SIST EN 14359:2007
(Main)Gas-loaded accumulators for fluid power applications
Gas-loaded accumulators for fluid power applications
1.1 This European Standard specifies the requirements for materials, design, manufacture, testing inspection, safety systems and documentation (including instructions for first operation), for commonly-used types of gas-loaded accumulators and gas bottles for fluid power applications (see 1.2).
1.2 This European Standard applies to the following types of components, defined as the pressure-containing envelope of gas-loaded accumulators:
bladder type;
diaphragm type;
piston type;
transfer type;
gas bottles used to provide additional gas capacity.
They consist of one or several parts joined together by a variety of mechanical means and by welding.
1.3 This European Standard applies to gas-loaded accumulators which operate with the following conditions:
subject to an internal gauge pressure greater than 0,5 bar;
working temperature of not lower than –50 °C and not higher than +200 °C;
containing Group 2 liquids and gases as defined in the Pressure Equipment Directive 97/23/EC.
It does not apply to:
accumulators for use with dangerous fluids (see NOTE 1).
NOTE 1 Fluid power applications utilize non-dangerous fluids as categorized in ISO 6743-4 in addition to an inert gas (e.g. nitrogen) which is used as the pre-charging medium.
NOTE 2 There are no design limits to the volume of the accumulator.
Hydrospeicher für Hydraulikanwendungen
1.1 Diese Europäische Norm beschreibt die Anforderungen an Werkstoffe, Konstruktion, Herstellung, Prüfung, Sicherheitssysteme und Dokumentation (einschließlich Anleitungen für die erste Inbetriebnahme) für die allgemein gebräuchlichen Bauarten von Gasdruckspeichern und Gasbehältern für hydraulische Anwendungen (siehe 1.2).
1.2 Diese Europäische Norm gilt für folgende Bauteile, die als druckbeaufschlagte Gehäuse von Gasdruck¬speichern definiert sind:
- Blasenspeicher;
- Membranspeicher;
- Kolbenspeicher;
- Transferspeicher;
- Gasbehälter zur Vergrößerung des Gasvolumens.
Diese können aus einem oder mehreren Gehäuseteilen bestehen, die auf unterschiedliche Art und Weise miteinander verbunden sind, einschließlich Schweißverfahren.
1.3 Diese Europäische Norm gilt für Gasdruckspeicher, die unter folgenden Bedingungen arbeiten:
- der Innendruck ist größer als 0,5 bar;
- die Betriebstemperatur ist nicht niedriger als – 50 °C und nicht höher als + 200 °C;
- sie werden mit Flüssigkeiten und Gasen der Gruppe 2 betrieben, wie sie in der Druckgeräte-Richtlinie 97/23/EG definiert sind.
Sie gilt nicht für:
- Hydrospeicher, die mit gefährlichen Fluiden betrieben werden (siehe ANMERKUNG 1).
ANMERKUNG 1 Hydrospeicher werden in Hydraulikanwendungen mit ungefährlichen Flüssigkeiten betrieben, wie sie in
ISO 6743-4 definiert sind; gleichzeitig wird ein inertes Gas (z. B. Stickstoff) als Füllgas verwendet.
ANMERKUNG 2 Es gibt keine Begrenzung für das Volumen der Hydrospeicher nach dieser Norm.
Accumulateurs hydropneumatiques pour transmissions hydrauliques
1.1 La présente Norme européenne spécifie les exigences relatives aux matériaux, a la conception, a la
fabrication, aux contrôles, aux systemes de sécurité et a la documentation (y compris les instructions pour la
premiere mise en service) applicables aux accumulateurs hydropneumatiques de types courants et bouteilles
a gaz pour transmissions hydrauliques (voir 1.2).
1.2 La présente Norme européenne s’applique aux types de composants suivants, définis comme étant
l’enveloppe sous pression des accumulateurs hydropneumatiques :
-type a vessie ;
- type a membrane ;
- type a piston ;
- type transfert ;
-bouteilles a gaz utilisées en tant que capacité additionnelles.
Ils sont constitués d’une ou de plusieurs parties assemblées par différents moyens mécaniques y compris le
soudage.
