SIST EN 15625:2021

Railway applications - Braking - Automatic variable load sensing devices

This document applies variable load sensing devices designated to continuously sense the load of a railway vehicle and provide a signal that can be used by a relay valve for the automatic variation of the air pressure used for brake applications, thereby adjusting the brake force accordingly to achieve the required brake performance.
This document specifies the requirements for the design, dimensions, manufacture and testing of automatic variable load sensing devices.

Bahnanwendungen - Bremse - Automatisch kontinuierlich wirkende Lasterfassungseinrichtungen

Dieses Dokument gilt für automatisch kontinuierlich wirkende Lasterfassungseinrichtungen (Wiegeventile), die so beschaffen sind, dass sie die Last eines Eisenbahnfahrzeuges kontinuierlich erfassen und ein Signal erzeugen, das von einem Relaisventil für die automatische Anpassung des für eine Bremsbetätigung verwendeten pneumatischen Drucks benutzt wird, wodurch die Bremskraft zur Erzielung der geforderten Bremsleistung entsprechend angepasst werden kann.
In diesem Dokument werden die Anforderungen an die Konstruktion, die Abmessungen, die Herstellung und Prüfung von Wiegeventilen festgelegt.

Applications ferroviaires - Freinage - Dispositifs de pesée variable automatiques

Le présent document s’applique aux dispositifs de pesée destinés à détecter en continu la charge d’un véhicule ferroviaire et à fournir un signal utilisable par un relais pneumatique pour ajuster de façon automatique la pression d’air utilisée pour le freinage, ajustant ainsi l’effort de freinage en conséquence pour obtenir les performances de freinage requises.
Le présent document spécifie les exigences relatives à la conception, aux dimensions, à la fabrication et aux essais des dispositifs de pesée.

Železniške naprave - Zavore - Naprave za samodejno zaznavanje spremembe obtežbe

General Information

• Status: Published
• Public Enquiry End Date: 31-Mar-2019
• Publication Date: 21-Feb-2021
• ICS: 45.040 - Materials and components for railway engineering
• Technical Committee: IŽNP - Reilway applications
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 18-Feb-2021
• Due Date: 25-Apr-2021
• Completion Date: 22-Feb-2021
• Directive: 2008/57/EC - Directive 2008/57/EC of the European Parliament and of the Council of 17 June 2008 on the interoperability of the rail system within the Community (Recast)
• Mandate: M/483 - Mandate for programming and standardisation addressed to the European standardisation bodies under directive 2008/57/EC in the field of the interoperability of the rail system within the European Union
• Ref Project: EN 15625:2021 - Railway applications - Braking - Automatic variable load sensing devices

RELATIONS

• Revised: SIST EN 15625:2009+A1:2011 - Railway applications - Braking - Automatic variable load sensing devices
• Effective Date: 15-Jul-2018
• Replaces: SIST EN 15625:2009+A1:2011 - Railway applications - Braking - Automatic variable load sensing devices
• Effective Date: 17-Feb-2021

Standards Content (sample)

SLOVENSKI STANDARD
SIST EN 15625:2021
01-april-2021
Nadomešča:
SIST EN 15625:2009+A1:2011
Železniške naprave - Zavore - Naprave za samodejno zaznavanje spremembe
obtežbe
Railway applications - Braking - Automatic variable load sensing devices
Bahnanwendungen - Bremse - Automatisch kontinuierlich wirkende
Lasterfassungseinrichtungen

Applications ferroviaires - Freinage - Dispositifs de pesée variable automatiques

Ta slovenski standard je istoveten z: EN 15625:2021
ICS:
45.040 Materiali in deli za železniško Materials and components
tehniko for railway engineering
SIST EN 15625:2021 en,fr,de

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

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SIST EN 15625:2021
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SIST EN 15625:2021
EN 15625
EUROPEAN STANDARD
NORME EUROPÉENNE
February 2021
EUROPÄISCHE NORM
ICS 45.040 Supersedes EN 15625:2008+A1:2010
English Version
Railway applications - Braking - Automatic variable load
sensing devices

Applications ferroviaires - Freinage - Dispositifs de Bahnanwendungen - Bremse - Automatisch

pesée variable automatiques kontinuierlich wirkende Lasterfassungseinrichtungen
This European Standard was approved by CEN on 20 December 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

© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 15625:2021 E

worldwide for CEN national Members.
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SIST EN 15625:2021
EN 15625:2021 (E)
Contents Page

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

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

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

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

4 Symbols and abbreviations ......................................................................................................................... 7

5 Design and manufacture ............................................................................................................................... 7

5.1 General ................................................................................................................................................................ 7

5.2 Functional requirements.............................................................................................................................. 7

