1、September 2008DEUTSCHE NORM Translation by DIN-Sprachendienst.English price group 11No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards
2、(DIN-Normen).ICS 23.040.20!$R“1476104www.din.deDDIN 8078Polypropylene (PP) pipes PP-H, PP-B, PP-R, PP-RCT General quality requirements and testingRohre aus Polypropylen (PP) PP-H, PP-B, PP-R, PP-RCT Allgemeine Gteanforderungen, PrfungSupersedesDIN 8078:2007-05www.beuth.deDocument comprises 17 pagesI
3、n case of doubt, the German-language original should be consulted as the authoritative text.DIN 8078:2008-09 2 Contents Page Foreword3 1 Scope 4 2 Normative references 4 3 Material .4 3.1 General4 3.2 Proof of long-term hydrostatic strength .5 4 Requirements 10 4.1 Delivery condition. 10 4.2 Surface
4、 condition 10 4.3 Dimensions and tolerances. 10 4.4 Long-term hydrostatic strength 10 4.5 Impact strength test behaviour (inspection by attributes). 10 4.6 Changes after heat treatment 10 5 Testing . 11 5.1 Surface condition 11 5.2 Dimensions 11 5.3 Out-of-roundness (ovality). 11 5.4 Long-term hydro
5、static strength test. 12 5.5 Impact strength test (inspection by attributes) . 13 5.6 Heat reversion. 14 5.7 Inspection documents 14 Annex A (informative) Explanatory notes 15 Bibliography. 17 Figures Figure 1 Reference characteristic curves of the long-term hydrostatic strength (minimum curves) for
6、 PP-H pipes6 Figure 2 Reference characteristic curves of the long-term hydrostatic strength (minimum curves) for PP-B pipes7 Figure 3 Reference characteristic curves of the long-term hydrostatic strength (minimum curves) for PP-R pipes8 Figure 4 Reference characteristic curves of the long-term hydro
7、static strength (minimum curves) for PP-RCT pipes.9 Figure 5 Test pieces for long-term hydrostatic test. 12 Figure 6 Bar-shaped test piece for impact strength test . 13 Tables Table 1 Coefficients for calculating the reference characteristic curves5 Table 2 Test conditions for the long-term hydrosta
8、tic test 11 Table 3 Impact strength test pieces 14 Table 4 Test conditions for heat treatment . 14 Table A.1 Guideline values for some properties of PP materials . 16 DIN 8078:2008-09 3 Foreword This standard has been prepared by Technical Committee NA 054-05-02 AA Prfverfahren fr Rohre of the Norme
9、nausschuss Kunststoffe (Plastics Standards Committee). DIN, the German Institute for Standardization, would like to bring attention to the fact that complying with this standard can involve exploitation of Patent EP1448631 in regard to material PP-RCT. DIN takes no postition on the legitimacy, valid
10、ity or scope of this patent. The holder of this patent has declared to DIN he is prepared to negotiate with applicants from any part of the world licences under reasonable and non-discriminatory business conditions as laid down in his declaration. The declaration of the holder of patent EP 1448631 i
11、s registered with DIN. Information can be obtained from the patent holder at this address: Att: Managing Director Borealis Technology Oy | P.O. Box 330 | FI-06101 Porvoo | Finland Tel. +358 9 3949 00 e-mail: Attention is drawn to the possibility that some of the elements of this document may be the
12、 subject of patent rights. DIN shall not be held responsible for identifying any or all such patent rights. Amendments This standard differs from DIN 8078:1996-04 as follows: a) Type PP-RCT polypropylene has been included. b) The material designation has been modified. c) An equation for the referen
13、ce curves has been included. This standard differs from DIN 8078:2007-05 as follows: a) A reference to patent rights has been added to the Foreword. b) The description of PP-RCT polypropylene has been modified. c) A reference to existing European product standards has been added to the Scope. Previo
14、us editions DIN 8078-2:1980-05 DIN 8078: 1972-02, 1984-04, 1996-04, 2007-05 DIN 8078:2008-09 4 1 Scope This standard is applicable to circular-cross-section seamless polypropylene (PP) pipes made from homopolymer polypropylene (PP-H), block copolymer polypropylene (PP-B), random copolymer polypropyl
15、ene (PP-R) or random copolymer polypropylene with modified crystalline structure and elevated temperature resistance (PP-RCT). Individual requirements specified in this standard may be omitted or supplemented in technical delivery conditions relating to particular applications. Attention is brought
16、to the fact that existing European product standards apply for some specific applications, which are to be complied with where necessary. Some of these product standards are listed in the bibliography for the information of users of this standard. Please note that because European Standards are cont
17、inually being developed, this list is not exhaustive. 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 (includi
