EN 14359:2006+A1:2010

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Hydrospeicher für HydraulikanwendungenAccumulateurs hydropneumatiques pour transmissions hydrauliquesGas-loaded accumulators for fluid power applications23.100.99Other fluid power system componentsICS:Ta slovenski standard je istoveten z:EN 14359:2006+A1:2010SIST EN 14359:2007+A1:2011en,fr,de01-februar-2011SIST EN 14359:2007+A1:2011SLOVENSKI
STANDARDSIST EN 14359:20071DGRPHãþD

EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 14359:2006+A1
December 2010 ICS 23.100.99 Supersedes EN 14359:2006English Version
Gas-loaded accumulators for fluid power applications
Accumulateurs hydropneumatiques pour transmissions hydrauliques
Hydrospeicher für Hydraulikanwendungen This European Standard was approved by CEN on 18 September 2006 and includes Amendment 1 approved by CEN on 16 November 2010.
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, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre:
Avenue Marnix 17,
B-1000 Brussels © 2010 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 14359:2006+A1:2010: ESIST EN 14359:2007+A1:2011

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 C.1 EXAMPLE 1 . 79 C.2 EXAMPLE 2 . 80 C.3 EXAMPLE 3 . 81 C.4 EXAMPLE 4 . 82 C.5 EXAMPLE 5 . 83 C.6 EXAMPLE 6 . 84 SIST EN 14359:2007+A1:2011

Manufacturer's declaration of conformity form . 86 Annex E (informative)
!Example of 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 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" . 91 Annex G (informative)
Alternative relations for normal distributions . 95 Annex H (informative)
Variation coefficients of equipment material . 96 Annex I (informative)
!Quality / Severity condition of equipment / environment . 97 I.1 Equipment quality: ki values . 97 I.2 Severity conditions of environment: Ej values". 97 Annex ZA (informative)
Relationship between this European Standard and the Essential Requirements of EU Directive 97/23/EC . 98 Bibliography . 99
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, Bulgaria, Croatia, 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. SIST EN 14359:2007+A1:2011

(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 SIST EN 14359:2007+A1:2011

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=≥hinning=≤×ring=man×fac≥×ring=process=of=≥he=componen≥=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 MPab 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 MPab 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).
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. SIST EN 14359:2007+A1:2011

Figure 5.1 — Design process
5.4.2 Basic symbols, units and description Table 5.4-1 lists basic symbols and units. Further and modified notation is provided in the individual sections. Table 5.4-1 — Basic symbols and units Symbols Characteristics Units De Outside diameter of the shell mm Di Inside diameter of the shell mm es Required thickness of end to limit membrane stress in central part of shell mm ey Required thickness of knuckle to avoid axis-symmetric yielding mm f Nominal design stress at design temperature MPa a fa Nominal design stress at test temperature MPa a fshear Nominal design shear stress at design temperature = f x 0,8 MPa a ftest Nominal design stress for testing conditions MPa a h Internal height of dished end measured from cylindrical part mm r Inside radius of curvature of a knuckle mm R Inside spherical radius of central part of torispherical end mm a
MPa for calculation purposes only, otherwise the unit should be bar (1 MPa = 10 bar).
Normal Under test conditions Steels other than austenitic with
A < 30 % ⎟⎟⎠⎞⎜⎜⎝⎛=2,4;1,5 minm/20p0,2/tRRf 1,05testp0,2/ttestRf= Austenitic steels with
30 % < A ≤ 35 % 1,5p1,0/tRf= 1,05testp1,0/ttestRf= Austenitic steels with
A > 35 % ⎥⎥⎦⎤⎢⎢⎣⎡⎟⎟⎠⎞⎜⎜⎝⎛⎟⎟⎠⎞⎜⎜⎝⎛=3;1,2 min ;1,5maxm/tp1,0/tp1,0/tRRRf⎟⎟⎠⎞⎜⎜⎝⎛=2;1,05max testm/ttestp1,0/ttestRRf Cast steels ⎟⎟⎠⎞⎜⎜⎝⎛=3;1,9 minm/20p0,2/tRRf 1,33testp0,2/ttestRf=
NOTE Only
is valid for fine-grained steels and heat-treated steels. 5.5 Design and calculation methods common to all accumulator types 5.5.1 General All applicable equations shall be used in order to demonstrate conformity with this European Standard. The maximum allowable pressure PS can be replaced by the test pressure PT when calculating for test conditions. 5.5.2 Specific definitions 5.5.2.1 Cylinder right circular cylinder 5.5.2.2 Torispherical end dished end, made up of a spherical cap, a toroidal knuckle and a cylindrical shell, the three components having common tangents where they meet 5.5.2.3 Klöpper-type torispherical end for which R/De = 1,0 and r/De = 0,1 5.5.2.4 Korbbogen-type torispherical end for which R/De = 0,8 and r/De = 0,154 SIST EN 14359:2007+A1:2011