5.2.1 Operating requirements ............................................................................................................................... 7

5.2.2 Characteristics of weighing valves ............................................................................................................ 7

5.2.3 Mechanical requirements ............................................................................................................................ 8

5.2.4 Tightness ............................................................................................................................................................ 8

5.3 Fire behaviour .................................................................................................................................................. 8

5.4 Shock and vibration ....................................................................................................................................... 9

5.5 Service life .......................................................................................................................................................... 9

5.6 Compressed air quality ................................................................................................................................. 9

5.7 Environmental conditions ........................................................................................................................... 9

5.7.1 General ................................................................................................................................................................ 9

5.7.2 Ambient temperature .................................................................................................................................... 9

5.7.3 Altitude ............................................................................................................................................................... 9

5.7.4 Humidity .......................................................................................................................................................... 10

5.7.5 Rain ................................................................................................................................................................... 10

5.7.6 Snow, ice and hail ......................................................................................................................................... 10

5.7.7 Solar radiation .............................................................................................................................................. 10

5.7.8 Pollution .......................................................................................................................................................... 10

5.8 External appearance ................................................................................................................................... 11

5.9 Design requirements regarding pressure stress .............................................................................. 11

5.10 Pneumatic connections .............................................................................................................................. 11

6 Type tests ........................................................................................................................................................ 11

6.1 General ............................................................................................................................................................. 11

6.2 Individual automatic variable load sensing device type tests ..................................................... 12

6.2.1 Test bench for individual automatic variable load sensing devices type tests ..................... 12

6.2.2 Sampling for type test ................................................................................................................................. 13

6.2.3 Test requirements ....................................................................................................................................... 13

6.2.4 Check of physical and geometrical characteristics .......................................................................... 14

6.2.5 Tightness ......................................................................................................................................................... 14

6.2.6 Characteristic, hysteresis .......................................................................................................................... 15

6.2.7 Operation at extreme temperature ....................................................................................................... 16

6.2.8 Shock and vibration tests .......................................................................................................................... 18

7 In-service assessment................................................................................................................................. 19

8 Designation..................................................................................................................................................... 19

9 Identification and marking ....................................................................................................................... 19

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EN 15625:2021 (E)

Annex A (informative) Assessment of an automatic variable load sensing device when

fitted to a vehicle ........................................................................................................................................... 21

A.1 General ............................................................................................................................................................. 21

A.2 Design acceptance testing set up ............................................................................................................ 21

A.3 Running tests .................................................................................................................................................. 21

A.3.1 General ............................................................................................................................................................. 21

A.3.2 Pneumatic automatic variable load sensing device – Air consumption ................................... 21

A.3.2.1 Procedure ........................................................................................................................................................ 21

A.3.2.2 Pass/fail criteria ........................................................................................................................................... 21

A.3.3 Automatic variable load sensing device – Output signal variation ............................................ 22

A.3.3.1 Procedure ........................................................................................................................................................ 22

A.3.3.2 Pass/fail criteria ........................................................................................................................................... 22

Annex B (normative) In-service assessment ................................................................................................... 23

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

Requirements of EU Directive 2016/797/EU aimed to be covered............................................ 24

Bibliography ................................................................................................................................................................. 26

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SIST EN 15625:2021
EN 15625:2021 (E)
European foreword

This document (EN 15625:2021) 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 August 2021, and conflicting national standards shall be

withdrawn at the latest by August 2021.

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 15625:2008+A1:2010.
The main changes compared to EN 15625:2008+A1:2010 are:
a) normative references have been updated;
b) terms and definitions have been revised;
c) requirements on design and manufacture have been revised;
d) requirements on materials have been removed;
e) requirements on type tests have been revised;
f) requirements on routine test and inspection have been removed;
g) requirements on type validation have been removed;
h) requirements on in-service assessment have been added;
i) requirements on documentation have been removed;
j) requirements on designation, identification and marking have been revised;
k) Annex ZA has been updated.

This document has been prepared under a standardization request given to CEN by the European

Commission and the European Free Trade Association, and supports essential requirements of

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.
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SIST EN 15625:2021
EN 15625:2021 (E)
1 Scope

This document applies to automatic variable load sensing devices designed to continuously sense the

load of a railway vehicle and provide a pneumatic output signal that can be used by a relay valve for the

automatic variation of the air pressure used for brake applications, thereby adjusting the brake force

accordingly to achieve the required brake performance.

This document specifies the requirements for the design, testing and quality assurance of automatic

variable load sensing devices.