18、ng any amendments) applies. DIN 323-1, Preferred numbers and series of preferred numbers Basic values, calculated values, rounded values DIN 8077, Polypropylene (PP) pipes PP-H, PP-B, PP-R, PP-RCT Dimensions DIN 16887, Determination of the long-term hydrostatic pressure resistance of thermoplastics
19、pipes DIN EN 10204, Metallic products Types of inspection documents DIN EN ISO 179-1, Plastics Determination of Charpy impact properties Part 1: Non-instrumented impact test DIN EN ISO 1167-1, Thermoplastics pipes, fittings and assemblies for the conveyance of fluids Determination of the resistance
20、to internal pressure Part 1: General method DIN EN ISO 1167-2, Thermoplastics pipes, fittings and assemblies for the conveyance of fluids Determination of the resistance to internal pressure Part 2: Preparation of pipe test pieces DIN EN ISO 2505, Thermoplastics pipes Longitudinal reversion Test met
21、hods and parameters DIN EN ISO 9080, Plastics piping and ducting systems Determination of the long-term hydrostatic strength of thermoplastics materials in pipe form by extrapolation 3 Material 3.1 General Pipes shall be made from polypropylene (PP) moulding material stabilized with suitable antioxi
22、dants. The choice of stabilizers and other additives shall be left to the manufacturer. Moulding materials of unknown composition shall not be used (see Appendix A: Explanatory notes). DIN 8078:2008-09 5 3.2 Proof of long-term hydrostatic strength For PP-H, PP-B, PP-R and PP-RCT, it shall be proven
23、that the long-term hydrostatic strength lies on or above the corresponding reference characteristic curves (minimum curves), see Figure 1 to Figure 4. The proof shall be provided by means of a suitable method, for example, according to DIN EN ISO 9080 or DIN 16887 and shall take into account the tem
24、perature-time limits. The reference characteristic curves are based on equation (1). lglglg += DTCTBAt (1) where A, B, C and D are the coefficients according to Table 1; T is the temperature, in K; t is the time, in h. Table 1 Coefficients for calculating the reference characteristic curves Coeffici
25、ents Material Part of reference characteristic curveA B C D flat slope 46,364 9 601,1 20 381,5 15,24 PP-H steep slope 18,387 0 8 918,5 4,1 flat slope 56,086 10 157,8 23 971,7 13,32 PP-B steep slope 13,699 0 6 970,3 3,82 flat slope 55,725 9 484,1 25 502,2 6,39 PP-R steep slope 19,98 0 9 507 4,11 PP-R
26、CT flat slope 119,546 23 738,797 52 176,696 31,279 The coefficients given in Table 1 to describe the reference characteristic curves apply in the temperature range 10 C to 95 C for materials PP-H, PP-B and PP-R and in the temperature range 10 C to 110 C for material PP-RCT. DIN 8078:2008-09 6 Figure
27、 1 Reference characteristic curves of the long-term hydrostatic strength (minimum curves) for PP-H pipes DIN 8078:2008-09 7 Figure 2 Reference characteristic curves of the long-term hydrostatic strength (minimum curves) for PP-B pipes DIN 8078:2008-09 8 Figure 3 Reference characteristic curves of th
28、e long-term hydrostatic strength (minimum curves) for PP-R pipes DIN 8078:2008-09 9 Figure 4 Reference characteristic curves of the long-term hydrostatic strength (minimum curves) for PP-RCT pipes DIN 8078:2008-09 10 4 Requirements 4.1 Delivery condition The pipe ends should be as perpendicular as p
29、ossible to the pipe axis. The pipes shall be free of blisters, shrink holes and inhomogeneities that would impair their performance in service. They shall be of uniform colour throughout. 4.2 Surface condition The internal and external pipe surfaces shall be smooth. Slight corrugations and the resul
30、tant irregularities in the wall thickness are permitted provided the wall thickness does not go below the nominal values specified in DIN 8077. No sharp-edged grooves or sink marks are permitted. Testing shall be as specified in 5.1. 4.3 Dimensions and tolerances The dimensions and tolerances specif
31、ied in DIN 8077 apply for the outside diameters, wall thickness and out-of-roundness. Testing shall be as specified in 5.2 and 5.3. For pipes with special dimensions not covered in DIN standards as a result of deviations from preferred numbers (see DIN 323-1) and international specifications, the ca
32、lculation principles of DIN 8077 apply. 4.4 Long-term hydrostatic strength The long-term resistance to internal pressure shall be determined in a long-term hydrostatic strength test (5.4). The long-term hydrostatic strength test conditions are specified in Table 2. The pipes shall not leak or otherw
33、ise fail during the specified stressing period (failure time). 4.5 Impact strength test behaviour (inspection by attributes) When tested according to 5.5, the failure rate of the test pieces shall not exceed 10 %. 4.6 Changes after heat treatment When tested according to 5.6, the mean relative chang