1.3 La présente Norme européenne s’applique aux accumulateurs hydropneumatiques fonctionnant dans
les conditions suivantes :
- soumis a une pression manométrique interne supérieure a 0,5 bar ;
- la température de fonctionnement est comprise entre -50 °C et +200 °C ;
- contenant des liquides et des gaz du groupe 2 tel que défini dans la Directive Equipements sous
pression 97/23/CE.
Elle ne s’applique pas aux :
- accumulateurs destinés a etre utilisés avec des fluides dangereux (voir NOTE 1).
NOTE 1 Les applications de transmissions hydrauliques utilisent des fluides non dangereux classés selon les
catégories de l’ISO 6743-4 conjointement avec un gaz inerte (par exemple de l’azote) qui est utilisé comme produit de
précharge.
NOTE 2 Les accumulateurs ne sont soumis a aucune restriction de conception relative a leur volume.
Hidropnevmatski zalogovniki za hidravlične razvode
General Information
Relations
Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Gas-loaded accumulators for fluid power applicationsAccumulateurs hydropneumatiques pour transmissions hydrauliquesHydrospeicher für HydraulikanwendungenTa slovenski standard je istoveten z:EN 14359:2006SIST EN 14359:2007en23.100.99Other fluid power system componentsICS:SLOVENSKI
STANDARDSIST EN 14359:200701-marec-2007
EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 14359October 2006ICS 17.040.30 English VersionGas-loaded accumulators for fluid power applicationsAccumulateurs hydropneumatiques pour transmissionshydrauliquesHydrospeicher für HydraulikanwendungenThis European Standard was approved by CEN on 18 September 2006.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the Central Secretariat or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania,Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2006 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 14359:2006: E
EN 14359:2006 (E) 2 Contents Page Foreword.5 1 Scope.6 2 Normative references.7 3 Terms, definitions, symbols, units and abbreviated terms.8 3.1 Terms and definitions.8 3.2 Symbols, units and abbreviated terms.9 3.2.1 General.9 3.2.2 Inter-relation of thickness definitions.10 4 Materials.10 4.1 Requirements for metallic materials.10 4.2 Material certificates for components of the pressure containing envelope.11 5 Basic design and calculation criteria.11 5.1 General.11 5.2 Corrosion.11 5.3 Qualification by similarity.11 5.4 Design methods.11 5.4.1 General.11 5.4.2 Basic symbols, units and description.12 5.4.3 Maximum allowable values for the nominal design stress for pressure bearing parts.13 5.5 Design and calculation methods common to all accumulator types.13 5.5.1 General.13 5.5.2 Specific definitions.13 5.5.3 Cylindrical shells.14 5.5.4 Dished ends under internal pressure.14 5.5.5 Isolated openings and nozzles in spherical shells and spherical centre areas of dished ends.17 5.5.6 Thread calculation.23 5.6 Specific design criteria for piston accumulators.25 5.6.1 Threaded end caps.25 5.6.2 Tie-rod retained end caps.30 5.6.3 Split-ring retained end caps.32 5.7 Specific design criteria for diaphragm accumulators.35 5.7.1 General.35 5.7.2 Two-part screwed shell design.36 5.7.3 Three-part screwed shell design.38 5.7.4 Gas-precharging openings.42 5.8 Specific design criteria for oil ports mainly used in bladder type accumulators.43 5.8.1 General.43 5.8.2 Oil port design and calculation.43 6 Manufacture.46 6.1 General.46 6.2 Special manufacturing processes for welded diaphragm accumulators.46 6.2.1 General.46 6.2.2 Requirements for the use of permanent backing strips.46 6.2.3 Electron and laser beam welding.47 6.2.4 Welded nozzles.47 6.2.5 Heat treatment.47 6.2.6 Approval of special welding procedures.48
EN 14359:2006 (E) 3 6.2.7 Qualification of welding procedure specifications.48 6.2.8 Verification and utilization of welding procedure specifications when applied to welding machines.48 6.3 Forming of bladder accumulator shells.48 6.3.1 Processes.48 6.3.2 Heat treatment.49 6.3.3 Verification of mechanical properties.49 6.3.4 Visual and ultrasonic examination.50 7 Inspection and testing.51 7.1 General.51 7.2 Design documentation.51 7.3 Design review and design examination.52 7.4 Inspection during manufacture.52 7.5 Hydrostatic pressure test.52 7.6 Fatigue test.53 7.6.1 General.53 7.6.2 Basic symbols and units.53 7.6.3 Test equipment and preparation of test accumulator.54 7.6.4 Accuracy.55 7.6.5 Test conditions and procedure.55 7.6.6 Method of evaluating and interpreting