1、BRITISH STANDARDBS EN14741:2006Thermoplastics piping and ducting systems Joints for buried non-pressure applications Test method for the long-term sealing performance of joints with elastomeric seals by estimating the sealing pressureThe European Standard EN 14741:2006 has the status of a British St
2、andardICS 23.040.80g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN 14741:2006This British Standard was published under the authority of the St
3、andards Policy and Strategy Committee on 30 June 2006 BSI 2006ISBN 0 580 48492 0National forewordThis British Standard is the official English language version of EN 14741:2006.The UK participation in its preparation was entrusted by Technical Committee PRI/88, Plastic piping systems, to Subcommitte
4、e PRI/88/4, Test methods, which has the responsibility to: A list of organizations represented on this subcommittee can be obtained on request to its secretary.Cross-referencesThe British Standards which implement international or European publications referred to in this document may be found in th
5、e BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online.This publication does not purport to include all the necessary provisions of a contract. Users are responsible f
6、or its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep UK intere
7、sts informed; monitor related international and European developments and promulgate them in the UK.Summary of pagesThis document comprises a front cover, an inside front cover, the EN title page, pages 2 to 15 and a back cover.The BSI copyright notice displayed in this document indicates when the d
8、ocument was last issued.Amendments issued since publicationAmd. No. Date CommentsEUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 14741February 2006ICS 23.040.80English VersionThermoplastics piping and ducting systems - Joints for buriednon-pressure applications - Test method for the long-termseali
9、ng performance of joints with elastomeric seals byestimating the sealing pressureSystmes de canalisations et de gaines enthermoplastiques - Assemblages pour applicationsenterres sans pression - Mthode dessai pour laperformance long terme des assemblages avecgarnitures dtanchit en lastomre par lestim
10、ation de lapression dtanchitRohrleitungs- und Schutzrohrsysteme aus Thermoplasten -Verbindungen fr erdverlegte drucklose Anwendungen -Prfverfahren fr das Langzeit-Dichtverhalten vonVerbindungen mit Elastomer-dichtungen durchAbschtzung des DichtdrucksThis European Standard was approved by CEN on 30 D
11、ecember 2005.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 ob
12、tained 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 Secr
13、etariat 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, Portu
14、gal, Romania,Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2006 CEN All rights of exploitation in any form and by any means res
15、ervedworldwide for CEN national Members.Ref. No. EN 14741:2006: EEN 14741:2006 (E) 2 Contents Foreword .3 1 Scope .4 2 Normative references4 3 Symbols .4 4 Principle.5 5 Apparatus 5 6 Test pieces.6 7 Test procedure 7 8 Calculation and expression of the results.8 9 Test report .10 Annex A (informativ
16、e) Example of a tube manufacturers specification 12 Annex B (informative) Description of a training test assembly .13 EN 14741:2006 (E) 3 Foreword This European Standard (EN 14741:2006) has been prepared by Technical Committee CEN/TC 155 “Plastics piping systems and ducting systems”, the secretariat
17、 of which is held by NEN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by August 2006, and conflicting national standards shall be withdrawn at the latest by August 2006. The material-dependent pa
18、rameters and/or performance requirements are incorporated in the System Standard(s) concerned. This standard is one of a series of standards on test methods that support System Standards for plastics piping systems and ducting systems. According to the CEN/CENELEC Internal Regulations, the national
19、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, Portuga
20、l, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EN 14741:2006 (E) 4 1 Scope This draft European Standard specifies a method for determination of the long-term sealing pressure of elastomeric seals in assembled joints for buried non-pressure sewerage plastics piping and
