EN 1804-2:2020

Machines for underground mines - Safety requirements for hydraulic powered roof supports - Part 2: Power set legs and rams

This document stipulates the safety requirements for use of legs and rams as intended by the manufacturer. These include legs, support rams and rams, including the mechanical extensions, the inner valves and safety devices, seals, the hydraulic connections (up to the 1st hose line or to the valve of design B, see EN 1804-3:2020) and their lifting points, but excluding protective pipes and gaiters, external valves and hydraulic and electrohydraulic control systems.
NOTE   Some components are discussed in other parts of this standard series.
This document applies for legs, support rams, and cylinders that are used at ambient temperatures between -10 °C and 60 °C.
This document identifies and takes account of:
-   possible hazards which may be caused by the operation of legs, support rams and rams;
-   the hazardous areas and the operating conditions that can cause any type of hazard;
-   the situations that can result in hazards that cause an injury or impair health;
-   dangers that can be caused through mine gas and/or flammable dusts.
This document describes methods for reducing these hazards.
Clause 4 contains a list of the hazards discussed.
This document does not specify any additional requirements for:
-   specially corrosive environments;
-   risks associated with manufacturing and decommissioning;
-   earthquake.
A complete hydraulic powered roof support consists of the support units (EN 1804-1:2020), legs and support rams (EN 1804-2:2020) and the hydraulic and electro hydraulic controls (EN 1804-3:2020). Each part of this multipart document addresses the safety requirements of the components mentioned in the scopes of the respective parts of this multipart series.
This document is not applicable to legs and rams manufactured before the date of its publication.

Maschinen für den Bergbau unter Tage - Sicherheitsanforderungen für hydraulischen Schreitausbau - Teil 2: Stempel und Zylinder

Dieses Dokument legt die Sicherheitsanforderungen für die vom Hersteller vorgesehene bestimmungsgemäße Verwendung von Stempeln und Zylindern fest. Hierzu gehören Stempel, Stützzylinder und Zylinder einschließlich der mechanischen Verlängerungen, der inneren Ventile und Sicherheitseinrichtungen, der Dichtungselemente, der hydraulischen Anschlüsse (bis zur 1. Schlauchleitung oder zum Ventil der Bauart B, siehe EN 1804 3:2020) und der Hebepunkte, jedoch ausschließlich der Schutzrohre und -hüllen, der externen Ventile, der hydraulischen und elektrohydraulischen Steuerungseinrichtungen.
ANMERKUNG Einige Komponenten werden in anderen Teilen dieser Normenreihe behandelt.
Dieses Dokument gilt für Stempel, Stützzylinder und Zylinder, die bei Umgebungstemperaturen zwischen −10 °C und 60 °C eingesetzt werden.
Diese Norm identifiziert und berücksichtigt:
- Gefährdungen, die womöglich durch Stempel, Stützzylinder und Zylinder hervorgerufen werden;
- die Gefahrenbereiche und die Betriebsbedingungen, die irgendeine Art von Gefährdung verursachen können, und
- die Situationen, die zu Gefährdungen führen können, die eine Verletzung oder Gesundheitsschädigung verursachen;
- Gefahren, die durch Grubengas und/oder brennbare Stäube verursacht werden können.
Diese Norm beschreibt Verfahren zur Reduzierung dieser Gefährdungen.
Abschnitt 4 enthält eine Liste der behandelten Gefährdungen.
Dieses Dokument spezifiziert keine zusätzlichen Anforderungen für:
- besonders korrosive Umgebungen;
- Risiken bei Herstellung und Außerbetriebnahme;
- Erdbeben.
Ein kompletter hydraulischer Schreitausbau besteht aus den Ausbaugestellen (EN 1804 1:2020), Stempeln und Stützzylindern (EN 1804 2:2020) sowie den hydraulischen und elektrohydraulischen Steuerungseinrichtungen (EN 1804 3:2020). Die einzelnen Teile dieses mehrteiligen Dokuments befassen sich mit den Sicherheitsanforderungen der Komponenten, die in den Anwendungsbereichen der jeweiligen Teile dieser mehrteiligen Normenreihe genannt werden.
Dieses Dokument gilt nicht für Stempel und Zylinder, die vor dem Datum der Veröffentlichung dieses Dokuments hergestellt wurden.