fatigue test results using the gradient of the stress-number curve and a probability of failure.57 7.6.7 Fatigue assessment of gas loaded accumulators – Guarantee factor method).63 7.7 Marking and labelling.70 7.7.1 General.70 7.7.2 Marking method.71 7.7.3 Marking contents.71 7.7.4 Information labelling.71 7.8 Documentation.71 7.8.1 General.71 7.8.2 Process records.72 8 Safety instructions and equipment for accumulators.72 8.1 Introduction.72 8.2 Safety equipment.72 8.2.1 General.72 8.2.2 Limitation of pressure.73 8.2.3 Pressures gauges.74 8.2.4 Shut-off devices.74 8.2.5 Fluid side pressure release devices.74 8.2.6 Gas side release devices.74 8.3 Tests and examinations before first operation.75 8.3.1 Examination of documentation including instructions for first operation, stamps and CE-marks.75 8.3.2 Examination of proper mounting.75 8.3.3 Examination of safety equipment.75 8.4 Supervision and maintenance.76 Annex A (informative)
Categories of gas-loaded accumulators including reference to modules of conformity assessment.77 Annex B (informative) Summary of activities in respect to conformity assessment modules.78 Annex C (informative)
Examples of safety equipment configuration.79 Annex D (informative)
Manufacturer's declaration of conformity form.86 Annex E (informative)
Example of the application of the method of evaluating and interpreting fatigue test results carried out on complete accumulators.87 E.1 General.87 E.1.1 General.87 E.1.2 Consider a population of accumulators with the following characteristics:.87
EN 14359:2006 (E) 4 E.1.3 Calculation of CVM.87 E.1.4 Calculation of M.88 E.1.5 Calculation of CVE.88 Annex F (informative)
Abacus.90 Annex G (informative)
Alternative relations for normal distributions.93 Annex H (informative)
Variation coefficients of equipment material.94 Annex I (informative)
Quality / severity condition of equipment / environment.95 I.1 Equipment quality: ki values.95 I.2 Severity conditions of environment: Ej values.95 Annex ZA (informative)
Relationship between this European Standard and the Essential Requirements of EU Directive 97/23/EC.96 Bibliography.97
EN 14359:2006 (E) 5 Foreword This document (EN 14359:2006) has been prepared by Technical Committee CEN/TC 54 “Unfired pressure vessels”, the secretariat of which is held by BSI. 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 April 2007, and conflicting national standards shall be withdrawn at the latest by April 2007. Where appropriate, equations and techniques are consistent with the requirements of
EN 13445-3:2002 but this European Standard is presumed to satisfy the essential requirements of the Pressure Equipment Directive 97/23/EC in its own right. NOTE If any matter of interpretation or doubt arises as to the meaning or effect of any normative part of this European Standard, or as to whether anything should be done or has been omitted to be done, in order that this European Standard should be complied with in full, the matter needs to be referred to the CEN/TC 54 Committee. 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 organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EN 14359:2006 (E) 6 1 Scope 1.1 This European Standard specifies the requirements for materials, design, manufacture, testing inspection, safety systems and documentation (including instructions for first operation), for commonly-used types of gas-loaded accumulators and gas bottles for fluid power applications (see 1.2). 1.2 This European Standard applies to the following types of components, defined as the pressure-containing envelope of gas-loaded accumulators: bladder type; diaphragm type; piston type; transfer type; gas bottles used to provide additional gas capacity. They consist of one or several parts joined together by a variety of mechanical means and by welding. 1.3 This European Standard applies to gas-loaded accumulators which operate with the following conditions: subject to an internal gauge pressure greater than 0,5 bar; working temperature of not lower than –50 °C and not higher than +200 °C; containing Group 2 liquids and gases as defined in the Pressure Equipment Directive 97/23/EC. It does not apply to: accumulators for use with dangerous fluids (see NOTE 1). NOTE 1 Fluid power applications utilize non-dangerous fluids as categorized in ISO 6743-4 in addition to an inert gas (e.g. nitrogen) which is used as the pre-charging medium. NOTE 2 There are no design limits to the volume of the accumulator.
