1、 DEUTSCHE NORMMay 2006DIN EN 14741 ICS 23.040.80 Supersedes DIN EN 1989:2000-04 Thermoplastics 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 pressure English version
2、of DIN EN 14741:2006-05 Rohrleitungs- und Schutzrohrsysteme aus Thermoplasten Verbindungen fr erdverlegte drucklose Anwendungen Prfverfahren fr das Langzeit-Dichtverhalten von Verbindungen mit Elastomer-Dichtungen durch Abschtzung des Dichtdrucks Englische Fassung DIN EN 14741:2006-05 Document compr
3、ises 17 pages No part of this standard may be reproduced without prior permission of DIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany, has the exclusive right of sale for German Standards (DIN-Normen). English price group 10 www.din.de www.beuth.de !,nh/“10.0
4、6 9756912DIN EN 14741:2006-05 2 National foreword This standard has been prepared by CEN/TC 155 Plastics piping systems and ducting systems (Secretariat: The Netherlands). The responsible German body involved in its preparation was the Normenausschuss Kunststoffe (Plastics Standards Committee), Tech
5、nical Committee 054-05-02 AA Prfverfahren fr Rohre. Amendments This standard differs from DIN EN 1989:2000-04 as follows: a) The standard has been completely revised. b) The test procedure is now based on estimating the sealing pressure in a joint by measuring the pressure required to lift the seal
6、in PTFE tubes which are equally distributed over the circumference of a joint located between the rubber seal and the outer wall of the spigot or socket. Previous editions DIN EN 1989:2000-04 EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 14741 February 2006 ICS 23.040.80 English Version Therm
7、oplastics 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 pressure Systmes de canalisations et de gaines en thermoplastiques - Assemblages pour applications enterre
8、s sans pression - Mthode dessai pour la performance long terme des assemblages avec garnitures dtanchit en lastomre par lestimation de la pression dtanchit Rohrleitungs- und Schutzrohrsysteme aus Thermoplasten -Verbindungen fr erdverlegte drucklose Anwendungen - Prfverfahren fr das Langzeit-Dichtver
9、halten von Verbindungen mit Elastomer-Dichtungen durch Abschtzung des Dichtdrucks This European Standard was approved by CEN on 30 December 2005. 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
10、 national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards 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
11、in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia,
12、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 COMIT EUROPEN DE NORMALISATION EUROPISCH
13、ES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2006 CEN All rights of exploitation in any form and by any means reserved worldwide 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
14、 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 (informative) Example of a tube manufacturers specification 12 Annex B (informative) Description of a training test assembly .13 PageEN 14741:2006 (E) 3 Foreword Th
15、is European Standard (EN 14741:2006) has been prepared by Technical Committee CEN/TC 155 “Plastics piping systems and ducting systems”, the secretariat 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 e
16、ndorsement, at the latest by August 2006, and conflicting national standards shall be withdrawn at the latest by August 2006. The material-dependent parameters and/or performance requirements are incorporated in the System Standard(s) concerned. This standard is one of a series of standards on test
17、methods that support System Standards for plastics piping systems and ducting systems. 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,
18、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 14741:2006 (E) 4 1 Scope This draft European Standard specifies a m
19、ethod for determination of the long-term sealing pressure of elastomeric seals in assembled joints for buried non-pressure sewerage plastics piping and ducting systems. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated referen
20、ces, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 681-1, Elastomeric seals Materials requirements for pipe joint seals used in water and drainage applications Part 1: Vulcanized rubber EN 681-2, Elastomer
21、ic seals Materials requirements for pipe joint seals used in water and drainage applications Part 2: Thermoplastic elastomers EN 681-3, Elastomeric seals Materials requirements for pipe joint seals used in water and drainage applications Part 3: Cellular materials of vulcanized rubber EN 681-4, Elas
22、tomeric seals Materials requirements for pipe joint seals used in water and drainage applications Part 4: Cast polyurethane sealing elements EN 837-1:1996, Pressure gauges Part 1: Bourdon tube pressure gauges Dimensions, metrology, requirements and testing EN ISO 9967, Plastics pipes - Determination
23、 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 data 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
24、 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 joint 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,
25、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 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 press
26、ures 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 joint 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
27、located between the rubber seal and the spigot or socket as appropriate, see Figure 1. In a temperature controlled environment and at increasing time intervals, 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 ac
28、hieve this flow, is measured. The pressure ptis measured at increasing time intervals over a period of time. The extrapolated regression lines for pt are 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
29、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 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
30、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 supplying 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
31、 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 or 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: c
32、apable 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 middle 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
33、. 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 shrinkage are normally specified. The attention is drawn that the blown-up dimensions are normally not specified. Care should be taken that the wall thickn
34、ess 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 capacity 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
35、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 disconnecting 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 (Polydime
36、thylsiloxanoil) with gas propellant (Propane/Butane). 6 Test pieces 6.1 General Each test piece shall consist of a complete joint, together with its elastomeric 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,
37、 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. Clean the rubber sealing ring, the socket and the spigot. Prepare the PTFE tube by pressing it together several times until permanently flattened and pla
38、ce 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), 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
39、 can be assembled without damage, and the seal can equalise its position within the groove circumference. Assemble the socket and spigot, including the seal, in accordance with the manufacturers instructions and the following requirements. a) The joint shall be assembled in such a way that the PTFE
40、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 sealing 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
41、give room for sufficient flow through the tube outside the sealing area. The method selected shall not significantly influence the creep behaviour of the 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 PT
42、FE 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 side of the test equipment is leaktight after installation. Identify any leakage by soap solution. If necessary, reassemble the leaking joints. Avoid fl
43、ow 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 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 piec
44、es 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, 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
45、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 determining the pressure 7.2.1 Measure the leakage pressure, p0, in each of the 3 tubes individually, using the following procedure. a) Using the proced
46、ure 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 leakage 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 n
47、itrogen (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 increments 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. Occa
48、sionally 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 a
49、ll three tubes is recorded as 10 bar after the reading at 504 h, the assembly shall be deemed to have passed the requirements. If one or two of the tubes show pressure less than 10 bar at the 504 h reading the test shall be continued and the calculation shall be done based on the pressure readings below 10 bar. b) Reduce pressure to zero. c) If during testing the actual flow reaches a level 10 % higher than 120 ml/min, stop the test and repeat the whole procedure after waiting for at least 30 min. 8 Calculatio