Figure 5.2 — Geometry for cylindrical shells
The required wall thickness e is given by: SiSPzf2DPe−⋅⋅=
(5.5-1) or SeSPzf2 DPe+⋅⋅= (5.5-2)
For a given geometry:
iea4SDDezfP+⋅⋅= (5.5-3)
NOTE The requirements of Equations 5.5-2 and 5.5-3 are valid for e/De not greater than 0,16. 5.5.4 Dished ends under internal pressure 5.5.4.1 Hemispherical ends
Figure 5.3 — Hemispherical end SIST EN 14359:2007+A1:2011

The required wall thickness e of a hemispherical end (or spherical shell) shall be calculated from one of the two following equations:
S4iSPzfDPe−⋅⋅⋅= (5.5-4) or S4eSPzfDPe+⋅⋅⋅= (5.5-5)
Shell thickness may be increased at junctions with other parts such as cylindrical shells or the torus of a torispherical end. Increased thickness may also be necessary to provide reinforcement at isolated openings. The thickness of the cylinder up to the tangent line shall be kept at or above the minimum of the required cylinder wall thickness. 5.5.4.2 Torispherical ends 5.5.4.2.1 General
Figure 5.4 — Torispherical end
5.5.4.2.2 Conditions of applicability The following requirements are limited in application to ends for which all of the following conditions are met: a) r
≤ 0,2 Di b) r
≥ 0,06 Di c) r
≥ 2e d) e
≤ 0,08 De e) ea
≥ 0,005 De f) R
≤ De SIST EN 14359:2007+A1:2011

(5.5-6)
()fDRPeiy2,075,0S⋅+⋅⋅= (5.5-7)
where
is found from the following equations: ()4,0;/eminRY= (5.5-8)
()YZ/1log10= (5.5-9)
i/DrX= (5.5-10)
()4902,61006,1YN⋅+−= (5.5-11)
For X = 0,06
()8873.12937,32124,23635,02306,0+−+−=ZZZN
For 0,06 < X < 0,1
()(){}1,006,006,01,025XX−+−=
For X = 0,1
()837,02943,10383,11833,0231,0+−+−=ZZZN
For 0,1 < X < 0,2
()(){}2,01,01,02,010XX−+−=
For X = 0,2
(){}5,0;5,8294,156,095,0ma•22,0YY−−=
(5.5-12) NOTE The above equations for
lead to an iterative calculation for which a computer procedure is recommended. 5.5.4.2.3 Special conditions for Klöpper-type ends R = De
r = 0,1 De
h = 0,193 5 De – 0,455 ea SIST EN 14359:2007+A1:2011

0,10,001ea≤≤De
(5.5-13) 5.5.4.2.4 Special conditions for Korbogen-type ends R = 0,8 De
r = 0,154 De
h = 0,255 De – 0,635 ea
0,10,001aa≤≤De (5.5-14) 5.5.5 Isolated openings and nozzles in spherical shells and spherical centre areas of dished ends 5.5.5.1 Specific symbols and units Table 5.5-1 lists further specific symbols and units. SIST EN 14359:2007+A1:2011