34、e in length of the pipe shall not exceed 2 %. DIN 8078:2008-09 11 Table 2 Test conditions for the long-term hydrostatic test Test temperature Hoop stress Stressing period (failure time) Pipe material Environment (test medium) C 0 MPa t h Air or water 20 21 1 Air or water 95 4,2 165 Air or water 95 3
35、,5 1 000 PP-H Air 110 1,9 8 760a Air or water 20 16 1 Air or water 95 3,0 165 Air or water 95 2,6 1 000 PP-B Air 110 1,4 8 760aAir or water 20 16 1 Air or water 95 3,8 165 Air or water 95 3,5 1 000 PP-R Air 110 1,9 8 760aAir or water 20 15 1 Air or water 95 4,0 165 Air or water 95 3,8 1 000 PP-RCT A
36、ir 110 2,6 8 760aaQuality control for initial production, or change of material or manufacture. 5 Testing 5.1 Surface condition The internal and external surfaces of the pipe shall be examined against the light without optical aids. 5.2 Dimensions The mean outside diameter of the pipe shall be deter
37、mined to the nearest 0,1 mm at both ends of the pipe by measuring the circumference. The wall thicknesses of the pipe shall be determined to the nearest 0,1 mm at 4 points at each pipe end with the measurement points being distributed as uniformly as possible around the circumference of the pipe. Th
38、e measurements shall be carried out at (23 2) C. 5.3 Out-of-roundness (ovality) Out-of-roundness (the difference between the measured maximum outside diameter and the measured minimum outside diameter in the same cross-section of the pipe) shall be measured to the nearest 0,1 mm immediately after pr
39、oduction. DIN 8078:2008-09 12 5.4 Long-term hydrostatic strength test For general information on the test see DIN EN ISO 1167-1 and DIN EN ISO 1167-2. For each hoop stress as in Table 2, take three pipe sections (called “pipes” for short in the following) of the following lengths l1(see Figure 5): f
40、or d 250 mm: l1 3 d + 2 l5+ 250 mm for d 250 mm: l1 1 000 mm + 2 l5Figure 5 Test pieces for long-term hydrostatic test where d is the outside diameter of the pipe, in mm l1is the length of the test piece, in mm; l2is the test length, in mm; l3is the length of the zone affected by the end sealing dev
41、ices, in mm; for d 250 mm: l3= d for d 250 mm: l3= 250 mm l4is the assessment length, in mm; l4= l2 2 l3; l5is the length required for attaching the end cap, in mm. Measure the wall thickness e to the nearest 0,1 mm at eight points distributed along l4, and the outside diameter d to the nearest 0,1
42、mm by measuring the pipe circumference at three points, and then determine the minimum wall thickness eminand mean outside diameter dm. Fit the pipe with caps at both ends. It shall remain free to move in the axial direction during the test. Fill the pipe with water at the test temperature specified
43、 in Table 2 (tolerance: 5 K) through an aperture in one of the caps and place it in a bath heated to the test temperature (tolerance: 1 K) for at least 1 h until the temperature is constant. If the pipe is filled with water at a lower temperature, leave it in the bath for 12 h to ensure thermal equi
44、librium. Then, steadily increase the pressure in the pipe in the bath so that the specified test pressure is reached within 1 minute. Maintain the test pressure to within 2,5 % for the stressing period specified in Table 2. Calculate the test pressure pe,pusing equation (2): DIN 8078:2008-09 13 min0
45、minpe,2edep=(2) where d is the mean outside diameter over l4, in mm, eminis the minimum wall thickness over l4, in mm, 0is the hoop stress specified in Table 1, in MPa. Determine whether the pipe has leaked or otherwise failed during the specified stressing period. Tests in which the pipe has failed
46、 within l3during the stressing period are not to be evaluated and shall be repeated. 5.5 Impact strength test (inspection by attributes) Pipe sections or bar-shaped test pieces in the longitudinal direction (see Figure 6) shall be taken from the pipes according to the data in Table 3. The bar-shaped
47、 test pieces shall be taken from pipe sections (50 1) mm or (120 2) mm long from points spaced as uniformly as possible around the circumference. The test piece width given in Table 2 corresponds to chord length b of the circular cut-out both of the external and internal pipe wall (see Figure 6). Th
48、e pipe surfaces of the test pieces shall not be machined if the wall thickness e 10,5 mm. For test pieces from pipes with wall thicknesses greater than 10,5 mm, the external pipe surface shall be machined down to a thickness of (10 0,5) mm. The machined surface shall be smoothed with emery paper (gr
49、ain size No. 220 or finer) in the longitudinal direction. Figure 6 Bar-shaped test piece for impact strength test The impact strength test shall be carried out according to DIN EN ISO 179-1 on 10 test pieces using a 15 J pendulum impact testing machine with the blow being applied to the external pipe surface or the machined side. The test shall be carried out at (23 2) C for pipes made from PP-H and at (0 2) C for pipes made from PP
