【正文】 and 180176。 the impact energy shall be adjusted to within 5 %. Care shall be taken to ensure that the impact energy is maintained at a constant level by ensuring that little or no friction is encountered when the falling weight is dropped. The test shall be carried out at an ambient temperature of (20 ? 5) 176。C ). Immediately after removal from the tank and simple wiping off their surface with a dry cloth, the specimens shall be weighed again and their weight increase calculated. Subsequently the absorbed solution shall be evaporated in accordance with ISO 62 Method 2。 the samples shall be reweighed and their weight decrease calculated. Immersion test in diluted sulphuric acid The immersion test in diluted sulphuric acid shall be performed on a detached specimen of polyurethane lining, approximately 1 mm in thickness, produced and cured in a similar way to the pipe lining. The dry specimens shall be weighed, then immersed for 100 days in 10 % volume diluted sulphuric acid at 50 176。C (+/ 2 176。C directly on the pipe barrel for each DN group. The mean value of 6 measurements per pipe is indicated whereby no values under 8 MPa are acceptable. If one value under 8 MPa is obtained, then a new set of measurements shall be repeated at the same location of the pipe after it has been rotated by approximately 60176。C and 30 176。C. Abrasion resistance (only for waste water application) When tested in accordance with , the pipes shall not have an abrasion depth greater than 0,2 mm after 100 000 movements. NOTE In order to test the abrasion resistance of fittings, straight fittings as flanged pipes, etc. may be lined as fittings and tested according to . Light ageing After 6 months storage outside exposed to atmospheric conditions, the lining shall show no damage when tested according to . 11 BS EN 15655:2020 EN 15655:2020 (E) Materials in contact with water intended for human consumption When used under the conditions for which they are designed, in permanent or in temporary contact with water intended for human consumption, the polyurethane lining applied on ductile iron pipes and fittings shall not change the quality of that water to such an extent that it fails to ply with the requirements of national regulations. For this purpose, reference shall be made to the relevant national regulations and standards, transposing EN standards when available, dealing with the influence of materials on water quality and to the requirements for external systems and ponents as given in EN 805. NOTE A European Acceptance Scheme (EAS) is in course of development in relation to the Construction Products Directive and to the Drinking Water Directive。C Mass change after subsequent drying % % Immersion test ISO 62, method 2 Less than 15 % weight increase Less than 2 % weight loss Mass change after 100 days in sulphuric acid 10 % at 50 176。C to 30 176。 ? multilayer of epoxy, PUREpoxy. When spigot end and socket entrance are coated with epoxy or polyurethane, the manufacturer shall ensure that the joint can be assembled. The coating thickness shall be checked according to . Repairs In case of holidays or damage, repairs shall be carried out in accordance with the manufacturer’s written instructions. Repairs shall be checked according to . Fresh surfaces of pipes cut on site shall be protected by appropriate coatings according to the manufacturer39。 ? polyurethane in accordance with this standard with a minimum lining thickness of 150 ?m。 ? uniform appearance and smoothness except for admissible repairs。 or ? 10 pieces of ductile cast iron fittings DN 300 according to EN 598, internal PURlining according to EN 15655. 5 Technical Requirements Surface preparation Prior to application of the polyurethane lining, the surface of the pipes or fittings to be lined shall be clean, free of rust, loose constituent materials, dirt, oil, grease and moisture. In cold weather, or anytime when the moisture tends to condense on the surface of the pipe or fitting, it shall be uniformly warmed for sufficient time to dry prior to cleaning. The surface temperature shall be maintained at least 5 176。C. 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 (including any amendments) applies. EN 545, Ductile iron pipes, fittings, accessories and their joints for water pipelines — Requirements and test methods EN 598:2020, Ductile iron pipes, fittings, accessories and their joints for sewerage applications — Requirements and test methods EN 969, Ductile iron pipes, fittings, accessories and their joints for gas pipelines — Requirements and test methods EN ISO 4624, Paints and varnishes — Pulloff test for adhesion (ISO 4624:2020) ISO 62:2020, Plastics — Determination of water absorption ISO 527–3:1995, Plastics — Determination of tensile properties – Part 3: Test conditions for films and sheets ISO 868, Plastics and ebonite — Determination of indentation hardness by means of a durometer (Shore hardness) ISO 8501–1:2020, Representative photographic examples of the change of appearance imparted to steel when blastcleaned with different abrasives ISO 8503–1:1988, Preparation of steel substrates before application of paints and related products — Surface roughness characteristics of blastcleaned steel substrates — Part 1: Specifications and definitions for ISO surface profile parators for the assessment of abrasive blastcleaned surfaces 3 Terms and definitions For the purposes of this document, the foll