EN 253:2009

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.RG]HPHOMVNDFernwärmerohre - Werkmäßig gedämmte Verbundmantelrohrsysteme für direkt erdverlegte Fernwärmenetze - Verbund-Rohrsystem bestehend aus Stahl-Mediumrohr, Polyurethan-Wärmedämmung und Außenmantel aus PolyethylenTuyaux de chauffage urbain - Systèmes bloqués de tuyaux préisolés pour les réseaux d'eau chaude enterrés directement - Tube de service en acier, isolation thermique en polyuréthane et tube de protection en polyéthylèneDistrict 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 polyethylene91.140.65Oprema za ogrevanje vodeWater heating equipment23.040.10Železne in jeklene ceviIron and steel pipesICS:Ta slovenski standard je istoveten z:EN 253:2009SIST EN 253:2009en,fr01-april-2009SIST EN 253:2009SLOVENSKI
STANDARDSIST EN 253:2004/A2:2007SIST EN 253:2004/A1:2006SIST EN 253:20041DGRPHãþD

EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 253January 2009ICS 23.040.10Supersedes EN 253:2003
English VersionDistrict heating pipes - Preinsulated bonded pipe systems fordirectly buried hot water networks - Pipe assembly of steelservice pipe, polyurethane thermal insulation and outer casing ofpolyethyleneTuyaux de chauffage urbain - Systèmes bloqués de tuyauxpréisolés pour les réseaux d'eau chaude enterrésdirectement - Tube de service en acier, isolation thermiqueen polyuréthane et tube de protection en polyéthylèneFernwärmerohre - Werkmäßig gedämmteVerbundmantelrohrsysteme für direkt erdverlegteFernwärmenetze - Verbund-Rohrsystem bestehend ausStahl-Mediumrohr, Polyurethan-Wärmedämmung undAußenmantel aus PolyethylenThis European Standard was approved by CEN on 5 December 2008.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 obtained on application to the CEN 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 translationunder the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, 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.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2009 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 253:2009: ESIST EN 253:2009

Relation between actual continuous operating conditions and accelerated ageing test conditions . 31Annex B (informative)
Calculation of the minimum expected thermal life with operation at various temperatures with respect to PUR foam performance . 33Annex C (normative)
Calculated continuous operating temperature (CCOT) . 34C.1General. 34C.2Symbols . 34C.3Ageing and shear strength determinations . 34C.4Calculations . 35C.4.1Determination of the thermal life at different ageing temperatures . 35C.4.2Adoption to the Arrhenius relation . 35C.4.3Calculated continuous operating temperature, CCOT . 35Annex D (informative)
Guidelines for inspection and testing . 37D.1General. 37D.2Manufacturer's type test . 37D.3Manufacturer’s quality control . 37D.4External inspection . 37D.5Manufacturer's responsibility . 37Annex E (informative)
Radial creep behaviour of the polyurethane foam (PUR) . 40Annex F (normative)
Thermal conductivity of pre-insulated pipes - Test procedure . 41F.1Scope . 41F.2Requirements (EN ISO 8497:1996, Clause 5) . 41F.2.1Test specimen (EN ISO 8497:1996, 5.1) . 41F.2.2Operating temperature (EN ISO 8497:1996, 5.2) . 41F.2.3Types of apparatus (EN ISO 8497:1996, 5.5) . 41F.3Apparatus (EN ISO 8497:1996, Clause 7) . 41F.3.1Guarded end apparatus . 41F.3.2Calibrated end apparatus. 41F.3.3Dimensions (EN ISO 8497:1996, 7.2) . 42F.3.4Heater pipe surface temperature . 42F.4Test specimens (EN ISO 8497:1996, Clause 8) . 42F.4.1Conditioning (EN ISO 8497:1996, 8.4) . 42F.4.2Dimension measurement (EN ISO 8497:1996, 8.5) . 42F.4.3Surface temperature measurement . 42F.5Procedure (EN ISO 8497:1996, Clause 9) . 42F.5.1Test length (EN ISO 8497:1996, 9.1.1) . 42F.5.2Diameter (EN ISO 8497:1996, 8.5) . 42F.5.3Thickness of casing . 43F.5.4Ambient requirements (EN ISO 8497:1996, 9.2) . 43F.5.5Test pipe temperature (EN ISO 8497:1996, 9.3) . 43F.5.6Power supply (EN ISO 8497:1996, 7.9) . 43F.5.7Axial heat loss (EN ISO 8497:1996, 5.7) . 43F.5.8Test period and stability (EN ISO 8497:1996, 9.5.3) . 43F.6Calculations (EN ISO 8497:1996, Clause 11) . 43F.6.1Thermal conductivity (EN ISO 8497:1996, 3.5) . 43F.7Symbols and units (EN ISO 8497:1996 Clause 4) . 44Annex G (informative)
National A-deviations . 46G.1Swedish national legislative deviations on steel service pipes . 46Annex H (informative)
Main changes from the previous edition of EN 253 . 47Annex I (informative)
Waste treatment and recycling . 49Bibliography . 50SIST EN 253:2009