21、 ducting systems. 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 681-1
22、, Elastomeric seals Materials requirements for pipe joint seals used in water and drainage applications Part 1: Vulcanized rubber EN 681-2, Elastomeric seals Materials requirements for pipe joint seals used in water and drainage applications Part 2: Thermoplastic elastomers EN 681-3, Elastomeric sea
23、ls Materials requirements for pipe joint seals used in water and drainage applications Part 3: Cellular materials of vulcanized rubber EN 681-4, Elastomeric seals Materials requirements for pipe joint seals used in water and drainage applications Part 4: Cast polyurethane sealing elements EN 837-1:1
24、996, Pressure gauges Part 1: Bourdon tube pressure gauges Dimensions, metrology, requirements and testing EN ISO 9967, Plastics pipes - Determination of creep ratio (ISO 9967:1994) 3 Symbols B : the theoretical pressure in bar, in the PTFE tube at t = 1 h D : drop factor of extrapolated pressure dat
25、a at 24 h and 100 years M : the gradient of the curve pt: pressure measured in the PTFE tube at a flow of 120 ml/min and the time t hours p0: initial leakage pressure in bar, measured in the PTFE tube after completing the assembly pta, ptb, ptc: pressure measured in the 3 PTFE tubes in the tested jo
26、int marked a, b or c respectively at the time t hours px: extrapolated pressure in bar at 100 years py: calculated pressure in bar at 24 h pxa, pxb, pxc: extrapolated pressure in bar at 100 years in the 3 PTFE tubes in the tested joint marked a, b or c respectively. p100 y: the arithmetic mean value
27、 of the pressures obtained for each of the three extrapolated values pxat 100 years EN 14741:2006 (E) 5 p24 h: the arithmetic mean value of the pressures obtained for each of the three calculated values pyat 24 h R : correlation coefficient t : time in hours 4 Principle The sealing pressure in a joi
28、nt is estimated by measuring the pressure, necessary to lift the seal, in each of 3 PTFE tubes equally distributed over the circumference of a joint located between the rubber seal and the spigot or socket as appropriate, see Figure 1. In a temperature controlled environment and at increasing time i
29、ntervals, a constant flow rate of 120 ml/min nitrogen or air is forced through 3 flexible PTFE tubes. The nitrogen or air pressure p, necessary to achieve this flow, is measured. The pressure ptis measured at increasing time intervals over a period of time. The extrapolated regression lines for pt a
30、re used to calculate the estimated value pxat 100 years and pyat 24 h. 5 Apparatus Key A Source of nitrogen or clean air F Position of the tube in a joint with the sealing ring positioned on the spigot B Regulator/pressure controller G Test assembly base C Pressure gauge H Position of the tube in a
31、joint with sealing ring positioned in the socket D Fixed coupler J Connecting tube E PTFE tube K Flow meter Figure 1 Typical arrangement of the test assembly EN 14741:2006 (E) 6 5.1 A source of nitrogen, with a purity of at least 99,8%, or alternatively, cleaned air (oil free) both capable of supply
32、ing a flow of up to 200 ml/min and at a pressure of at least 10 bar 1. 5.2 Regulator/pressure controller, capable of regulating a stable pressure and flow increase up to 120 ml/min. 5.3 Pressure gauge, for measuring the pressure in the main line and capable of checking conformity to 7.2 (class 0,6 o
33、r better as specified in EN 837-1:1996). 5.4 Connecting tube, with an inside diameter of at least 4 mm. 5.5 PTFE tube, conforming to the following: capable of sustaining at least 10 bar pressure. the total thickness of the flattened PTFE tube shall be between 0,16 mm and 0,24 mm, measured in the mid
34、dle of the sample and carried out in two positions perpendicular to each other. the total width of the flattened tube shall be between 6 mm and 10 mm. NOTE The PTFE tube used for this test is a blown-up tube, normally applied as a shrinkage tube. The original diameter and wall thickness after shrink
35、age are normally specified. The attention is drawn that the blown-up dimensions are normally not specified. Care should be taken that the wall thickness and the diameter of the tube as received are verified. The given tolerances should be seen as a guide for the supplier. 5.6 Flow meter, with a capa