Machines pour mines souterraines - Exigences de sécurité relatives aux soutènements marchants applicables aux piles - Partie 2 : Étançons et vérins à pose mécanisée

Le présent document stipule les exigences de sécurité relatives à l’utilisation des étançons et des vérins, telle que prévue par le fabricant. Ceux-ci comprennent les étançons, les vérins de soutènement et les vérins, y compris les rallonges mécaniques, les soupapes internes et les dispositifs de protection, les joints d’étanchéité, les raccords hydrauliques (y compris le 1er tuyau flexible ou la soupape de type B, voir l’EN 1804 3:2020) et leurs points de levage, mais à l’exclusion des tuyaux et gaines à cuir de protection, les soupapes externes, ainsi que les unités de commande hydrauliques et électro hydrauliques.
NOTE   Certains composants sont traités dans d’autres parties de la présente série de normes.
Le présent document s’applique aux étançons, vérins de soutènement et vérins qui sont utilisés à des températures ambiantes comprises entre −10 °C et 60 °C.
Le présent document identifie et tient compte :
-   des phénomènes dangereux potentiels pouvant résulter de l’utilisation des étançons, vérins de soutènement et vérins ;
-   des zones dangereuses et des conditions de fonctionnement susceptibles d’engendrer tout type de phénomène dangereux ;
-   des situations susceptibles d’engendrer des phénomènes dangereux pouvant entraîner des blessures ou porter atteinte à la santé ;
-   des dangers pouvant être causés par le gaz de mine (grisou) et/ou les poussières inflammables.
Le présent document décrit des méthodes permettant de réduire ces phénomènes dangereux.
L’Article 4 contient une liste des phénomènes dangereux traités.
Le présent document ne définit pas d’exigences supplémentaires concernant :
-   les milieux environnants particulièrement corrosifs ;
-   les risques associés à la fabrication et à la mise hors service ;
-   les tremblements de terre.
Un soutènement marchant complet est constitué des unités de soutènement (EN 1804-1:2020), des étançons et des vérins de soutènement (EN 1804-2:2020) et des systèmes de commande hydrauliques et électro-hydrauliques (EN 1804-3:2020). Chaque partie du présent document multipartie traite des exigences de sécurité des composants mentionnés dans le domaine d’application de la partie concernée.
Le présent document ne s’applique pas à tous les étançons et vérins fabriqués avant sa date de publication.

Stroji za podzemne rudnike - Varnostne zahteve za hidravlično podporje - 2. del: Hidravlične stojke in potisni hidravlični valji

General Information

• Status: Published
• Publication Date: 22-Dec-2020
• Withdrawal Date: 29-Jun-2021
• ICS: 73.100.10 - Tunnelling and tubbing equipment
• Technical Committee: CEN/TC 196 - Machines for undergroung mines - Safety
• Drafting Committee: CEN/TC 196/WG 3 - Hydraulic driven supports
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 23-Dec-2020
• Due Date: 26-Apr-2020
• Completion Date: 23-Dec-2020
• Directive: 2006/42/EC - Directive 2006/42/EC of the European Parliament and of the Council of 17 May 2006 on machinery, and amending Directive 95/16/EC (recast)
• Mandate: M/396 - Mandate to CEN and Cenelec for standardisation in the field of machinery
• Mandate: M/BC/CEN/91/1 - Standardization request to CEN/CENELEC concerning machines presenting hazards due to mobility or load lifting
• Ref Project: SIST EN 1804-2:2021 - Machines for underground mines - Safety requirements for hydraulic powered roof supports - Part 2: Power set legs and rams

Relations

• Replaces: EN 1804-2:2001+A1:2010 - Machines for underground mines - Safety requirements for hydraulic powered roof supports - Part 2: Power set legs and rams
• Effective Date: 13-Nov-2017

Overview

EN 1804-2:2020 - Machines for underground mines - Safety requirements for hydraulic powered roof supports - Part 2: Power set legs and rams (CEN) specifies safety requirements for legs, support rams and cylinders used in hydraulic powered roof supports in underground mining. The standard covers the mechanical extensions, internal valves and safety devices, seals, hydraulic connections up to the first hose line (or to the valve of design B per EN 1804-3:2020), and lifting points. It excludes protective pipes and gaiters, external valves and hydraulic/electrohydraulic control systems. Applicable ambient temperature range: -10 °C to 60 °C. EN 1804-2:2020 is a Type C standard prepared under EN ISO 12100 and supersedes EN 1804-2:2001+A1:2010.

Key topics and technical requirements

• Scope of components: legs, support rams, rams, mechanical extensions, internal valves/safety devices, seals and first hydraulic connection.
• Hazard identification: lists possible hazards, hazardous areas and operating conditions, scenarios causing injury or health impairment, and risks associated with mine gas and flammable dusts (Clause 4 and Annex C).
• Structural and material requirements: requirements for steel, light metals, seals, welding and calculated permissible stresses (axial, eccentric, weld stresses).
• Functional safety: internal valves, yield capability, behaviour under axial overload, eccentric loading, leak tightness and extension limits.
• Verification & testing: type testing and series verification, static/dynamic load testing, life tests and material testing (Annex A and B).
• User information: required documentation for installation, commissioning, operation, maintenance, handling, storage, marking and residual risk information.
• Exclusions & limits: not applicable to specially corrosive environments, manufacturing/decommissioning risks, earthquake scenarios, or legs/rams made before publication.

