BS-EN-253-1995.pdf

BRITISH STANDARD BS EN 253:1995 Preinsulated bonded pipe systems for underground hot water networks Pipe assembly of steel service pipes, polyurethane thermal insulation and outer casing of polyethylene The European Standard EN 253:1994 has the status of a British Standard Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 01 05:23:40 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN 253:1995 This British Standard, having been prepared under the direction of the Refrigeration, Heating and Air Conditioning Standards Policy Committee, was published under the authority of the Standards Board and comes into effect on 15 March 1995 © BSI 09-1999 The following BSI references relate to the work on this standard: Committee reference RHE/9 Draft for comment 93/709555 DC ISBN 0 580 23367 7 Cooperating organizations The European Committee for Standardization (CEN), under whose supervision this European Standard was prepared, comprises the national standards organizations of the following countries: AustriaOesterreichisches Normungsinstitut BelgiumInstitut belge de normalisation DenmarkDansk Standard FinlandSuomen Standardisoimisliito, r.y. FranceAssociation française de normalisation GermanyDeutsches Institut für Normung e.V. GreeceHellenic Organization for Standardization IcelandTechnological Institute of Iceland IrelandNational Standards Authority of Ireland ItalyEnte Nazionale Italiano di Unificazione LuxembourgInspection du Travail et des Mines NetherlandsNederlands Normalisatie-instituut NorwayNorges Standardiseringsforbund PortugalInstituto Portuguès da Qualidade SpainAsociación Española de Normalización y Certificación SwedenStandardiseringskommissionen i Sverige SwitzerlandAssociation suisse de normalisation United KingdomBritish Standards Institution Amendments issued since publication Amd. No.DateComments Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 01 05:23:40 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN 253:1995 © BSI 09-1999i Contents Page Cooperating organizationsInside front cover National forewordii Foreword2 Text of EN 2535 National annex NA (informative) Committees responsible22 National annex NB (informative) Cross-referencesInside back cover Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 01 05:23:40 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN 253:1995 ii © BSI 09-1999 National foreword This British Standard has been prepared under the direction of the Refrigeration, Heating and Air Conditioning Standards Policy Committee and is the English language version of EN 253:1994 Preinsulated bonded pipe systems for underground hot water networks Pipe assembly of steel service pipes, polyurethane thermal insulation and outer casing of polyethylene, published by the European Committee for Standardization (CEN). This standard supersedes BS EN 253:1991, which is withdrawn. EN 253 was produced as a result of international discussion in which the UK took an active part. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, the EN title page, pages 2 to 22, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 01 05:23:40 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM EN 253 October 1994 ICS 23.040.90Supersedes EN 253:1990 Descriptors: Water pipelines, buried pipes, hot water, steel tubes, thermal insulation, polyurethane, polyethylene, specifications, tests, marking English version Preinsulated bonded pipe systems for underground hot water networks Pipe assembly of steel service pipes, polyurethane thermal insulation and outer casing of polyethylene Systèmes bloqués de tuyaux préisolés pour les réseaux enterrés deau chaude Tuyau préisolé Tube de service en acier Isolation thermique en polyuréthane et protection en polyéthylène Werkmäßig gedämmte Verbundmantelrohrsysteme für erdverlegte Fernwärmenetze Verbund-Rohrsystem bestehend aus Stahl-Mediumrohr, Polyurethan-Wärmedämmung und Außenmantel aus Polyethylen This European Standard was approved by CEN on 1994-10-14. 