
pipe connections to the brake pipe shall be via a threaded connection of size G 1 or G 1 1/4 in
accordance with EN ISO 228-1:2003.
5 Type tests
5.1 General
The following type tests shall be carried out:
a) individual brake pipe accelerator tests (see 5.2);
b) simulated train consist tests (see 5.3).
All the test requirements shall be achieved to obtain type test compliance.
The accuracy of the measuring devices shall be declared in the test report and the measurement
uncertainty shall be taken into account by the assessment.
5.2 Individual brake pipe accelerator tests
5.2.1 Test bench for individual brak
...

SLOVENSKI STANDARD
oSIST prEN 15612:2018
01-december-2018
Železniške naprave - Zavore - Pospešilnik praznjenja glavnega zavornega voda
Railway applications - Braking - Brake pipe accelerator valve
Bahnanwendungen - Bremse - Schnellbremsbeschleunigungsventil
Applications ferroviaires - Freinage - Valve accélératrice de vidange
Ta slovenski standard je istoveten z: prEN 15612
ICS:
45.040 Materiali in deli za železniško Materials and components
tehniko for railway engineering
oSIST prEN 15612:2018 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN 15612:2018

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oSIST prEN 15612:2018


DRAFT
EUROPEAN STANDARD
prEN 15612
NORME EUROPÉENNE

EUROPÄISCHE NORM

October 2018
ICS 45.040 Will supersede EN 15612:2008+A1:2010
English Version

Railway applications - Braking - Brake pipe accelerator
valve
Applications ferroviaires - Freinage - Valve Bahnanwendungen - Bremse -
accélératrice de vidange Schnellbremsbeschleunigungsventil
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 256.

If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations
which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.

This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC
Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and United Kingdom.

Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.

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


EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2018 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 15612:2018 E
worldwide for CEN national Members.

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oSIST prEN 15612:2018
prEN 15612:2018 (E)
Contents Page
European foreword . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Design and manufacture . 6
4.1 General . 6
4.2 Functional requirements. 7
4.2.1 General . 7
4.2.2 Operating requirements . 7
4.2.3 Train/vehicle behaviour . 7
4.2.4 Affect of overcharge . 7
4.2.5 Affect of individual vehicle . 7
4.2.6 Subsequent emergency application . 7
4.2.7 Sensitivity . 8
4.2.8 Insensitivity of brake pipe pressure fall . 8
4.2.9 Insensitivity to distributor valve quick service device operation . 8
4.2.10 Isolation . 8
4.2.11 Leakage . 8
4.3 Vibration and shocks requirements . 8
4.4 Environment requirements . 9
4.4.1 General . 9
4.4.2 Temperature . 9
4.4.3 Other environmental conditions . 9
4.5 Compressed air quality . 11
4.6 Service life . 11
4.7 Fire behaviour . 11
4.8 External appearance . 11
4.9 Design requirements regarding pressure stress . 12
4.10 Interfaces . 12
4.10.1 General . 12
4.10.2 Mechanical . 12
4.10.3 Pneumatic . 12
5 Materials . 12
6 Type tests . 12
6.1 General . 12
6.2 Individual brake pipe accelerator tests . 12
6.2.1 Test bench for individual brake pipe accelerator tests . 12
6.2.2 Sampling for type tests . 14
6.2.3 Test temperature and air quality . 14
6.2.4 Procedure for type tests . 14
6.2.5 Operation at extreme temperatures . 17
6.3 Simulated train consist tests . 18
6.3.1 Simulated train consist test bench . 18
6.3.2 Sampling for train consist test . 19
6.3.3 Test temperature and air quality . 19
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6.3.4 Test procedure . 19
7 Routine test and inspection . 20
8 Documentation . 20
9 Designation . 20
10 Identification and marking . 21
Annex ZA (informative) Relationship between this European Standard and the Essential
Requirements of EU Directive 2008/57/EC aimed to be covered. 22
Bibliography . 24