Applications and practical value

• Provides manufacturers, designers and safety engineers with harmonized safety requirements for hydraulic powered roof support actuators used in underground mines and tunnelling.
• Enables consistent type testing and verification procedures for hydraulic rams and legs, supporting product conformity and market surveillance.
• Helps mining operators and maintenance providers implement correct installation, operation and maintenance practices to reduce risks from hydraulic failures, leaks, overloads and exposure to mine gases/flammable dusts.

Who should use this standard

• Machine and component manufacturers (designers of hydraulic rams/legs)
• Mining equipment safety engineers and compliance officers
• Certification bodies, test laboratories and market surveillance authorities
• Maintenance teams and mine operators responsible for roof support systems

Related standards

• EN 1804-1:2020 - Support units (completes the hydraulic powered roof support system)
• EN 1804-3:2020 - Hydraulic and electrohydraulic control systems (interfaces with EN 1804-2)
• EN ISO 12100 - Machinery safety (type-C standard framework)

Keywords: EN 1804-2:2020, hydraulic powered roof supports, power set legs, rams, underground mines safety, hydraulic rams, support rams, CEN standard, mining machinery safety.

Standards Content (Sample)

SLOVENSKI STANDARD
01-april-2021
Nadomešča:
SIST EN 1804-2:2002+A1:2010
Stroji za podzemne rudnike - Varnostne zahteve za hidravlično podporje - 2. del:
Hidravlične stojke in potisni hidravlični valji
Machines for underground mines - Safety requirements for hydraulic powered roof
supports - Part 2: Power set legs and rams
Maschinen für den Bergbau unter Tage - Sicherheitsanforderungen für hydraulischen
Schreitausbau - Teil 2: Stempel und Zylinder
Machines pour mines souterraines - Exigences de sécurité relatives aux soutènements
marchants applicables aux piles - Partie 2 : Etançons et vérins à pose mécanisée
Ta slovenski standard je istoveten z: EN 1804-2:2020
ICS:
73.100.10 Oprema za gradnjo predorov Tunnelling and tubbing
in podzemnih železnic equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 1804-2
EUROPEAN STANDARD
NORME EUROPÉENNE
December 2020
EUROPÄISCHE NORM
ICS 73.100.10 Supersedes EN 1804-2:2001+A1:2010
English Version
Machines for underground mines - Safety requirements for
hydraulic powered roof supports - Part 2: Power set legs
and rams
Machines pour mines souterraines - Exigences de Maschinen für den Bergbau unter Tage -
sécurité relatives aux soutènements marchants Sicherheitsanforderungen für hydraulischen
applicables aux piles - Partie 2 : Étançons et vérins à Schreitausbau - Teil 2: Stempel und Zylinder
pose mécanisée
This European Standard was approved by CEN on 25 October 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 1804-2:2020 E
worldwide for CEN national Members.

Contents Page
European foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 7
4 Safety requirements . 9
4.1 General. 9
4.2 Lifting points . 9
4.3 Internal valves and safety devices . 9
4.4 Pressurized fluids . 10
4.5 Protection against ejecting fluids . 10
4.6 Yield capability . 10
4.7 Behaviour under axial overload . 10
4.8 Eccentric loading . 10
4.9 Functional reliability . 10
4.10 Leak tightness . 10
4.11 Extension limit . 11
4.12 Force introduction points of actuators . 11
4.13 Materials . 11
4.13.1 Steel. 11
4.13.2 Light metal . 11
4.13.3 Materials other than steel . 11
4.13.4 Seals . 12
4.14 Calculated permissible stresses . 12
4.14.1 Permissible stresses under axial central rated force conditions . 12
4.14.2 Permissible stresses under double axial central rated force conditions . 12
4.14.3 Permissible stresses under eccentric rated force conditions . 12
4.14.4 Permissible weld stresses . 12
4.15 Welding . 12
5 Verification of the safety requirements . 13
5.1 Type testing . 13
5.2 Series verification . 14
6 User information . 14
6.1 General requirements . 14
6.2 Technical and application data . 14
6.2.1 Introduction . 14
6.2.2 General description. 14
6.2.3 Performance data . 14
6.2.4 Hydraulic data . 14
6.2.5 List of additional drawings and documents . 14
6.3 Handling, transport and storage . 14
6.3.1 Introduction . 14
6.3.2 Handling and transport . 15
6.3.3 Storage . 15
6.4 Installation, commissioning, and operation . 15
6.4.1 Installation . 15
6.4.2 Commissioning . 15
6.4.3 Operation . 15
6.5 Maintenance . 16
6.5.1 Introduction . 16
6.5.2 Maintenance instructions . 16
6.5.3 Fault diagnosis and correction . 16
6.5.4 Preventative maintenance schedules . 16
6.5.5 Technical description . 16
6.6 Parts identification lists . 16
6.7 Marking / Identification . 17
6.8 Residual risk . 17
Annex A (normative) Tests for verification of the safety requirements . 18
A.1 Load tests . 18
A.1.1 General . 18
A.1.2 Testing with a central axial load . 18
A.1.3 Testing with eccentric force. 20
A.1.4 Life test . 20
A.1.5 Testing of lifting points . 22
A.2 Static calculation of actuators . 23
A.2.1 General . 23
A.2.2 Axial stresses . 23
A.2.3 Tangential stresses . 27
A.2.4 Radial stresses . 27
A.2.5 Combined stresses . 27
A.2.6 Individual components . 28
A.2.7 Symbols and units. 29
A.3 Testing the material properties . 29
A.3.1 General . 29
A.3.2 Weldability . 29
A.3.3 Mechanical properties . 30
A.3.4 Impact value . 30
Annex B (informative) List of tests . 31
Annex C (informative) List of significant hazards . 37
Annex ZA (informative) Relationship between this European Standard and the essential
requirements of Directive 2006/42/EC aimed to be covered . 40
Bibliography . 42