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 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 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, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comité Européen de Normalisation Europäisches Komitee für Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels © 1994 Copyright reserved to CEN members Ref. No. EN 253:1994 E Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 01 05:23:40 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 253:1994 © BSI 09-1999 2 Foreword This European Standard supersedes EN 253:1990 and was drawn up by the Technical Committee CEN/TC 107, Prefabricated district heating pipe systems, the secretariat of which is held by the Danish Standards Association. 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 April 1995, and conflicting national standards shall be withdrawn at the latest by April 1995. The main areas of the revision are: 1. The requirements for the PE quality have been updated. 2. Any reference to CFC has been deleted and alternative blowing agents have been taken into consideration. This specification is part of the standards for bonded systems using polyurethane foam thermal insulation applied by injecting (pouring), to bond to a steel service pipe and a polyethylene casing pipe. The other standards from TC 107 are: EN 448:1994 Fittings EN 488:1994 Valves EN 489:1994 Joints In compiling this document TC 107 has made use of results of research carried out by system manufacturers, raw material suppliers, users, universities and research institutes. In accordance with the CEN/CENELEC Common Rules, the following CEN members are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. Contents Page Foreword2 1Scope5 2Normative references5 3Definitions6 4Requirements6 4.1Steel service pipe6 4.1.1Quality7 4.1.2Diameter7 4.1.3Wall thickness7 4.1.4Surface condition7 4.2Casing pipe7 4.2.1Material properties7 4.2.2Casing properties8 4.3Polyurethane rigid foam insulation (PUR)8 4.3.1Composition8 4.3.2Cell structure8 4.3.3Density9 4.3.4Compressive strength9 4.3.5Water absorption at elevated temperature9 4.4Pipe assembly9 4.4.1Pipe ends9 4.4.2Increase in diameter of the casing pipe9 4.4.3Centre line deviation9 4.4.4Expected life and long-term temperature resistance9 4.4.5Thermal conductivity in unaged condition9 4.4.6Impact resistance9 4.4.7Creep resistance9 5Test methods9 5.1General9 5.1.1Test specimens9 5.2Casing pipe10 5.2.1Material density10 5.2.2Dimensions10 5.2.3Appearance and surface finish10 5.2.4Heat reversion10 5.2.5Long-term mechanical properties10 5.2.6Long-term mechanical properties, casing pipes10 5.2.7Elongation at break10 5.3Polyurethane rigid foam (PUR)11 Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 01 05:23:40 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 253:1994 © BSI 09-19993 Page 5.3.1Composition11 5.3.2Cell structure11 5.3.3Density11 5.3.4Compressive strength12 5.3.5Water absorption12 5.4Pipe assembly12 5.4.1Increase in diameter of the casing pipe12 5.4.2Axial shear strength12 5.4.3Tangential shear strength12 5.4.4Shear strength of the pipe assembly after ageing13 5.4.5Thermal conductivity13 5.4.6Impact resistance13 5.4.7Creep resistance13 6Marking13 6.1Polyethylene pipe13 6.2Pipe assembly13 Annex A (informative) Relation between actual continuous operating conditions and accelerated ageing test conditions16 Annex B (informative) Calculation of the minimum expected life with operation at various temperatures with respect to PUR foam performance16 Annex C (informative) Guidelines for inspection16 Annex D (informative) Change of blowing agent and influence on thermochemical and thermomechanical properties of polyurethane rigid foam (PUR)20 Annex E (informative) National A-deviations21 Figure 1 Tensile test bars11 Figure 2 Axial shear test arrangement14 Figure 3 Tangential shear test arrangement15 Figure A.1 Relationship between the expected life L at a continuous operating temperature Ú for the minimum requirements outlined in 4.4.4.1 and the accelerated ageing test periods and temperatures outlined in 5.4.417 Table 1 Steel service pipe dimensions7 Table 2 Long-term mechanical properties7 Table 3 Casing pipe dimensions8 Table 48 Table 5 Centre line deviation related to the nominal diameters9 Page Table 6 Shear strength9 Table 7 Number of test bars related to the nominal diameters10 Table C.1 Service pipe inspection18 Table C.2 Polyethylene-casing inspection18 Table C.3 Polyurethane foam insulation (PUR) inspection19 Table C.4 Pipe assembly inspection20 Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 01 05:23:40 GMT+00:00 2006, Uncontrolled Copy, (c) BSI 4 blank Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 