The requirements of this document are not fully applicable for tests on vehicle level (vehicle

homologation tests).
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 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 45545-2:2020, Railway applications — Fire protection on railway vehicles — Part 2: Requirements for

fire behavior of materials and components

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
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
3.1
automatic variable load sensing device
weighing valve

device connected to the vehicle, which responds to the loading of that vehicle to provide a continuous

load proportional signal to the brake control device

Note 1 to entry: The load input is normally a share of the wagon’s mass because of the devices position in the

vehicle suspension system. The result is a pneumatic output signal pressure that can be any value between a

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EN 15625:2021 (E)

minimum at tare mass and a maximum at maximum mass. Most of the existing self-adjusting load-dependant brakes

generate the load signal using a weighing valve.
3.2
mechanically operated pneumatic device

device or mechanism which responds to a mechanical input by a change of the output pressure

3.3
hydraulic to pneumatic converter

device or mechanism which transforms a hydraulic pressure into a pneumatic pressure with a defined

transmission ratio
3.4
elastomeric to pneumatic converter

device or mechanism having both elastomeric and pneumatic components, which transforms a pressure

in the elastomer into a pneumatic pressure with a defined transmission ratio
3.5
load control pressure
LCP

output pressure delivered by the automatic variable load sensing device, which signals the load of the

vehicle to the brake control device
3.6
supply pressure
input pressure from the air supply to the pneumatic variable load sensing device

Note 1 to entry: Typically supplied from the vehicle's auxiliary reservoir or from the output pressure/brake

cylinder pressure.
3.7
normal litre

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: Air flow is often stated in normal litres per minute (Nl/min).
3.8
sensitivity

minimum change of load which causes a variation of the LCP, when the change of load (input) is in the

same direction
3.9
hysteresis

difference in LCP for the same load, which is first rising to a given value and then, having exceeded that

value, subsequently falls to the same value
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EN 15625:2021 (E)
4 Symbols and abbreviations

F mechanical force, generated by the share of vehicle mass acting at the automatic variable load

sensing device, expressed in kN
LCP load control pressure, expressed in bar
LCP_r measured value of LCP, expressed in bar
LCP_n nominal value of LCP, expressed in bar
5 Design and manufacture
5.1 General

The design and manufacture of the automatic variable load sensing device shall, for all intended operating

conditions, take into account the following requirements.
5.2 Functional requirements
5.2.1 Operating requirements

The automatic variable load sensing device shall, in all cases, supply a pneumatic LCP which is a function

of the load. The transmission of this load signal to the brake control system shall be pneumatic.

The method of producing the pneumatic signal LCP can be mechanically operated pneumatic device, a

hydraulic to pneumatic converter or an elastomeric to pneumatic converter.

Figure 1 indicates the principles of operation of an automatic variable load sensing device.

Key
1 automatic variable load sensing device
2 F, mechanical force, generated by a share of the vehicle mass
3 supply pressure, typically taken from the vehicle’s auxiliary reservoir
4 LCP
Figure 1 — Principles of operation of the automatic variable load sensing device
5.2.2 Characteristics of weighing valves
Three characteristics of weighing valves are defined:
— type 1: (0,8 ± 0,1) bar/10 kN;
— type 2: (0,88 ± 0,1) bar/10 kN;
— type 3: (1,0 ± 0,1) bar/10 kN.
These types are for new interoperable freight wagons.
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EN 15625:2021 (E)
The characteristics of the types shall be tested in accordance with 6.2.6.
The example of characteristics with tolerances is shown in Figure 2.
Key
1 characteristic (nominal value)
2 upper limit of tolerance
3 lower limit of tolerance
Figure 2 — Characteristic of the automatic variable load sensing device
5.2.3 Mechanical requirements

The automatic variable load sensing device shall be designed for a static force F of at least 60 kN. The

maximum force shall not cause any damage or change of its characteristic. This shall be tested in

accordance with 6.2.6.1.
5.2.4 Tightness

Leakage of the automatic variable load sensing device shall be such that technical performance as

specified by this document is met without restrictions.

The sealing arrangement within the automatic variable load sensing device shall prevent any

unacceptable loss of air.

At an environmental temperature of (20 ± 5) °C, the automatic variable load sensing device shall not have

a leakage rate greater than 0,005 Nl/min when tested at a pressure of (7,0 ± 0,1) bar. This requirement

shall be tested in accordance with 6.2.5.

At an environmental temperature of –25 °C, also at +70 °C, the automatic variable load sensing device

shall not have a leakage rate greater than 0,01 Nl/min when tested at a pressure of (7,0 ± 0,1) bar. This

requirement shall be tested in accordance with 6.2.7.