EN 14359:2006 (E) 7 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 1043-1, Destructive tests on welds in metallic materials — Hardness testing — Part 1: Hardness test on arc welded joints EN 1968:2002, Transportable gas cylinders — Periodic inspection and testing of seamless steel gas cylinders EN 10002-1, Metallic materials — Tensile testing — Part 1: Method of test at ambient temperature EN 10045-1, Metallic materials — Charpy impact test — Part 1: Test method EN 10204:2004, Metallic products — Types of inspection documents EN 13018, Non-destructive testing — Visual testing — General principles EN 13445-2:2002, Unfired pressure vessels — Part 2: Materials EN 13445-3:2002, Unfired pressure vessels — Part 3: Design EN 13445-4, Unfired pressure vessels — Part 4: Fabrication EN ISO 898-1:1999, Mechanical properties of fasteners made of carbon steel and alloy steel — Part 1: Bolts, screws and studs (ISO 898-1:1999) EN ISO 6506-1, Metallic materials — Brinell hardness test — Part 1: Test method
(ISO 6506-1:2005) EN ISO 6506-2, Metallic materials — Brinell hardness test — Part 2: Verification and calibration of testing machines (ISO 6506-2:2005) EN ISO 6506-3, Metallic materials — Brinell hardness test — Part 3: Calibration of reference blocks (ISO 6506-3:2005) EN ISO 15614-1, 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 15614-1:2004) ISO 262, ISO general-purpose metric screw threads — Selected sizes for screws, bolts and nuts ISO 9110-1, Hydraulic fluid power — Measurement techniques — Part 1: General measurement principles ISO 9110-2, Hydraulic fluid power — Measurement techniques — Part 2: Measurement of average steady-state pressure in a closed conduit ISO 10771-1, Hydraulic fluid power — Fatigue pressure testing of metal pressure-containing envelopes — Part 1: Test method
EN 14359:2006 (E) 8 3 Terms, definitions, symbols, units and abbreviated terms 3.1 Terms and definitions For the purpose of this document, the following terms and definitions apply. 3.1.1 gas-loaded accumulator hydraulic accumulator with separator between liquid and gas where the liquid is pressurized using the compressibility of an inert gas (for example nitrogen). The separator can be a bladder, a diaphragm or a piston. Gas-loaded accumulators have shells, which can consist of cylinders, dished ends and flat plates. Openings are always isolated, located on the axis centre line and positioned at both ends of the accumulator. It is assumed that such vessels are axis-symmetrical 3.1.2 bladder accumulator gas-loaded accumulator consisting of pressure-retaining shell, either spun-forged from seamless tube, hammer-forged from hollow bar or of welded construction, in which the liquid and gas are separated by a flexible bag or bladder normally retained at one end of the shell 3.1.3 diaphragm accumulator gas-loaded accumulator consisting of pressure-retaining shell assembly, in which the construction can either be screwed or welded, with integral ports in which the liquid and gas are separated by a flexible membrane normally retained at its largest diameter to the shell 3.1.4 piston accumulator gas-loaded accumulator consisting of cylinder body and end cap assemblies in which the liquid and gas are separated by a rigid sliding piston 3.1.5 transfer type accumulator gas-loaded accumulator with a port for connecting additional gas capacity from one or more gas bottle(s) 3.1.6 gas bottle inter-connected pressure vessels consisting of body and, depending upon construction, port assemblies used to provide additional gas capacity and communicating with the gas chamber of the accumulator by means of a pipe connection
EN 14359:2006 (E) 9 3.2 Symbols, units and abbreviated terms 3.2.1 General For the purposes of this document, the following symbols, units and abbreviated terms apply.