Outside diameter Ds mm Minimum nominal wall thickness T mm 15 20 25 21,3 26,9 33,7 2,0 2,0 2,3 32 40 50 42,4 48,3 60,3 2,6 2,6 2,9 65 80 100 76,1 88,9 114,3 2,9 3,2 3,6 125 150 200 139,7 168,3 219,1 3,6 4,0 4,5 250 300 350 273,0 323,9 355,6 5,0 5,6 5,6 400 450 500 406,4 457,0 508,0 6,3 6,3 6,3 600 700 800 610,0 711,0 813,0 7,1 8,0 8,8 900 1 000 1 200 914,0 1 016,0 1 219,0 10,0 11,0 12,5
Table 3 — Tolerances on outside diameter Ds at pipe ends Welded pipe
Seamless pipe Ds mm Tolerance mm Ds mm Tolerance mm Ds ≤ 48,3 ±0,3 Ds ≤ 114,3 ±0,4 48,3 < Ds ≤ 168,3 ±0,005 Ds
114,3 < Ds ≤ 219,1 ±0,005 Ds
168,3 < Ds ≤ 323,9 ±1,0 219,1 < Ds ≤ 711,0 ±0,006 Ds
323,9 < Ds ≤ 1219,0 ±1,6
Seamless pipe T mm ±∆T mm T mm +∆T mm -∆T mm 2,0 0,3 2,0 0,3 0,2 2,3 0,3 2,3 0,4 0,2 2,6 0,3 2,6 0,4 0,3 2,9 0,3 2,9 0,4 0,3 3,2 0,3 3,2 0,4 0,4 3,6 0,4 3,6 0,5 0,5 4,0 0,5 4,0 0,5 0,5 4,5 0,5 4,5 0,6 0,6 5,0 0,5 5,0 1,0 0,6 5,6 0,5 5,6 1,1 0,7 6,3 0,5 6,3 1,3 0,9 7,1 0,5 7,1 1,4 1,1 8,0 0,5 8,0 1,4 1,1 8,8 0,5 8,8 1,4 1,1 10,0 0,5 10,0 1,4 1,1 11,0 0,5 11,0 1,4 1,1 12,5 0,5 12,5 1,4 1,1
4.2.4 Surface condition In order to ensure proper bonding between the steel service pipe and the PUR-foam insulation, the following procedure shall be followed: Prior to insulation, the outer surface of the pipe shall be cleaned so that it is free from rust, mill scale, oil, grease, dust, paint, moisture and other contaminants. Before cleaning the pipe, the outer surface of the pipe shall comply with rust grade A, B or C according to EN ISO 8501-1:2007, without pitting. 4.3 Casing 4.3.1 Material properties 4.3.1.1 Material composition The casing may be a separately manufactured pipe or be applied directly onto the insulation by extrusion. The pipe material shall be black coloured PE virgin or rework material containing only those anti-oxidants, UV-stabilizers and carbon black necessary for the manufacture and end use of pipes to this specification. The black coloured PE material to be extruded shall be tested in accordance with EN ISO 9080 and classified at least a PE 80 material in accordance with EN ISO 12162. The carbon black content shall, when tested in accordance with ISO 6964, be (2,5 ± 0,5) % by mass.
emin mm 75 90 110 3.0 3,0 3,0 125 140 160 3,0 3,0 3,0 180 200 225 3,0 3,2 3,4 250 280 315 3,6 3,9 4,1 355 400 450 4,5 4,8 5,2 500 560 630 5,6 6,0 6,6 710 800 900 7,2 7,9 8,7 1 000 1 100 1 200 1 400 9,4 10,2 11,0 12,5
4.3.2.3 Appearance, surface finish, pipe ends The internal and external surfaces1) of the casing pipe shall be clean and free from such grooving or other defects that might impair its functional properties (see 5.2.1). The pipe ends shall be cleanly cut and shall be square within 2,5° with the axis of the pipe. 4.3.2.4 Elongation at break The elongation at break determined in accordance with 5.2.2 shall not be less than 350 %. The test is to be applied only on casings that are produced partly or fully from rework material.
1) Surface treatment to improve the shear strength between the PUR foam and casing pipe is permissible provided that the treated pipe still complies with the specification. SIST EN 253:2009