European foreword
This document (EN 1804-2:2020) has been prepared by Technical Committee CEN/TC 196 “Mining
machinery and equipment - Safety”, 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 June 2021, and conflicting national standards shall be
withdrawn at the latest by June 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 1804-2:2001+A1:2010.
The main differences between this document and EN 1804-2:2001+A1:2010 are as follows:
a) Normative references (updated);
b) Terms and definitions (modified);
c) List of significant hazards (revised) (see Annex C);
d) Requirements for steel (updated/modified);
e) Requirements for static and dynamic overload (revised/modified);
f) Requirements for overload fully retracted (deleted);
g) List of tests (updated) (see Annex B).
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(s).
For relationship with EU Directive(s), 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.
Introduction
This document is a type C standard, as specified in EN ISO 12100:2010.
The machinery concerned and the extent to which hazards, hazardous situations and events are covered
are indicated in the scope of this document.
This document is of relevance, in particular, for the following stakeholder groups representing the market
players with regard to machinery safety:
— machine manufacturers (small, medium and large enterprises);
— health and safety bodies (regulators, accident prevention organizations, market surveillance, etc.).
Others can be affected by the level of machinery safety achieved with the means of the document by the
above-mentioned stakeholder groups:
— machine users/employers (small, medium and large enterprises);
— machine users/employees (e.g. trade unions, organizations for people with special needs);
— service providers, e.g. for maintenance (small, medium and large enterprises);
— consumers (in the case of machinery intended for use by consumers).
The above-mentioned stakeholder groups have been given the possibility to participate at the drafting
process of this document.
The machinery concerned and the extent to which hazards, hazardous situations or hazardous events are
covered are indicated in the Scope of this document.
When requirements of this type-C standard are different from those which are stated in type-A or type-B
standards, the requirements of this type-C standard take precedence over the requirements of the other
standards for machines that have been designed and built according to the requirements of this type-C
standard.
The extent to which hazards are covered is indicated in the scope of this document. When drawing up
this standard, the underlying assumptions were that:
— only trained and qualified personnel operate the machine;
— components without specific requirements are:
— designed in accordance with the usual engineering practice and calculation codes;
— of sound mechanical construction;
— are free of defects;
— components are kept in good working order;
— the implementation conditions and requirements imposed on the machine have been agreed
between manufacturer of the legs and cylinders and their user (manufacturers of the support unit or
users in the case of spare parts).
1 Scope
This document stipulates the safety requirements for use of legs and rams as intended by the
manufacturer. These include legs, support rams and rams, including the mechanical extensions, the inner
valves and safety devices, seals, the hydraulic connections (up to the 1st hose line or to the valve of design
B, see EN 1804-3:2020) and their lifting points, but excluding protective pipes and gaiters, external valves
and hydraulic and electrohydraulic control systems.
NOTE Some components are discussed in other parts of this standard series.
This document applies for legs, support rams, and cylinders that are used at ambient temperatures
between –10 °C and 60 °C.
This document identifies and takes account of:
— possible hazards which may be caused by the operation of legs, support rams and rams;
— the hazardous areas and the operating conditions that can cause any type of hazard;
— the situations that can result in hazards that cause an injury or impair health;
— dangers that can be caused through mine gas and/or flammable dusts.
This document describes methods for reducing these hazards.
Clause 4 contains a list of the hazards discussed.
This document does not specify any additional requirements for:
— specially corrosive environments;
— risks associated with manufacturing and decommissioning;
— earthquake.
A complete hydraulic powered roof support consists of the support units (EN 1804-1:2020), legs and
support rams (EN 1804-2:2020) and the hydraulic and electro hydraulic controls (EN 1804-3:2020).
Each part of this multipart document addresses the safety requirements of the components mentioned
in the scopes of the respective parts of this multipart series.
This document is not applicable to legs and rams manufactured before the date of its publication.
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 1090-1:2009+A1:2011, Execution of steel structures and aluminium structures — Part 1: Requirements
for conformity assessment of structural components
EN 1804-1:2020, Machines for underground mines — Safety requirements for hydraulic powered roof
supports — Part 1: Support units and general requirements
EN 1804-3:2020, Machines for underground mines — Safety requirements for hydraulic powered roof
supports — Part 3: Hydraulic and electro hydraulic control systems
EN 10204:2004, Metallic products — Types of inspection documents
EN ISO 148-1:2016, Metallic materials — Charpy pendulum impact test — Part 1: Test method
(ISO 148-1:2016)
EN ISO 643:2020, Steels — Micrographic determination of the apparent grain size (ISO 643:2019,
Corrected version 2020-03)
EN ISO 6892-1:2019, Metallic materials — Tensile testing — Part 1: Method of test at room temperature
(ISO 6892-1:2019)
EN ISO 12100:2010, Safety of machinery — General principles for design — Risk assessment and risk
reduction (ISO 12100:2010)
EN ISO 15614-1:2017, Specification and qualification of welding procedures for metallic materials —
Welding procedure test — Part 1: Arc and gas welding of steels and arc welding of nickel and nickel alloys
(ISO 15614-1:2017, Corrected version 2017-10-01)
EN ISO 80079-36:2016, Explosive atmospheres — Part 36: Non-electrical equipment for explosive
atmospheres — Basic method and requirements (ISO 80079-36:2016)
ISO 7745:2010, Hydraulic fluid power — Fire-resistant (FR) fluids — Requirements and guidelines for use
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN ISO 12100:2010,
EN 1804-1:2020, EN 1804-3:2020 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at http://www.electropedia.org/
3.1
support unit
type of hydraulic powered roof support, e.g. frame support, chock support, shield support, consisting of
support components and support accessories
[SOURCE: EN 1804-1:2020, definition 3.1.1]
3.2
support components
all components which lie within the flow of the support bearing force
3.2.1
actuator
any type of hydraulic linear reciprocating device referred to in this document
3.2.2
legs and support rams
hydraulic actuators for producing the support bearing force of the support unit