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European foreword
This document (prEN 15612:2018) has been prepared by Technical Committee CEN/TC 256 “Railway
applications”, the secretariat of which is held by DIN.
This document is currently submitted to the CEN Enquiry.
This document will supersede EN 15612:2008+A1:2010.
This document has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association, and supports essential requirements of EU Directive 2008/57/EC.
For relationship with EU Directive 2008/57/EC, see informative Annex ZA, which is an integral part of
this document.
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1 Scope
This document is applicable to brake pipe accelerator valves designed to vent the brake pipe of railway
vehicles when an emergency brake application is initiated, without taking the type of vehicles and track-
gauge into consideration.
This document specifies the requirements for the design, manufacture and testing of brake pipe
accelerator valves.
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 14478, Railway applications – Braking – Generic vocabulary
EN 14601, Railway applications – Straight and angled end cocks for brake pipe and main reservoir pipe
EN 15355, Railway applications – Braking – Distributor valves and distributor-isolating devices
EN 50125-1, Railway applications – Environmental conditions for equipment – Part 1: Rolling stock and on-
board equipment
EN 60721-3-5:1997, Classification of environmental conditions – Part 3: Classification of groups of
environmental parameters and their severities – Section 5: Ground vehicle installations (IEC 60721-3-
5:1997)
EN 61373:2010, Railway applications – Rolling stock equipment – Shock and vibration tests
(IEC 61373:2010)
EN ISO 228-1, Pipe threads where pressure-tight joints are not made on the threads – Part 1: Dimensions,
tolerances and designation (ISO 228-1)
ISO 8573-1:2010, Compressed air – Part 1: Contaminants and purity classes
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 14478 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at http://www.iso.org/obp
3.1
brake pipe accelerator valve
device connected to the brake pipe of a vehicle, which operates in response to seeing a rapid fall in brake
pipe pressure to ensure a continuing rapid fall to below 2,5 bar
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3.2
brake mode “good”
brake mode “freight”
brake mode “G”
brake mode characterized by slow brake application and release times specific for distributor valves used
on freight trains for slow speed
3.3
brake mode “passenger”
brake mode “P”
brake mode characterized by fast brake application and release times specific for distributor valves used
on trains for passenger traffic
3.4
normal litre
NI
unit of mass for gases equal to the mass of 1 l at a pressure of 1,013 2 bar (one atmosphere) and at a
standard temperature, often 0 °C or 20 °C
Note 1 to entry: Airflow is often stated in normal litres per minute (NI/min).
3.5
operating pressure
reference input pressure in full release position
Note 1 to entry: This is normally 5 bar brake pipe pressure but can be 4 bar or 6 bar.
3.6
quick service function
function of a distributor valve which allows, when applying the brake from stand-by and released
position, the local fast venting of brake pipe pressure by a certain specified amount and at a certain
specified gradient, to provide pneumatic brake signal transmission through a train
3.7
quick service device
device that fulfils the quick service function
3.8
emergency brake application
brake pipe pressure fall seen at the accelerator valve as a result of a demand for an emergency brake
application from any source
3.9
overcharge
increase in brake pipe pressure above normal operating pressure
4 Design and manufacture
4.1 General
The design and manufacture of the brake pipe accelerator valves shall take the requirements of this
standard into account for all intended operating conditions.
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4.2 Functional requirements
4.2.1 General
Brake pipe accelerator valves shall be able to operate with all interoperable distributors and existing
interoperable brake pipe accelerator valves.
The brake pipe accelerator valve shall be ready to operate when the brake pipe has reached its operating
(running) pressure. The brake pipe accelerator valve shall operate in response to a defined rapid fall of
brake pipe pressure to ensure a continuing rapid fall to below 2,5 bar.
4.2.2 Operating requirements
The following operating requirements are defined in relation to a 5 bar brake pipe operating (running)
pressure. When an emergency brake application occurs, the brake pipe accelerator valves shall create a
sufficiently rapid reduction in brake pipe pressure to ensure the rapid increase in brake cylinder pressure
on every vehicle in the train set. When the pressure in the brake pipe has fallen quickly to below 2,5 bar,
and within no more than 4 s after the brake pipe accelerator valve commences operation, the brake pipe
accelerator valve shall stop venting air in such a way that the brake pipe can rapidly be refilled. This
requirement shall be proven by testing in accordance with 6.2.4.4.
No functional errors shall occur in the operation of the brake pipe accelerator valve at operating
(running) pressures of (5 ± 1) bar. This requirement shall be proven by testing in accordance with
6.2.4.10.
4.2.3 Train/vehicle behaviour
The brake pipe accelerator valve shall exhaust the air from the brake pipe without causing any adverse
effect on vehicle/train behaviour. This requirement shall be proven by testing in accordance with 6.3.
4.2.4 Affect of overcharge
4.2.4.1 Overcharge after full service application
