1、Hardware for furniture Tapered pressure tubes for self-supporting gas springs for the height adjustment of seating Test methods and requirements for strength and durabilityBS EN 16955:2017BSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06EUROPEAN STANDARD NORME EUROPEN
2、NE EUROPISCHE NORM EN 16955 April 2017 ICS 97.140 English Version Hardware for furniture - Tapered pressure tubes for self-supporting gas springs for the height adjustment of seating - Test methods and requirements for strength and durability Quincaillerie dameublement - Tubes coniques sous pression
3、 pour vrins gaz autoportants pour lajustement de la hauteur de sige - Mthodes et exigences dessai pour la rsistance et la durabilit Mbelbauteile - Konische Druckrohre fr selbsttragende Gasfedern zur Hhenverstellung von Sitzmbeln - Prfmethoden und Anforderungen fr die Festigkeit und Dauerhaltbarkeit
4、This European Standard was approved by CEN on 15 February 2017. 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 re
5、ferences 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
6、CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedo
7、nia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATI
8、ON EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2017 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 16955:2017 ENational forewordThis British Standard is the UK implementation of
9、EN 16955:2017.The UK participation in its preparation was entrusted by Technical Committee FW/0, Furniture, to Subcommittee FW/0/1, Common Test Methods for Furniture.A list of organizations represented on this subcommittee can be obtained on request to its secretary.This publication does not purport
10、 to include all the necessary provisions of a contract. Users are responsible for its correct application.ISBN 978 0 580 92177 3ICS 97.140Compliance with a British Standard cannot confer immunity from legal obligations. This British Standard was published under the authority of the Standards Policy
11、and Strategy Committee on 31 August 2017.Amendments/corrigenda issued since publicationDate Text affected BRITISH STANDARDBS EN 16955:2017EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 16955 April 2017 ICS 97.140 English Version Hardware for furniture - Tapered pressure tubes for self-supporti
12、ng gas springs for the height adjustment of seating - Test methods and requirements for strength and durability Quincaillerie dameublement - Tubes coniques sous pression pour vrins gaz autoportants pour lajustement de la hauteur de sige - Mthodes et exigences dessai pour la rsistance et la durabilit
13、 Mbelbauteile - Konische Druckrohre fr selbsttragende Gasfedern zur Hhenverstellung von Sitzmbeln - Prfmethoden und Anforderungen fr die Festigkeit und Dauerhaltbarkeit This European Standard was approved by CEN on 15 February 2017. CEN members are bound to comply with the CEN/CENELEC Internal Regul
14、ations 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 membe
15、r. 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. CE
16、N members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland,
17、Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2017 CEN All rights of exploitat
18、ion in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 16955:2017 EBS EN 16955:2017EN 16955:2017 (E) 2 Contents Page European foreword . 3 1 Scope 4 2 Normative references 4 3 Terms and definitions . 4 4 Strength classes for pressure tubes 4 5 Test apparatus 5 5.1
19、Material testing machine 5 5.2 Testing equipment for magnetic powder flaw test . 5 6 Test . 5 6.1 General 5 6.2 Strength and durability . 5 6.2.1 Sampling . 5 6.2.2 Test procedure . 5 6.2.3 Evaluation and requirement . 7 7 Test report . 7 8 Marking of the pressure tube . 8 Annex A (normative) Produc
20、t information . 9 A.1 General 9 A.2 Provisions 9 A.3 Marking on the gas spring 9 A.4 Gas spring activation 9 A.5 Connection between pressure tube and the seat mechanism. 9 A.6 Holding cone on the seat mechanism 10 Annex B (informative) Guide for choosing the correct strength class . 11 B.1 General .
21、 11 B.2 User weight . 11 B.3 Dimension u . 11 B.4 Choosing the correct gas spring 11 B.5 Recommendations for gas springs outside specifications in Table B.1 12 BS EN 16955:2017EN 16955:2017 (E) 3 European foreword This document (EN 16955:2017) has been prepared by Technical Committee CEN/TC 207 “Fur
22、niture”, the secretariat of which is held by UNI. 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 October 2017, and conflicting national standards shall be withdrawn at the latest by October 2017.