As impacted by EN ISO 15614-1:2017/A1:2019.
3.2.3
single telescopic legs and support rams
hydraulic legs and support rams with one extension stage
3.2.4
multi telescopic legs and support rams
hydraulic legs and support rams with several extension stages
3.3
rams
all actuators which do not lie within the flow of the support bearing force but which are necessary for the
functioning of the powered roof support
3.4
control devices
3.4.1
valve
device for controlling the flow of hydraulic fluid
3.4.2
bursting blank
single acting hydraulic fuse
3.4.3
internal valve
valve inside actuator without access from outside
3.4.4
external valve
valve attached outside of the actuator
3.4.5
safety devices
type A valves according to EN 1804-3:2020
3.5
pressures
3.5.1
setting pressure
hydraulic pressure in the legs and support rams on completion of the setting procedure
Note 1 to entry: This pressure is supplied by the hydraulic system.
3.5.2
yield pressure of an actuator
hydraulic pressure in an actuator when the relevant pressure limiting valve is opened
Note 1 to entry: This pressure in the actuator is induced by external forces (yield forces; see EN 1804-1:2020,
3.5.1).
3.5.3
maximum permissible working pressure of an actuator
maximum hydraulic pressure at which a hydraulic component is intended be operated and/or yielded
3.6
rated actuator force
maximum force to which an actuator is designed
Note 1 to entry: It is a calculated value which is determined from the actuator geometry and the maximum
permissible working pressure, neglecting friction.
3.7
functions
3.7.1
extension
pushing out of the actuator operating piston by means of hydraulic pressure
3.7.2
retraction
drawing in of the actuator operating piston by means of hydraulic pressure
3.7.3
setting
extending of the support unit between the roof and the floor by pressuring the legs and support rams
3.7.4
yielding
alteration in length of an actuator which occurs when external forces cause the yield pressure to be
exceeded
4 Safety requirements
4.1 General
Machinery shall comply with the safety requirements and/or protective/risk reduction measures of this
clause. In addition, the machine shall be designed according to the principles of EN ISO 12100:2010 for
relevant but not significant hazards which are not dealt with by this document.
4.2 Lifting points
Where lifting points are fitted to actuators they shall be suitable for their intended purpose. They shall
be designed to have a calculated minimum factor of safety of 4 on ultimate breaking load in relation to
their intended load carrying capacity. They shall be clearly and permanently marked with their load
carrying capacity, e.g. by welding.
4.3 Internal valves and safety devices
Actuators that can be externally overloaded shall be protected against excessive pressure.
This can be by means of:
— internal valves;
— external valves (see EN 1804-3:2020);
— safety devices such as bursting blanks.
The pressure in the piston compartment of hydraulic legs shall be capable of being monitored so that
leakages are recognized in good time and hazards from inadequate strata control as a result of a pressure
drop in the legs are avoided.
As a result of the type of fluid used and the small number of pressure cycles per day, actuators of hydraulic
powered roof supports need neither to be self-bleeding nor shall they have external air bleeds.
In addition, internal valves, excluding constant yield valves, are covered by EN 1804-3:2020.
4.4 Pressurized fluids
Actuators shall be either designed such that they use:
a) fire-resistant fluids category HFA (ISO 7745:2010) specified by the support unit manufacturer in
accordance with ISO 7745:2010, 6.2.1;
or
b) water without additives (temperatures from +5 °C to +60 °C).
Hydraulic systems of roof supports, designed for coal mines and other mines with potentially explosive
atmospheres, should be designed for use with non-toxic and fire-resistant fluids in accordance with
SHCMOEI 7th Report (see Bibliography).
4.5 Protection against ejecting fluids
Actuators that intentionally eject fluid in to the atmosphere shall be designed to prevent any hazard due
to the releasing fluid (e.g. by means of a guard).
4.6 Yield capability
Legs and support rams shall be designed such that at yield pressure they are capable of supporting the
forces and the movements of attached components, see Annex A and see EN 1804-1:2020, 4.3.1.
4.7 Behaviour under axial overload
Legs and support rams, including their mechanical extensions, shall be designed so that their function is
not affected if
— they are subjected statically to 1,5 times the rated compressive or tensile force and dynamically to a