01 05:23:40 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 253:1994 © BSI 09-19995 1 Scope This European Standard specifies requirements and test methods for straight lengths of prefabricated thermally insulated pipe-in-pipe assemblies for underground hot water networks, comprising a steel service pipe from DN 20 to DN 600, rigid polyurethane foam insulation and an outer casing of polyethylene. However, the quality requirements can be applied for larger dimensions. This standard applies only to injected (poured) insulated pipe assemblies, for continuous operation with hot water at various temperatures up to 120 °C and occasionally with a peak temperature up to 140 °C. The estimation of expected life with continuous operation at various temperatures is outlined in Annex B. 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 the undated references, the latest edition of the publication referred to applies. ISO 844:1978, Cellular plastics Compression test of rigid materials. ISO 845:1988, Cellular plastics and rubbers Determination of apparent (bulk) density. ISO 1133:1991, Plastics Determination of the melt flow rate of thermoplastics. ISO 1167:1973, Plastics pipes for the transport of fluids Determination of the resistance to internal pressure. ISO 1183:1987, Plastics Methods for determining the density and relative density of non-cellular plastics. ISO 2506:1981, Polyethylene pipes (PE) Longitudinal reversion Test methods and specification. ISO 3126:1974, Plastics pipes Measurement of dimensions. ISO 3127:1980, Unplasticized polyvinyl chloride (PVC) pipes for the transport of fluids. Determination and specification of resistance to external blows. ISO 4200:1985, Plain end steel tubes, welded end seamless General tables of dimensions and masses per unit length. ISO 4590:1981, Cellular plastics Determination of volume percentage of open and closed cells of rigid materials. ISO 6761:1981, Steel tubes preparation of ends of tubes and fittings for welding. ISO 8501-1:1988, Preparation of steel substrates before application of paints and related products Visual assessment of surface cleanliness Part 1: Rust grades and preparation grades of uncoated steel substrates and of steel substrates after overall removal of previous coatings. ISO 9329-1:1989, Seamless steel tubes for pressure purposes Technical delivery conditions Part 1: Unalloyed steels with specified room temperature properties1). ISO 9330-1:1990, Welded steel tubes for pressure purposes Technical delivery conditions Part 1: Unalloyed steel tubes with specified room temperature properties1). ISO/TR 10837:1991, Determination of the thermal stability of polyethylene (PE) for use in gas pipes fittings. ISO/CD 1872-2, Plastics Polyethylene (PE) thermoplastics Part 2: Preparation of test specimens and determination of properties Revision of ISO 1872-2:1989. ISO/DIS 3607, Polyethylene (PE) pipes Tolerances on outside diameters and wall thickness Revision of ISO 3607:1977. ISO/DIS 8497, Thermal insulation Determination of steady-state thermal transmission properties Pipe insulation apparatus2). 1) Equivalent national standards may be used. 2) ISO/DIS 8497 has been submitted for voting (April 1988). Until ISO 8497 is published, any equivalent national standard can be used. Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 01 05:23:40 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 253:1994 6 © BSI 09-1999 3 Definitions For the purposes of this standard the following definitions apply. 3.1 ageing carried out by keeping the service pipe at a certain, elevated temperature for a certain time while the casing pipe is exposed to room temperature 3.2 bonded system a system consisting of a service pipe, insulating material and a casing pipe which are bonded by the insulating material 3.3 casing pipe a pipe protecting the insulation and the service pipe from ground water, moisture and mechanical damage 3.4 continuous temperature the temperature at which the hot water network is designed to operate continuously 3.5 core density the apparent density of the foam in the central part of the insulating layer 3.6 density the mass of a body of a material divided by the volume of the body 3.7 density of PE-raw material is determined in accordance with ISO 1183 method A or D on the extruded material from the melt flow rate measure