36、city of 200 ml/min and a tolerance of 5 ml/min 5.7 Means for storage of the test assembly, capable of fixing and storing the test assembly in such a way that no additional movements in the joint can occur. It shall be capable of fixing the PTFE tubes in such a way that during connecting or disconnec
37、ting to the pressure gauge and flow meter, no movement of the PTFE tube in the sealing area can occur. 5.8 Lubricant, an aerosol of silicon (Polydimethylsiloxanoil) with gas propellant (Propane/Butane). 6 Test pieces 6.1 General Each test piece shall consist of a complete joint, together with its el
38、astomeric seal and PTFE tube(s). Unless otherwise specified in the referring standard, the number of PTFE tubes shall be three, marked as a, b and c, equally spaced around the spigot. 6.2 Assembly Prior to assembly, the test pieces shall be conditioned at the test temperature for at least 24 h. Clea
39、n the rubber sealing ring, the socket and the spigot. Prepare the PTFE tube by pressing it together several times until permanently flattened and place it along the smooth surface of the spigot or socket. 11 bar = 105N/m2EN 14741:2006 (E) 7 Lubricate the smooth wall in the joint (spigot or socket),
40、the seal and PTFE tube(s). The lubricant as defined in 5.8 shall be used. Use sufficient lubricant to ensure that the PTFE shrinkage tube(s) and seal can be assembled without damage, and the seal can equalise its position within the groove circumference. Assemble the socket and spigot, including the
41、 seal, in accordance with the manufacturers instructions and the following requirements. a) The joint shall be assembled in such a way that the PTFE tubes are mounted between the spigot or socket and the seal (see Figure 1); precaution shall be taken to avoid squeezing of the PTFE tube outside the s
42、ealing area. It is permitted to mill a grove, insert thin plastics strips along the tube, drill holes in the spigot or socket or any other method to give room for sufficient flow through the tube outside the sealing area. The method selected shall not significantly influence the creep behaviour of t
43、he joint in the sealing housing area. b) Make sure that the PTFE tube can move freely in the axial direction and that the flattened section of the PTFE tube is located under the sealing ring and not distorted, when the joint is made. 6.3 Leaktightness of the test system Make sure the pressurised sid
44、e of the test equipment is leaktight after installation. Identify any leakage by soap solution. If necessary, reassemble the leaking joints. Avoid flow through the sealing zone during this operation. 7 Test procedure 7.1 General The testing shall start between half an hour and 8 h after assembly and
45、 leaktightness testing in accordance with Clause 6. For each of the installed PTFE tubes, carry out the procedure according to 7.2 with the test pieces kept in the temperature controlled environment at (23 2) C. Measure and record the sealing pressure, p in bar, at times of 24 h, 168 h, 336 h, 504 h
46、, 600 h, 696 h, 862 h, 1008 h, 1392 h and 2000 h. Where it is not possible to read the pressure at the appropriate time between 500 h and 2000 h, it is permitted to deviate by up to 48 h, provided the actual measurement time is used in preparing the plots described in Clause 8. 7.2 Procedure for det
47、ermining the pressure 7.2.1 Measure the leakage pressure, p0, in each of the 3 tubes individually, using the following procedure. a) Using the procedure described in 7.2.2 a) steadily increase pressure until a flow of 120 ml/min through the PTFE tube occurs; b) Measure and record this initial leakag
48、e pressure p0; c) Reduce pressure to zero. 7.2.2 At each time interval as specified in 7.1, achieve a flow of 120 ml/min and measure and record the nitrogen (or air) pressure ptin bar, using the following procedure for each of the 3 tubes individually. EN 14741:2006 (E) 8 a) Increase pressure in inc
49、rements of 0,5 bar until the level is 0,5 bar below p0or the previous measurement. Then continue and increase the pressure gradually and slowly. Occasionally allow time to stabilise the pressure and flow. Continue this process until the flow rate has been (120 5) ml/min for 60 s at the same pressure. Record the pressure as ptain bar. In the case of pressure reaching 10 bar stop pressurising and record the pressure as 10 bar. If the pressure in all three tubes is recorded as 10 bar after the reading at 504 h, the assembly
