BS-EN-448-2003.pdf

BRITISH STANDARD BS EN 448:2003 District heating pipes Preinsulated bonded pipe systems for directly buried hot water networks Fitting assemblies of steel service pipes, polyurethane thermal insulation and outer casing of polyethylene The European Standard EN 448:2003 has the status of a British Standard ICS 23.040.40 ? Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 04 07:47:49 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN 448:2003 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 27 February 2003 © BSI 27 February 2003 ISBN 0 580 41316 0 National foreword This British Standard is the official English language version of EN 448:2003. It supersedes BS EN 448:1995 which is withdrawn. The UK participation in its preparation was entrusted by Technical Committee RHE/9, Thermal insulating materials, to Subcommittee RHE/9/3, Insulation of underground pipelines, which has the responsibility to: A list of organizations represented on this subcommittee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the 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 for 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 the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 28, an inside back cover and a back cover. The BSI copyright date displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. DateComments Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 04 07:47:49 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM EN 448 February 2003 ICS 23.040.40Supersedes EN 448:1994 English version District heating pipes - Preinsulated bonded pipe systems for directly buried hot water networks - Fitting assemblies of steel service pipes, polyurethane thermal insulation and outer casing of polyethylene Tuyaux de chauffage urbain - Systèmes bloqués de tuyaux pré-isolés pour les réseaux d'eau chaude enterrés directement - Raccords pré-isolés en acier pour tubes de service en acier, isolation thermique en polyuréthane et tube de protection en polyéthylène Fernwärmerohre - Werkmäßig gedämmte Verbundmantelrohrsysteme für direkt erdverlegte Fernwärmenetze - Verbund-Formstücke, bestehend aus Stahl-Mediumrohr, Polyurethan-Wärmedämmung und Außenmantel aus Polyethylen This European Standard was approved by CEN on 28 November 2002. 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 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 Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Slovak Republic, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels © 2003 CENAll rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 448:2003 E Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 04 07:47:49 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 448:2003 (E) 2 Contents page Foreword4 Introduction.5 1Scope 6 2Normative references 6 3Terms and definitions7 4Requirements.8 4.1Steel parts.8 4.1.1Quality.8 4.1.2Wall thickness and diameter.8 4.1.3Bends8 4.1.4T-pieces.9 4.1.5Reducers.9 4.1.6Anchors.9 4.1.7Fusion welding of steel fittings10 4.1.8Surface condition.12 4.2Casing.12 4.3Polyurethane rigid foam insulation (PUR).12 4.4Fitting assemblies12 4.4.1Fitting ends.12 4.4.2Angle between casing segments of bend and minimum length.13 4.4.3Requirements of polyethylene welding.13 4.4.4Leak-tightness of the welded casing pipe.15 4.4.5Increase in diameter of the casing pipe 16 4.4.6Minimum insulation thickness in bends16 4.4.7Tolerances of the main fitting dimensions16 5Test methods17 5.1General17 5.2Test specimens17 5.3Steel parts.17 5.3.1Visual surface examination of welds.17 5.3.2Leak-tightness test with water17 5.3.3Leak-tightness test with air.17 5.3.4Radiographic examination of butt welds.18 5.4Casing.18 5.5Polyurethane rigid foam insulation (PUR).18 5.6Fitting assemblies18 5.6.1Centre line deviation and angular deviation.18 5.6.2Visual examination of welds on casing pipes.18 5.6.3Bending test .18 5.6.4Increase in diameter of the casing pipe 19 5.6.5Minimum insulation thickness19 5.6.6Leak-tightness of casing pipe fittings .19 6Marking .20 6.1General20 6.2Steel service pipe.20 6.3Casing.20 6.4Fitting assembly.20 Annex A (informative) Guidelines for inspection and testing21 Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 04 07:47:49 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 448:2003 (E) 3 A.1Manufacturers type test .21 A.2Manufacturers quality surveillance.21 A.3External inspection21 A.4Extent of inspection.21 A.5Manufacturers responsibility.21 Annex B (informative) Procedures for polyethylene welding24 B.1Introduction24 B.2Requirements for site, machine and equipment 24 B.3Items24 B.4Butt fusion welding .25 B.4.1Equipment 25 B.4.2Welding procedure 26 B.5Extrusion welding26 B.5.1Equipment 26 B.5.2Welding procedure 27 Bibliography28 Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 04 07:47:49 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 448:2003 (E) 4 Foreword This document (EN 448:2003) has been prepared by Technical Committee CEN/TC 107 “Prefabricated district heating pipe systems“, the secretariat of which is held by DS. 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 2003, and conflicting national standards shall be withdrawn at the latest by August 2003. This document supersedes EN 448:1994. Annexes A and B are informative. This document includes a Bibliography. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and the United Kingdom. Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 04 07:47:49 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 448:2003 (E) 5 Introduction The first edition of EN 448 was approved in 1994. The main areas of the revision are: the title has been amended by ”District heating pipes”; the term ”underground” has been changed to ”directly buried”; the mentioning in the foreword of the production method ”injected (poured)” has been deleted; service pipes with nominal diameters from DN 700 up to and including DN 1200 have been added and the requirements have been amended accordingly; casings with nominal outside diameters from 900 mm up to and including 1 400 mm have been added and the requirements have been amended accordingly; the minimum straight length of the casing at the ends of fittings has been changed to 200 mm; the requirements for polyethylene welding have been changed; annex B has been rewritten; the former annex C has been omitted. This specification is part of the standards for bonded systems using polyurethane foam thermal insulation applied to bond to a steel service pipe and a polyethylene casing. For information on the minimum expected thermal life with operation at various temperatures with respect to PUR foam performance see EN 253:2003, annex B. The other standards from TC 107 are: EN 253:2003, District heating pipes Preinsulated bonded pipe systems for directly buried hot water networks Pipe assembly of steel service pipe, polyurethane thermal insulation and outer casing of polyethylene. EN 488:2003, District heating pipes Preinsulated bonded pipe systems for directly buried hot water networks Steel valve assembly for steel service pipes, polyurethane thermal insulation and outer casing of polyethylene. EN 489:2003, District heating pipes Preinsulated bonded pipe systems for directly buried hot water networks Joint assembly for steel service pipes, polyurethane thermal insulation and outer casing of polyethylene. EN 13941:2003, Design and installation of preinsulated bonded pipe systems for district heating. NOTEThe following draft in connection with the above mentioned is under development: prEN 14416, District heating pipes Preinsulated bonded pipe systems for directly buried hot water networks Surveillance systems. Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 04 07:47:49 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 448:2003 (E) 6 1 Scope This European Standard specifies requirements and test methods for fittings of prefabricated thermally insulated pipe-in-pipe assemblies comprising a steel service fitting from DN 20 to DN 1200, rigid polyurethane foam insulation and an outer casing of polyethylene for use in directly buried hot water networks with preinsulated pipe assemblies in accordance with EN 253. This standard covers the following fittings: bends, T-pieces, reducers and anchors. This standard applies only to insulated fitting assemblies for continuous operation with hot water at various temperatures in accordance with clause 1 of EN 253:2003. Guidelines for quality inspection are given in annex A of this standard. Procedures for PE-welding are given in annex B of this standard. NOTEThis standard does not include rules for calculation of loads and stresses. 2 Normative references This European Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text, and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies (including amendments). EN 253:2003, District heating pipes - Preinsulated bonded pipe systems for directly buried hot water networks - Pipe assembly of steel service pipe, polyurethane thermal insulation and outer casing of polyethylene. EN 287-1, Approval testing of welders - Fusion welding Part 1: Steels. EN 288-1:1992, Specification and qualification of welding procedures for metallic materials Part 1: General rules for fusion welding. EN 1418, Welding personnel Approval testing of welding operators for fusion welding and resistance weld setters for fully mechanized and automatic welding of metallic materials. EN 10216-2, Seamless steel tubes for pressure purposes - Technical delivery conditions - Part 2: Non-alloy and alloy steel tubes with specified elevated temperature properties. EN 10217-2, Welded steel tubes for pressure purposes - Technical delivery conditions - Part 2: Electric welded non-alloy and alloy steel tubes with specified elevated temperature properties. EN 10217-5, Welded steel tubes for pressure purposes - Technical delivery conditions - Part 5: Submerged arc welded non-alloy and alloy steel tubes with specified elevated temperature properties. EN 12814-1, Testing of welded joints of thermoplastics semi-finished products Part 1: Bend test. EN 25817:1992, Arc-welded joints in steel - Guidance on quality levels for imperfections (ISO 5817:1992). ISO 1106-3, Recommended practice for radiographic examination of fusion welded joints Part 3: Fusion welded circumferential joints in steel pipes of up to 50 mm wall thickness. ISO 3419:1981, Non-alloy and alloy steel butt welding fittings. ISO 6761, Steel tubes - Preparation of ends of tubes and fittings for welding. Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 04 07:47:49 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 448:2003 (E) 7 3 Terms and definitions For the purposes of this European Standard, the terms and definitions given in EN 253:2003 together with the following apply. 3.1 cold formed bend manufactured by cold bending of steel pipes 3.2 butt welding bend manufactured either by hot bending of steel pipes or by hot forming of steel plates which are subsequently welded together 3.3 bending angle, deviation in direction of the steel pipe centre lines 3.4 forged T-piece manufactured by hot forming of either steel pipes or steel plates which are subsequently welded together 3.5 welding saddle butt welding fitting to be welded into the main pipe for the welded connection between the main pipe and the branch pipe in a T-piece 3.6 welded T-piece manufactured by welding together pieces of steel pipes with or without the use of a welding saddle or a drawn collar on the main pipe Key 3.1 Cold formed bend 3.2 Butt welding bend 3.3 Bending angle, 3.4 Forged T-piece 3.5 T-piece with welding saddle 3.6a T-piece with drawn collar 3.6b Directly welded T-piece Figure 1 Examples Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 04 07:47:49 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 448:2003 (E) 8 3.7 reducer butt welding fitting to be welded between two steel pipes of different diameters 3.8 anchor steel construction used to transfer the axial load from the steel service pipe through the insulation and the casing to a fixed point 4 Requirements 4.1 Steel parts 4.1.1 Quality The material shall be in accordance with 4.2.1 of EN 253:2003. 4.1.2 Wall thickness and diameter The minimum nominal wall thickness of pipes and butt welding fittings shall prior to processing be at least the same as for the straight pip