At –40 °C ≤ environmental temperature < –25 °C an automatic variable load sensing device shall have a

leakage rate not greater than 0,1 Nl/min when tested at a pressure of (7,0 ± 0,1) bar in accordance with

6.2.7.
5.3 Fire behaviour

The fire behaviour of the automatic variable load sensing device shall correspond to the requirements of

EN 45545-2:2020.
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5.4 Shock and vibration

The design of the automatic variable load sensing device shall consider outside influences, e.g. impacts

and vibrations, and protect the device appropriately.

The automatic variable load sensing device shall be able to operate without restriction under shock and

vibration conditions as specified in EN 61373:2010. The class and category of test severity shall be

declared by design documentation.
These requirements shall be tested in accordance with 6.2.8.
5.5 Service life

No specific requirements for the automatic variable load sensing device to attain a particular service life

are contained in this document.

Any testing to estimate the service life of an automatic variable load sensing device should be conducted

as part of the product development.

NOTE The service life of the automatic variable load sensing device is a function of the environment/operating

conditions in which the automatic variable load sensing device will function, and the requirements for the automatic

variable load sensing device to achieve a serviceable life in accordance with the maintenance requirements of the

vehicle to which it is fitted.
5.6 Compressed air quality

It shall be possible to operate the automatic variable load sensing device without restrictions with at least

the compressed air quality in accordance with the following classes defined in 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.

The automatic variable load sensing device 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 automatic variable load sensing device and hence

freezing of the water in conditions below 0 °C.
5.7 Environmental conditions
5.7.1 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 6 shall be performed. The remaining

proofs shall be presented in the declarations of conformity.
5.7.2 Ambient temperature

The automatic variable load sensing device covered by this document shall be able to operate from –40 °C

to +70 °C in accordance with the requirements of this document.
5.7.3 Altitude

The automatic variable load sensing device shall be able to operate without restrictions up to an altitude

of 2 000 m above sea level.
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5.7.4 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;
— 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.

At cooled surfaces, 100 % relative humidity can occur, causing condensation on parts of equipment; this

shall not lead to any malfunction or failure.

Sudden lowering of the air temperature local to the vehicle may cause condensation of water on parts of

equipment with rate of 3 K/s and maximum fall in temperature of 40 K.

These conditions particularly occurring when entering or leaving a tunnel shall not lead to any

malfunction or failure of the equipment.
5.7.5 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.
5.7.6 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, exceptionally, larger diameters can occur.

The effect of snow, ice and hail shall be considered depending on the equipment installation together with

wind and vehicle movement.
5.7.7 Solar radiation

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.
5.7.8 Pollution

The effects of pollution shall be considered in the design of equipment and components. The severity of

pollution will depend upon the location of the equipment. Means may be provided to reduce the effect of

pollution. The effects of the following kinds of pollution shall be considered as given in Table 1.

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SIST EN 15625:2021
EN 15625:2021 (E)
Table 1 — Pollution requirements
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
Automatic variable load-sensing device
shall be designed so as to prevent intrusion
For the design of ventilation ducts
of grasses and leaves, pollen, flying insects,
fibres etc.
Sand Class 5S2 of EN 60721-3-5:1997
Sea spray Class 5C2 of EN 60721-3-5:1997
5.8 External appearance

The dimensions and the coordinates and threads of the ports and fixing points of the automatic variable

load sensing device shall comply with the details given by the relevant drawing.

The design of the automatic variable load sensing device shall ensure that the exterior surfaces of the

automatic variable load sensing device are free of sharp edges and corners that could be dangerous to

those people handling the automatic variable load sensing device or, when installed on a vehicle, working

on adjacent equipment.
This requirement shall be checked in accordance with 6.2.4.
5.9 Design requirements regarding pressure stress

The automatic variable load sensing device shall be able to withstand a supply pressure of (7,0 ± 0,1) bar

where applicable.
5.10 Pneumatic connections

The pipe connection threads of the automatic variable load sensing device for the supply pressure and

the LCP shall be G 1/4 in accordance with EN ISO 228-1:2003.
6 Type tests
6.1 General
The tests shall be performed by a competent laboratory.
NOTE As an example, a test institute in accordance with EN ISO/IEC 17025.

The following type tests shall be carried out in order to assess the performance of the automatic variable

load sensing device against the requirements of this document.

The type tests shall be conducted and the records shall be kept as evidence of the compliance with this

document.

The type tests shall be conducted on individual automatic variable load sensing devices.

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EN 15625:2021 (E)
All the test requirements shall be achieved to obtain type test compliance.

Annex A contains tests that can be conducted as part of the type examination of a new automatic variable

load sensing device type.
6.2 Individual automatic variable load sensing device type tests

6.2.1 Test bench for individual automatic variable load sensing devices type tests

The type tests shall be performed on a test bench designed so that all the requirements given by this

document for the testing of the automatic variable load sensing device can be performed.

The dimensions and o
...