23、 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. According to the CEN-CENELEC Internal Regulations, the national standards organisations of the follo
24、wing countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, N
25、orway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. BS EN 16955:2017EN 16955:2017 (E) 4 1 Scope This European Standard specifies test methods and requirements for the strength and durability of tapered pressure tubes for self-suppo
26、rting gas springs for the height adjustment of seating. Annex A (normative) contains product information. Annex B (informative) contains a guide for choosing the correct strength class. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document a
27、nd are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN ISO 4288, Geometrical product specifications (GPS) - Surface texture: Profile method - Rules an
28、d procedures for the assessment of surface texture (ISO 4288) EN ISO 7500-1:2016, Metallic materials - Verification of static uniaxial testing machines - Part 1: Tension/compression testing machines - Verification and calibration of the force-measuring system (ISO 7500-1) EN ISO 9934-2, Non-destruct
29、ive testing - Magnetic particle testing - Part 2: Detection media (ISO 9934-2) ISO 1099, Metallic materials Fatigue testing Axial force-controlled method 3 Terms and definitions Not applicable. 4 Strength classes for pressure tubes The determination of the strength classes is based on characteristic
30、s given in Table 1. The dimension u of the seating is given in Figure 1. Table 1 Strength classes for pressure tubes Strength classaAlternate bending moment Largest distance between load bearing structure of the seat and centre of the column M u Nm mm 2 190 340 3 210 370 4 240 400 aDue to increased
31、requirements, strength class 1 is not part of this European Standard. BS EN 16955:2017EN 16955:2017 (E) 5 Key A mid of centre column u largest distance between load bearing structure of the seat and centre of the column Figure 1 Largest distance u between load bearing structure of the seat and centr
32、e of the column 5 Test apparatus 5.1 Material testing machine A material testing machine capable of performing tests in accordance with ISO 1099 shall be used. The testing machine force measuring system shall be verified statically in accordance with EN ISO 7500-1:2016, Class 1. 5.2 Testing equipmen
33、t for magnetic powder flaw test A testing equipment for magnetic powder flaw test for the particle inspection for the detection of surface imperfections shall be used. 6 Test 6.1 General For each combination of dimensions, production procedure, surface finish, materials or condition of the material
34、or any other characteristic which affects the strength and durability, a separate test shall be conducted. 6.2 Strength and durability 6.2.1 Sampling The test samples shall consist of 32 pressure tubes taken on a random basis from the series production. Any kind of marking on the pressure tube shall
35、 be done before strength and durability test. 6.2.2 Test procedure 6.2.2.1 Test setup The test setup is shown in Figure 2. BS EN 16955:2017EN 16955:2017 (E) 6 The end of the pressure tube shall be firmly fixed to the element which applies the load. If the element which applies the load is secured ag
36、ainst coming loose by a counter-cone on the internal side of the pressure tube the free bending length l5shall be at least 50 % of the overlap l3(see Figure 2). The free length l4between the upper and lower clamps shall be at least 50 mm. If there are series-produced shapings, embossings etc. in the
37、 area of the bearing length of the pressure tube, these areas shall be included in the tests so that they are in the compression-tension zone. Exceptions to this are pressure tubes with shapings, embossings etc. which are up to 60 mm away from the lower end of the pressure tube. Dimensions in millim
38、etres Key 1 counter-cone 2 element which applies the load 3 shapings and embossings permitted in this area without testing 4 lower clamp 5 pressure tube l3 length of connection between the holding cone and the pressure tube cone l4 free length between upper and lower clamp l5 free bending length F t
39、est load Tolerances: 0,5 mm of the nominal dimensions, unless otherwise stated Figure 2 Test setup for strength and durability BS EN 16955:2017EN 16955:2017 (E) 7 6.2.2.2 Test procedure The test shall be performed according to ISO 1099. The alternate bending moment M shall be as specified in Table 1
40、. It shall act in parallel to the longitudinal axis of the pressure tube. The length of the lever arm which applies the force is (150 5) mm. The time characteristic of the test force shall be sinusoidal. The stress cycle frequency shall not exceed 30 Hz. The alternate bending stress shall be applied
41、 with stress regulation. The temperature of the test piece shall not exceed 50 C during the test. To determine the strength and durability, the alternate bending stresses shall be applied in 2 106cycles and a mean stress of 0. 6.2.3 Evaluation and requirement After the test, the surfaces of the test
42、 pieces shall be subjected to a magnetic powder flaw test over their entire length and their entire circumference. The magnetic powder flaw test shall be performed on pressure tubes made of unalloyed and low-alloyed steels with alternating current magnetization. The test areas shall be cleaned and f
43、ree of interfering impurities. Suitable test apparatus shall be used to ensure that a tangential field strength of at least 2 kA/m is achieved. Wet test media shall be used for the test. The particle size of the magnetic powder shall be according to EN ISO 9934-2. Only carrier liquids which do not c
44、ause any corrosion to the subject of the test shall be used. If oil is used as a carrier agent, the sort selected shall be easily removed and leave no interfering residue. Marked test oils are suitable. If water is used as a carrier agent, it can be necessary to use additives to ensure that the surf
45、ace is properly wet (amount according to manufacturers instructions). The detection sensibility shall not be impaired by these additives. The test is deemed to have been passed if no cracks or fractures are seen on any of the 32 pressure tubes tested. 7 Test report Each type test shall be documented
46、 in a test report. The test report shall contain at least the following information: address of testing laboratory; date of testing; date of production of the pressure tubes; full description of the pressure tubes (e.g. type, material, surface finish, dimensions); manufacturer of the pressure tubes;
47、 dimensions of the test fixture (according to the details supplied by the manufacturer of the pressure tubes); overlap l3in test fixture; alternate bending moment and the strength class; BS EN 16955:2017EN 16955:2017 (E) 8 cycle frequency; documentation of the test equipment and the test setup; cond
48、ition of the test pieces after the magnetic powder flaw test (fracture, visible crack lengths). 8 Marking of the pressure tube The following shall be marked indelibly in a clearly visible place on each pressure tube: manufacturer; type designation of the manufacturer; reference to this European Stan
49、dard and strength class (according to Table 1) (e.g. EN 16955-2). BS EN 16955:2017EN 16955:2017 (E) 9 Annex A (normative) Product information A.1 General Product information shall be given to all subsequent producers. A.2 Provisions The pressure tube will perform its full function in regard to the relevant strength class (Table 1) only when all requirements of this European standard are fulfilled. A.3 Marking on the gas spring When implemented, the gas spring shall be marked visibly wit