Table 5.5-1 — Specific symbols and units
Symbol Characteristics Unit a Distance taken along the average wall surface on the section where the reinforcement of an opening has to be calculated, between the opening centre and the external edge of a nozzle; if no nozzle is present, a is the distance between the centre and the internal edge of the opening mm Af Stress-loaded cross-sectional area effective as compensation mm2 Afb Af of a nozzle (b=branch) mm2 Afs Af of shell wall (main body) mm2 Afw Area of weld between nozzle and shell (only if outside the shell and nozzle shape, fillet weld) mm2 Ap Pressure-loaded area mm2 Aps Ap of shell (main body) mm2 Apb Ap of nozzle mm2 d Diameter (or maximum width) of opening, or inside diameter of nozzle mm deb Outside diameter of nozzle mm dib Inside diameter of nozzle mm ebk Required thickness of knuckle to avoid plastic buckling mm eb Required thickness of nozzle (or mean thickness within the length lbo or lbio) mm e´b Effective thickness of nozzle useful for reinforcement mm e´s Length of penetration of nozzle into shell wall for set-in nozzles with partial penetration mm ey Required thickness of knuckle to avoid axis-symmetric yielding mm fb f of nozzle MPaa fbk Nominal design stress for buckling equation MPaa fs f of shell material (main body) MPaa lb Length of nozzle extending outside the shell mm l´b Effective length of nozzle outside the shell, useful for reinforcement mm lbi Length of nozzle extending inside the shell mm l´bi Effective length of nozzle inside the shell, useful for reinforcement mm lbo Maximum length of nozzle outside the shell useful for reinforcement mm lbio Maximum length of nozzle inside the shell, useful for reinforcement mm l´s Effective length of shell, useful for opening reinforcement mm lso Maximum length of shell contributing to opening reinforcement taken on the mean radius of curvature of the shell wall mm ris Inside radius of curvature of the shell at the opening centre mm res Outside radius of curvature of the shell at the opening centre mm rms Mean radius of curvature of the shell at the opening centre mm a
MPa for calculation purposes only, otherwise the unit should be bar (1 MPa = 10 bar). 5.5.5.2 General All openings shall be isolated and circular with centrelines coaxial with the axis. For spherical shells and hemispherical or torispherical ends the following conditions shall be met. 0,6e;0,5is2≤≤⋅Ddrd (5.5-15)
Reinforcement is only permitted by increasing the wall thickness of the shell and/or a nozzle.
Nozzles may be ‘set-on’ or ‘set-in’ (see Figures 5.6 and 5.8). 5.5.5.3 Small openings If an isolated opening has a diameter d meeting the following condition: )(2s0,14seisred+⋅⋅⋅≤ (5.5-16) then the opening shall be considered a "small opening" and it needs no reinforcement. No further calculation is necessary. 5.5.5.4 Openings and nozzles used in accumulators
AfsApsrisrmsresesI'sdδ
debdibebApbAfsApsrisrmsresesI'sI'b < IboAfbIb_d Figure 5.5 — Reinforcement by wall thickness Figure 5.6— Reinforcement by Set-on nozzle (and wall thickness)
forged nozzle (and wall thickness) Figure 5.8 — Reinforcement by Set-in nozzle (and wall thickness)
5.5.5.5 Calculation procedure for openings in shells 5.5.5.5.1 Purpose The design method specified in this clause is applicable for a spherical shell or the spherical part of a torispherical end. The following conditions shall be satisfied:
)pbps(SS)0,5ob(fbS)0,5s()fwfs(AAPPfAPfAA+⋅≥⋅−⋅+⋅−⋅+ (5.5-17) )bsMIN(ff;fob= (5.5-18) For spherical shells: 2is2eisDeDr=−= (5.5-19)
For hemispherical or torispherical ends: Rr=is (5.5-20) For dished ends and spherical shells: isreal'rA+⋅+⋅⋅=s0,5s2is0,5sp (5.5-21) SIST EN 14359:2007+A1:2011

)arcsin(ms/ra⋅= (5.5-22) where s0,5ismserr⋅+= (5.5-23) ms2ebrd⋅=δ (5.5-24) Moreover: for set-in nozzles: sssl'eAf⋅= (5.5-25) for set-on nozzles: )l'(eeAsbssf+⋅= (5.5-26) 5.5.5.5.2 Reinforcement by increased wall thickness of the shell The length of shell l´s, contributing to reinforcement of the opening, taken from the edge of the opening or from the external diameter of a nozzle and along the mean surface of the shell, shall not be greater than lso.
()ssoisss'2llree≤=⋅+⋅⎡⎤⎣⎦ (5.5-27) 5.5.5.5.3 Reinforcement by increased nozzle thickness The reinforcement of an opening can be obtained by increasing the wall thickness of the nozzle above the minimum thickness required in order to withstand the internal pressure (see 5.5.3). This possibility is independent of any reinforcement provided by increasing the wall thickness of the shell.
The length contributing to the reinforcement shall not be greater than lso for the shell and not more than lbo for the nozzle, with:
()boebbbldee≤−⋅⎡⎤⎣⎦ (5.5-28)
for set-in nozzles and forged nozzles (l´bi=0):
)sbib(bbe'l'l'e'Af++⋅= (5.5-29)
for set-on nozzles: bbbl'e'Af⋅= (5.5-30) SIST EN 14359:2007+A1:2011

l´b = MIN (lbo; lb); l´bi = MIN (lbio; lbi); e´s is the length of penetration (full or part) of set-in nozzle into shell wall ( ≤es ); Apb = 0,5 · di · (l´b + es); Afs and Aps have already been defined in Table 5.5-1. SIST EN 14359:2007+A1:2011
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