mechanical impact load resulting in 1,5 times the maximum permissible working pressure (see
Annex A);
or
— they are subjected statically to 2 times the rated compressive or tensile force. After the load test, the
function may be impaired, but it shall not burst nor shall parts or fluid be ejected.
Rams, including their mechanical extension pieces, shall be designed so that their function is not affected
if subjected statically to 1,5 times the rated compressive or tensile force (see Annex A).
4.8 Eccentric loading
Legs and support rams including their extension pieces shall be capable of withstanding eccentric and/or
lateral forces without their function being impaired (see Annex A).
4.9 Functional reliability
The functional reliability of legs and supporting rams including their extension pieces shall not be
impaired after 21 000 load cycles (see A.1.4.1 and A.1.4.2).
4.10 Leak tightness
Pressure compartments of actuators shall be leak tight when isolated (see Annex A).
4.11 Extension limit
Extension limits of legs and support rams shall withstand a pressure of at least 80 % of the maximum
permissible working pressure without damage when the fully extended piston is loaded 100 times with
this pressure. If the design of the hydraulic circuitry of the support unit is such that it is possible
operationally to generate pressures higher than 80 % of the maximum permissible working pressure,
legs and support rams shall remain undamaged at these higher pressures and under the above-
mentioned conditions.
Rams shall withstand 1,5 times the maximum permissible working pressure when the piston is in fully
extended in contact with the internal stop.
Support rams that are subjected to tensile load in operation shall not be damaged when they are fully
extended in contact with the internal stop and loaded with 1,5 times the rated tensile force.
4.12 Force introduction points of actuators
The force introduction points of actuators and their extension pieces shall be capable of withstanding
1,5 times the rated actuator force without their function being affected.
4.13 Materials
4.13.1 Steel
4.13.1.1 General
The materials of the support parts shall be specified by the manufacturer with consideration of the
following requirements. Verification of the properties shall be provided with Acceptance Certificate 3.1
in accordance with EN 10204:2004 or better.
The ultimate tensile strength of the types of steel used shall be at least 1,08 × the determined yield
strength or 0,2 % elasticity limit, if the calculated stresses are more than 90 % of the permissible stresses
(see 4.13.1).
The elongation prior to fracture A of the steel grades used shall not be less than 10 %.
4.13.1.2 Steel for welded actuator components
The steel shall be of fine grain, (ferrite grain size 6 or finer as described in EN ISO 643:2020) and shall
have an impact value of at least 27 J at a temperature of −20 °C.
4.13.1.3 Steel for non-welded actuator components
The steel used for the non-welded tubes of actuators shall have properties as described in 4.13.1.1 and
4.13.1.2.
The steel used for the other components shall have an impact value of at least 25 J at a temperature of
20 °C.
4.13.2 Light metal
Surfaces of actuators consisting of light metal or light metal alloys (including paints and coatings
containing light metal) intended by the manufacturer to be used in potentially gaseous mines shall meet
the requirements of EN ISO 80079-36:2016, 6.4.4.
4.13.3 Materials other than steel
For materials that are used for the manufacture of actuator components, equivalent ductility
characteristics to those specified for steel in 4.13.1 shall be proven. Non-metallic materials shall meet the
requirements of EN ISO 80079-36:2016, 7.4.
4.13.4 Seals
Actuator seals shall fulfil the test requirements given in Annex A.
4.14 Calculated permissible stresses
4.14.1 Permissible stresses under axial central rated force conditions
The axial stresses in the individual parts of the actuators shall not exceed 70 % of the guaranteed yield
point, 0,2 % proof stress or compressive limit of the materials (also valid for annular stresses as a result
of fluid pressure).
The axial stresses in the bases of actuators shall not exceed 80 % of the guaranteed yield point, 0,2 %
proof stress or compressive limit of the materials.
The shear stresses shall not exceed 65 % of the guaranteed yield point, 0,2 % proof stress or compressive
limit of the materials.
4.14.2 Permissible stresses under double axial central rated force conditions
In the case of twice the central rated force in the fully retracted state of legs and support rams, the stresses