The brake pipe accelerator valve shall not come into operation due to the effect of an operating pressure
overcharge after a full service brake application, which allows a build-up of brake pipe pressure above
normal operating pressure to 6 bar. It shall be taken into account that this overcharge can be present for
up to 40 s in brake mode “G” and 10 s in brake mode “P” after a full service application. This requirement
shall be proven by testing in accordance with 6.2.4.8.
4.2.4.2 Overcharge starting from operating pressure
The brake pipe accelerator valve shall not come into operation if the brake pipe pressure, starting from
the operating pressure, is raised to 6 bar for 2 s, then is reduced to 5,2 bar in 1 s, followed by a return to
the operating pressure at a rate of 0,15 bar in 60 s. This requirement shall be proven by testing in
accordance with 6.2.4.9.
4.2.5 Affect of individual vehicle
The operation of the brake pipe accelerator valve shall not be affected by an individual vehicle with a
brake pipe volume not exceeding 25 l, where a brake pipe accelerator valve is not fitted or the brake has
been isolated. This shall apply irrespective of the position of that vehicle in the train consist. This
requirement shall be proven by testing in accordance with 6.3.
4.2.6 Subsequent emergency application
The brake pipe accelerator valve shall come into operation when an emergency brake application is made
after a full service brake application. This requirement shall be proven by testing in accordance with
6.2.4.7.
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4.2.7 Sensitivity
The brake pipe accelerator valve shall come into operation no later than 2 s after the pressure in the
brake pipe, venting to atmosphere, has fallen from 5 bar to 3,2 bar within 3 s. This requirement shall be
proven by testing in accordance with 6.2.4.4.
4.2.8 Insensitivity of brake pipe pressure fall
The brake pipe accelerator valve shall not come into operation when the pressure in the brake pipe falls
uniformly from 5 bar to 3,2 bar over 6 s with the distributor inoperative. Continuing the pressure fall
down to 2,5 bar shall not cause the brake pipe accelerator valve to operate. This requirement shall be
proven by testing in accordance with 6.2.4.5.
4.2.9 Insensitivity to distributor valve quick service device operation
The brake pipe accelerator valve shall not operate during the initial stage of service braking due to
operation of the distributor valve internal quick service device. This requirement shall be proven by
testing in accordance with 6.2.4.6.
4.2.10 Isolation
4.2.10.1 If the brake pipe accelerator valve is incorporated in the distributor, it shall be inoperative
after the distributor has been isolated. This requirement shall be proven by testing in accordance with
EN 15355 as part of the distributor valve test.
4.2.10.2 If the brake pipe accelerator valve is fitted separately from the distributor it shall be possible
to isolate the brake pipe accelerator valve from the brake pipe and vent its pressure, using a suitable
valve or device in the pipework such that it can be sealed in the normal open position with the isolating
handle in the vertical down position.
NOTE This requirement will be specified in the relevant system standard.
4.2.11 Leakage
Leakage of the brake pipe accelerator valve shall be such that technical performance as specified by this
standard is met without restrictions.
The sealing arrangement within the brake pipe accelerator valve shall prevent loss of air as follows when
considering a brake pipe operating pressure of 6 bar:
— At an environmental temperature of (20 ± 5) °C, the brake pipe accelerator valve shall not have a
leakage rate of greater than 0,005 Nl/min. This requirement shall be proven by testing in accordance
with 6.2.4.3;
— At – 25 °C ≤ environmental temperature < 15 °C, also at 25 °C < environmental temperature ≤ 70 °C,
the brake pipe accelerator valve shall not have a leakage rate of greater than 0,01 Nl/min at the
normal working pressures. This requirement shall be proven by testing in accordance with 6.2.5;
— At – 40 °C ≤ environmental temperature < – 25 °C, the brake pipe accelerator valve shall not have a
leakage rate of greater than 0,1 Nl/min at normal working pressures. This requirement shall be
proven by testing in accordance with 6.2.5.
4.3 Vibration and shocks requirements
The brake pipe accelerator valve shall be able to operate without restriction under vibration and shock
conditions as specified by EN 61373:2010, Category 1, Class A or B. This requirement shall be proven by
testing in accordance with 6.2.4.11.
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4.4 Environment requirements
4.4.1 General
The design shall take into account that the brake pipe accelerator valve shall be able to be put into service
and operate normally in the conditions and climatic zones for which it is intended to operate and in which
it is likely to run, as specified in this standard.
NOTE 1 The environmental conditions are expressed in classes for temperature, humidity, etc. thereby giving
the vehicle designer the choice of a brake pipe accelerator valve suitable for operation on a vehicle all over Europe,
or have a restricted use.
NOTE 2 The environment range limits specified are those that have a low probability of being exceeded. All
specified values are maximum or limit values. These values can be reached, but do not occur permanently.
Depending on the situation there can be different frequencies of occurrence related to a certain period of time.
NOTE 3 The environment requirements of this document cover the environment requirements of the HS RST TSI
which only refers to EN 50125-1.
