EN 448:2015

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.RG]HPHOMVNDFernwärmerohre - Werkmäßig gedämmte Verbundmantelrohrsysteme für direkt erdverlegte Fernwärmenetze - Verbundformstücke, bestehend aus Stahl-Mediumrohr, Polyurethan-Wärmedämmung und Außenmantel aus PolyethylenTuyaux de chauffage urbain - Systèmes bloqués de tuyaux préisolés pour les réseaux enterrés d'eau chaude - Raccords préisolés, tubes de service en acier, isolation thermique en polyuréthanne et tube de protection en polyéthylèneDistrict 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 polyethylene91.140.65Oprema za ogrevanje vodeWater heating equipment23.040.40Kovinski fitingiMetal fittings23.040.07Cevovodi za daljinsko ogrevanje in njihovi deliPipeline and its parts for district heatICS:Ta slovenski standard je istoveten z:EN 448:2015SIST EN 448:2016en,fr,de01-januar-2016SIST EN 448:2016SLOVENSKI
STANDARDSIST EN 448:20091DGRPHãþD

EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 448
November 2015 ICS 23.040.40 Supersedes EN 448:2009English 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 préisolés pour des réseaux d'eau chaude enterrés directement - Raccords préisolés pour tubes de service en acier, isolation thermique en polyuréthane et tube de protection en polyéthylène
Fernwärmerohre - Werkmäßig gedämmte Verbundmantelrohrsysteme für direkt erdverlegte Fernwärmenetze - Verbundformstücke, bestehend aus Stahl-Mediumrohr, Polyurethan-Wärmedämmung und Außenmantel aus Polyethylen This European Standard was approved by CEN on 5 September 2015.
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 CEN-CENELEC 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 CEN-CENELEC Management Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre:
Avenue Marnix 17,
B-1000 Brussels © 2015 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 448:2015 ESIST EN 448:2016

Guidelines for inspection and testing . 23 A.1 General . 23 A.2 Manufacturer’s type test . 23 A.3 Manufacturer’s quality control . 23 A.4 External inspection . 23 A.5 Extent of inspection . 23 A.6 Manufacturer’s responsibility . 23 Annex B (informative)
Procedures for polyethylene welding . 26 B.1 General . 26 B.2 Recommendations for site, machine and equipment . 26 B.3 Items . 26 B.4 Butt fusion welding . 26 B.5 Extrusion welding . 28 Bibliography . 30
deviation in direction of the steel pipe centre lines 3.3 butt welded bend bend manufactured either by hot bending of steel pipe or by hot forming of steel plates which are subsequently welded together 3.4 cold formed bend bend manufactured by cold bending of steel pipe 3.5 cap not pre-insulated butt welded fitting to be welded on the end of a pipe or fitting 3.6 fitting reducer, tee, factory-made elbow and bend, cap, welding stub, mechanical joint 3.7 forged T-piece T-piece manufactured by hot forming of either steel pipes or steel plates which are subsequently welded together 3.8 hot formed bend bend manufactured by heating pipe during bending 3.9 induction bend bend manufactured by induction bending 3.10 induction bending continuous bending process which utilizes induction heating to create a narrow, circumferential, heated band around the material being bent 3.11 nominal size, DN alphanumeric designation of size, common to components in piping systems which are used for reference purposes [SOURCE: EN ISO 6708:1995, 2.1, modified] SIST EN 448:2016

Key a cold or hot formed bends e tee with welding saddle b butt welding bend or elbows f tee with drawn collar c
g directly welded tee d forged tee
Figure 1 — Examples SIST EN 448:2016

For Sweden, a deviating situation is applicable for EN 253:2009+A2:2015, Table 1 (see the A-deviation in EN 253:2009+A2:2015, Annex G). 4.1.3 Wall thickness and diameter According to the scope of this European Standard, all components shall be designed for a minimum of 16 bar. NOTE If the fitting assemblies have to be used in situations with pressures higher than 16 bar, extra calculations will be necessary. The minimum nominal wall thickness of all components shall prior to processing be at least the same as for the straight pipes. The nominal diameter, the outside diameter and the minimum nominal wall thickness shall be the same as for the straight pipes in accordance with EN 253:2009+A2:2015, Table 2. The tolerances on the outside diameter of the pipe ends shall be in accordance with EN 253:2009+A2:2015, Table 3. Subject to design considerations other wall thicknesses than those given in EN 253:2009+A2:2015, Table 2 may be used, but in no case shall these be less than the minima indicated in EN 253:2009+A2:2015, Table 2. All components shall be designed in accordance with EN 13941, for the actions and stresses that normally occur during a system's entire service life. 4.1.4 Bends 4.1.4.1 Butt welding bends The dimensions shall be in accordance with EN 10253-2 with the exception that the bend radius shall be
· 1,5 times the outer diameter. 4.1.4.2 Cold formed bends Cold formed bends shall be produced from seamless pipe or longitudinal welded pipes. At cold formed bends made of longitudinal welded pipes the weld bead shall be welded to factor V = 1 (calculation stress = 100 %). After bending, the minimum wall thickness of the bent pipe shall be not less than 85 % of the nominal wall thickness of the straight pipe (see EN 253:2009+A2:2015, Table 2). The maximum ovality in the bent area shall not exceed 6 %. The formula for the calculation of the ovality is: ()sDDD−=×os maxs min 100 (1) where SIST EN 448:2016

¶ DN 200 ±2,0° > DN 200 ±1,0° 4.1.5 T-pieces 4.1.5.1 Forged T-pieces The wall thickness T and T1, see EN 10253-2, shall be at least the same as those for the straight pipes, see EN 253:2009+A2:2015, Table 2. All other dimensions shall be in accordance with EN 10253-2. 4.1.5.2 Welding saddles Welding saddles shall be of the type which shall be welded into the wall of the main pipe. The wall thickness of the welding saddles shall be at least the same as the wall thicknesses of the main pipes and the branch pipes which shall be welded to the saddles. 4.1.5.3 Welded T-pieces Welded T-pieces shall be manufactured either by using welding saddles or by drawing a collar on which the branch pipe is welded or by welding the branch pipe directly to the main pipe. The wall thickness of the collar shall be at least the same as that for the branch pipe, see EN 253:2009+A2:2015, Table 2. The collar shall be drawn opposite the welding seam in the main pipe. When using branch pipe directly welded to the main pipe, compensating (reinforcement) plates can be used according to EN 13941 requirements. SIST EN 448:2016
...