Table 3.2-1 — Symbols, characteristics and units Symbol Characteristics Unit e Required thickness of the component, when obtained by direct calculation or the assumed thickness of the component, when obtained by non-direct calculation mm a ea Analysis thickness of the component = en-δe-δm-c mm a en Nominal thickness of the component, as specified on the manufacturing detail drawings mm a c Corrosion allowance mm a δe Absolute value of the negative tolerance taken from the material standard of the component mm a δm Possible thinning during manufacturing process of the component mm a N Number of pressure cycles
P0 Pre-charging pressure; the gas pressure in the accumulator when the hydraulic circuit is not under pressure (initial state) at a temperature of
(20 ± 5) °C MPa b P1 Minimum working pressure of the hydraulic circuit MPa b P2 Maximum working pressure of the hydraulic circuit MPa b P3 Set pressure of the safety accessory for the accumulator, if one is fitted MPa b PS Maximum allowable pressure, the pressure for which the accumulator has been designed and/or qualified by test MPa b PT Test pressure MPa b P2/P0 Allowable pressure ratio below which the accumulator type can be used
ReH Minimum upper yield strength MPa b Rm Minimum tensile strength MPa b Rm/t Minimum tensile strength at design temperature t °C MPa b Rp0,2 Minimum 0,2 % - proof strength MPa b Rp0,2/t Minimum 0,2 % - proof strength at design temperature t °C MPa b Rp1,0 Minimum 1,0 % - proof strength MPa b Rp1,0/t Minimum 1,0 % - proof strength at design temperature t °C MPa b TSmin
Minimum operating temperature of the hydraulic fluid or of the environment, whichever is lower or equal °C TSmax
Maximum operating temperature of the hydraulic fluid or of the environment, whichever is higher or equal °C V Internal volume of the gas chamber litre V0 Gas volume at pressure P0 litre V1, V2 Volumes occupied by the gas contained in the accumulator and the additional chambers, if any, at pressures P1 and P2 at their respective temperatures litre z Weld joint coefficient
a
The relationships between the defined thicknesses are shown in Figure 3.1. b
MPa for calculation purposes only, otherwise the unit should be bar (1 MPa = 10 bar).
EN 14359:2006 (E) 10 3.2.2 Inter-relation of thickness definitions The inter-relation of the various definitions of thickness is shown in Figure 3.1.
enemceeaδδ
Key e required thickness en nominal thickness ea analysis thickness (en-δe-δm-c) c corrosion allowance δe
absolute value of the negative tolerance taken from the material standard of the component δm
possible thinning during manufacturing process of the component Figure 3.1 — Relationship of thickness definitions 4 Materials 4.1 Requirements for metallic materials The pressure containing envelope of gas-loaded accumulators shall be constructed of either: harmonised materials used for the manufacture of unfired pressure vessels and meeting the requirements of EN 13445-2:2002; materials other than those specified in EN 13445-2:2002 provided that they have been accepted by a particular material appraisal; materials covered by a European approval for materials in accordance with Article 11 of Pressure Equipment Directive 97/23/EC. 4.2 Material certificates for components of the pressure containing envelope Components used in the manufacture of the pressure containing envelope of gas-loaded accumulators to category II, III and IV according to Annex II of the Pressure Equipment Directive 97/23/EC, shall be accompanied by an inspection document in accordance with EN 10204:2004 type 3.1 – see Annex B.
EN 14359:2006 (E) 11 5 Basic design and calculation criteria 5.1 General The requirements of Clause 5 shall apply when the materials and welds are not subject to localised corrosion in the presence of either products which the gas-loaded accumulator is to contain, or the environment in which it is located. 5.2 Corrosion A corrosion allowance is not normally required for accumulators covered by this European Standard. Where there is a risk of corrosion, a protection method and/or corrosion allowance shall be applied to the affected surfaces of the accumulator. 5.3 Qualification by similarity Accumulators are often serially produced and it is possible to qualify a range of accumulators based upon the design, calculation and testing of one model within the range provided that other accumulators are similar. Two accumulators are similar provided that: they are made of the same material of the same form and origin; they are identical with the exception of length; the internal length of the cylindrical portion is not less than three times its external diameter. If the length of the cylindrical portion is less than three times its external diameter, then a detailed stress analysis shall be undertaken. 5.4 Design methods 5.4.1 General This European Standard specifies methods for the design by equations of accumulators or accumulator components. Satisfactory application of such equations alone shall be sufficient to demonstrate conformity to this European Standard provided the accumulator will be subjected to less than 500 pressure cycles between P2 and P1 during its lifetime. Where the accumulator will be subjected to more than 500 pressure cycles between P2 and P1, the manufacturer shall make an assessment for the effects of fatigue, either by analysis or test. This assessment shall form part of the Technical Documentation File. Clauses 17 and 18 of EN 13445-3:2002 shall be used as the basis for a fatigue analysis and 7.6 of this European Standard shall be used as the method fo
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