shall not exceed the guaranteed yield point or 0,2 % proof stress of the materials.
NOTE This requirement only involves mechanical loading. There are no hydraulic pressures.
4.14.3 Permissible stresses under eccentric rated force conditions
In the case of the eccentric rated force as described in A.1.3.1 the axial stresses of the leg and support ram
components involved in bending shall not exceed the guaranteed yield point or 0,2 % proof stress or
compressive limit of the materials. The deflections determined by means of a test as specified in A.1.3.2
shall be used as a basis for calculating the stresses.
In the case of an eccentric rated force and simultaneous lateral loading (e.g. to stabilize the support unit),
the axial stresses of the leg and support ram components involved in bending shall not exceed the
guaranteed yield point or 0,2 % proof stress or compressive limit of the materials.
4.14.4 Permissible weld stresses
The weld stresses shall not exceed the permissible stresses of the adjacent materials given in Table 1, if
the welds are not subjected to any non-destructive testing.
Table 1 — Permissible weld stresses (4.13.1 to 4.13.3)
Weld types Axial stresses Shear stresses Combined stresses
Fillet welds 65 % 65 % 100 %
Butt welds 80 % 80 % 100 %
Where these stresses are exceeded due to result of non-destructive testing the manufacturer shall
document them specially.
4.15 Welding
Welding of roof support power set legs and rams shall be in accordance with the requirements min. EXC2
of EN 1090-1:2009+A1:2011.
5 Verification of the safety requirements
5.1 Type testing
One specimen of the actuator shall be type tested in accordance with Annex A. The test requirements
given in Annex A shall be met. The following documents shall be made available for the type test:
— user information;
— results of the static calculation in accordance with A.2;
— manufacturing drawings;
— drawings of welded parts;
— evidence of the competence of the welding workshop;
— data relating to the material characteristics;
— data relating to the seals used.
The specimen which has been tested according to Annex A should not be placed on the market.
If no provision has been made in Annex A for verification of the requirements in Clause 5 by specified
tests, they shall be verified by means of visual inspection, function test or reference to documents.
Verification of the safety requirements is shown in Table 2.
Table 2 — Tests verification of the safety requirements
Safety requirements Confirmation
4.2 * See A.1.5
4.3 * Visual inspection/comparison with the manufacturer's drawings
4.4 * Inspection of the oil-manufacturer's test documentation
4.5 * Visual inspection/comparison with the manufacturer's drawings
4.6 * See A.1.2.2
4.7 * See A.1.2.3
4.8 * See A.1.3
4.9 * See A.1.4
4.10 * See A.1.2.4
4.11 * See A.1.2.1 and A.1.4.3
4.12 * See A.1.2.3.1
4.13 ** See A.3
4.14 * See A.2
4.15 ** See A.3.2
6.4 * Inspection of manufacturer's test documentation
* Type test.
** Series test.
5.2 Series verification
See Table 2; Verification with **.
6 User information
6.1 General requirements
The actuator manufacturer shall provide user information meeting the requirements of
EN ISO 12100:2010 and Clause 6.
The user information shall be the primary source of information on a complete actuator and shall contain
all the information relating to its safe application and this shall be produced as an instruction handbook
as specified in EN ISO 12100:2010.
Clause 6 user information of EN 1804-1:2020 also applies to this document and is complemented, as
appropriate, by corresponding clauses in those parts.
Care shall be taken to ensure that the user information is available to the user on receipt of the actuator.
6.2 Technical and application data
6.2.1 Introduction
The user information shall describe the intended use of the actuator.
The operating instruction shall include all design and performance data necessary, to make an
assessment of suitability for use in particular applications and environments, and for the identification of
any energy supply requirements and other ancillary facilities that may be needed. The information
provided shall comply with 6.2.2 to 6.2.5.
6.2.2 General description
This description shall explain clearly, and in logical sequence the overall function of the actuator with all
special features and characteristics. General arrangement drawings shall be provided as appropriate.
6.2.3 Performance data
The principal dimensions, weights and performance data of the complete actuator shall be given.
6.2.4 Hydraulic data
The data necessary to design the hydraulic system including yield and setting characteristics shall be