The brake pipe accelerator valve shall be tested in accordance with requirements given in Clause 6 of this
standard including where required environmental/climatic testing.
4.4.2 Temperature
Brake pipe accelerator valves covered by this standard shall be able to operate
— at – 25 °C ≤ environmental temperature ≤ 70 °C, without any deviation from the technical
requirements specified in Clause 4 in this standard,
— at – 40 °C ≤ environmental temperature < – 25 °C, with allowed deviation from the technical
requirements specified in this standard but without affecting the function of the brake pipe
accelerator valve.
Deviations from the technical requirements when testing at extremes are defined in 6.2.5.
The purchaser can specify higher or lower extreme temperature limit values if operational constraints
demand it. In this case the temperature limit values used in the extreme temperature tests in 6.2.5 shall
be changed accordingly.
4.4.3 Other environmental conditions
4.4.3.1 General
The following environmental conditions shall be considered in the design of the brake pipe accelerator
valve.
It shall be demonstrated that these environmental conditions have been taken into account in the design
of the brake pipe accelerator valve. It is sufficient for the supplier to make a declaration of conformity
stating how the environmental conditions in the following clauses have been taken into account.
If not specifically required to be tested as part of the type testing requirements in Clause 6 of this
standard, suitable tests and/or design assessments considering the effect of the following environmental
conditions on the brake pipe accelerator valve, shall be used in the development/design proving of the
brake pipe accelerator valve, prior to type testing.
4.4.3.2 Altitude
The brake pipe accelerator valve shall be able to operate without restrictions up to altitude of 2 000 m.
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4.4.3.3 Humidity
The following external humidity levels shall be considered:
— yearly average: ≤ 75 % relative humidity;
— on 30 days in the year continuously: between 75 % and 95 % relative humidity;
— on the other days occasionally: between 95 % and 100 % relative humidity;
3
— maximum absolute humidity: 30 g/m occurring in tunnels.
An operationally caused infrequent and slight moisture condensation shall not lead to any malfunction
or failure.
The psychometric charts contained in EN 50125-1 shall be used to establish the range of variation of the
relative humidity for the different temperature classes that it is considered will not be exceeded for more
than 30 d per year.
At cooled surfaces, 100 % relative humidity can occur causing condensation on parts of equipment; this
shall not lead to any malfunction or failure.
Sudden changes of the air temperature local to the vehicle can cause condensation of water on parts of
equipment with rate of 3 K/s and maximum variation of 40 K; these conditions particularly occurring
when entering or leaving a tunnel shall not lead to any malfunction or failure of the equipment.
4.4.3.4 Rain
Rain rate of 6 mm/min shall be taken into account. The effect of rain shall be considered depending on
the possible equipment installation together with wind and vehicle movement.
4.4.3.5 Snow, ice and hail
Consideration shall be given to the effect of all kinds of snow, ice and/or hail. The maximum diameter of
hailstones shall be taken as 15 mm, larger diameters can occur exceptionally. The effect of snow, ice and
hail shall be considered depending on the equipment installation together with wind and vehicle
movement.
4.4.3.6 Solar radiation
2
Equipment design shall allow for direct exposure to solar radiation at the rate of 1 120 W/m for a
maximum duration of 8 h.
4.4.3.7 Pollution
The effects of pollution shall be considered in the design of equipment and components. Means may be
provided to reduce pollution by the effective use of protection of the brake pipe accelerator valve. The
severity of pollution can depend upon the location of the equipment on the vehicle, therefore the effects
of the kinds of pollution indicated in Table 1 shall be considered as a minimum.
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Table 1 — Pollution
Pollution Class to be considered
Chemically active substances Class 5C2 of EN 60721-3-5:1997
Class 5F2 (electrical engine) of EN 60721-3-5:1997
Contaminating fluids
Class 5F3 (thermal engine) of EN 60721-3-5:1997
Biologically active substances Class 5B2 of EN 60721-3-5:1997
Dust Class 5S2 of EN 60721-3-5:1997
Stones and other objects Ballast and other objects of maximum 15 mm diameter
Sand Class 5S2 of EN 60721-3-5:1997
Sea spray Class 5C2 of EN 60721-3-5:1997
4.5 Compressed air quality
It shall be possible to operate the brake pipe accelerator valve without restrictions with at least the
compressed air quality according to the following classes defined by ISO 8573-1:2010:
— class 4 – for the maximum particle size and the maximum concentration of solid contaminants;
— class 4 – for the water dew point;
— class 4 – for the maximum total (droplets, aerosols and vapours) oil concentration.
The brake pipe accelerator valve shall be capable of operating in an air supply system that is not fitted
with an air dryer, or when the air dryer is out of order. The air system should therefore include some
means of preventing water collecting within the brake pipe accelerator valve and hence freezing of the
water in conditions below 0 °C.
4.6 Service life
No specific requirements for the brake pipe accelerator valve to attain a particular service life are
contained in this standard.
Any testing to establish the service life of a brake pipe accelerator valve shall
...

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