4.4.3 Compressive strength The compressive strength or the compressive stress at 10 % relative deformation as defined in ISO 844 shall be not less than 0,3 MPa in a radial direction when tested in accordance with 5.3.3. 4.5 Pipe assembly 4.5.1 General All requirements are valid including the diffusion barrier, if any. 4.5.2 Pipe ends Both ends of the service pipe shall be free from insulation for a minimum of 150 mm. The tolerance on the declared value shall be ± 10 mm. Service pipe ends shall be prepared for welding in accordance with EN ISO 9692-1. 4.5.3 Diameter and wall thickness of the casing The outside diameter of the PE casing shall at any point be between the minimum diameter Dmin and the maximum diameter Dmax as given in Table 6. The minimum wall thickness of the PE casing, emin, shall at any point be in accordance with Table 6. The measured values for the outside diameter and wall thickness shall be rounded off to the next higher 0,1 mm. SIST EN 253:2009

4.5.4 Centre line deviation The distance between the centre lines of the service pipe and the casing at any point shall not exceed the limits given in Table 7. Table 7 — Centre line deviation related to the nominal diameters Nominal outside diameter of PE pipe mm Maximum centre line deviation mm
75 to 160 180 to 400 450
to 630 710 to 800 900 to 1400 3,0 5,0 8,0 10,0 14,0
min. MPa Test clause ττττtan
min. MPa 23 ± 2 5.4.1.4 0,12 5.4.2 0,20 140 ± 2 5.4.1.5 0,08 — —
4.5.6 Thermal conductivity in unaged condition When tested in accordance with 5.4.4, the thermal conductivity (λ50) shall not exceed 0,029 W/(m × K). For type test the thermal conductivity shall be reported together with the foam density, cell size and composition of the gas in the cells of the insulation. 4.5.7 Thermal conductivity at artificially aged condition When aged according to 5.4.5 the test shall be performed in accordance with 5.4.4. For type test the thermal conductivity shall be reported together with the foam density, cell size and composition of the gas in the cells of the insulation. 4.5.8 Impact resistance After testing in accordance with 5.4.6, the casing shall have no visible cracks. 4.5.9 Long term creep resistance and modulus The long term creep resistance value obtained by the test method in 5.4.7 shall be documented by the manufacturer. SIST EN 253:2009
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