given. In addition, it shall include a list of the hydraulic fluids specified by the manufacturer of the actuator
(see 4.3).
6.2.5 List of additional drawings and documents
A complete listing of all drawings, illustrations, and other documents, e.g. including information
concerning the welding shop, that are components of the user information, shall be made available
separately. The list shall include appropriate cross-references to the text of the user information.
6.3 Handling, transport and storage
6.3.1 Introduction
This section of the user information shall include information and instructions for the safe handling,
transport and storage of the actuator.
6.3.2 Handling and transport
The details shall include:
a) weights and outline dimensions of all the supplied actuators;
b) precautions to be taken during handling and transportation. In addition, indications of possible
damage to the actuators during handling and transport;
c) information on the number and rated load of any ancillary lifting equipment (e.g. shackles, eye bolts)
not supplied but necessary in order to enable safe lifting/installation of the actuators.
6.3.3 Storage
The following information shall be given for the storage of the actuator on the surface and underground:
a) methods of preservation;
b) instructions for preparing the actuator for use after storage.
6.4 Installation, commissioning, and operation
6.4.1 Installation
The installation of the actuator into the support unit shall be described together with details of any special
tools that may be required.
Reference shall be made to the user information supplied for the support unit (e.g. compatibility).
6.4.2 Commissioning
Details shall include:
a) checking the correct installation prior to connection to the pressure supply and information on the
necessary cleaning and flushing procedures;
b) connection of hydraulic pressure supply;
c) commissioning the actuator and testing individual functions.
6.4.3 Operation
This section of the user information shall include the information and instructions necessary for the safe
operation of the actuators.
Details shall be given for the correct use, with information on the operating range and prohibited
applications.
6.5 Maintenance
6.5.1 Introduction
This section of the user information shall contain the necessary information and instructions to enable
the actuator to be maintained in, or restored to, safe working order. The information provided shall be
according to 6.5.2 to 6.5.5.
6.5.2 Maintenance instructions
Instructions shall be provided, with illustrations where necessary, detailing the methods and procedures
for preventative and corrective maintenance. The instructions shall include reference to the following:
a) dismantling and re-assembly;
b) replacement and adjustment;
c) a parts identification list;
d) special tools and additional equipment;
e) hazards which may arise and precautions to be taken.
6.5.3 Fault diagnosis and correction
Information and instructions shall be included on fault diagnosis and correction.
6.5.4 Preventative maintenance schedules
Schedules shall be provided and include information on the nature and frequency of inspections, tests,
maintenance and discard criteria required to keep the actuator in safe working order.
6.5.5 Technical description
This shall be in the form of a comprehensive functional description of the actuator and its main
components with appropriate illustrations designed to enable the text to be kept concise and easily
understandable. The description shall include details of the safety devices and measures for preventing
hazards that may arise from malfunction of the equipment.
6.6 Parts identification lists
A parts identification list shall be provided which shall include the part numbers and sufficiently full
descriptions for positive identification of all assemblies, sub-assemblies and components of the actuator.
The list shall also identify:
a) those parts which the manufacturer envisages being changed in the working environment;
b) those parts which the manufacturer recommends should be held as spares.
Parts identification lists shall be illustrated by drawings, photographs, etc. as appropriate, so that each
component listed may be readily identified and located.
6.7 Marking / Identification
Each actuator shall be permanently marked with at least the following:
a) the business name and full address of the manufacturer;
NOTE If space is restricted, the registered company logo or trademark can be used.
b) year of manufacture;
c) serial number, if any;
d) maximum permissible working pressures;
e) rated forces (ten
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