BS-EN-580 pdf free download

BS-EN-580 pdf free download. Plastics piping systems — Unplasticized poly(vinyl chloride) (PVC-U) pipes — Test methods for the resistance to dichloromethane at a specified temperature (DCMT).
2 Principle A piece of PVC-U pipe, of specified length, chamfered at one end to an angle dependent on its thickness, is immersed for (30 ± 1) min in dichloromethane at a specified temperature to verify that the PVC-U is not attacked at that temperature. The surface area of the dichloromethane is minimized and covered by a thick layer of water on top for safety reasons and to reduce evaporation. After immersion in the dichloromethane, the test piece is left for “dripping off” in the water layer before final drying and inspection. NOTE 1 If the PVC-U has not sufficiently gelled, whitening of the surface will occur and, in the worst case, a precipitate will be observed. NOTE 2 It is assumed that the following test parameters are set by the standard making reference to this standard: a) the control temperature, T , for the dichloromethane (see 4.3 and 6.3); b) the minimum wall thickness for which the test shall be applied. 3 Reagent Dichloromethane, technical grade. NOTE Dichloromethane, technical grade, contains small quantities (1 % maximum each) of chloromethane (CH 3 Cl), of trichloromethane (CHCl 3 ) and of tetrachloromethane (CCl 4 ). It has been noted that even if the level of these impurities were to attain 5 % in total, the results would not be significantly different. WARNING The boiling temperature of dichloromethane is low (40 °C). Consequently, it has a high vapour pressure at ambient temperature. Further, it can be toxic to skin and eyes. It is, therefore, necessary to take precautions when handling dichloromethane or test pieces, which have been immersed in it. The vapours are also toxic: the threshold limit value (T.L.V.) comparable to the maximum admissible concentration (M.A.C.) is 100 ml/m 3 (ppm). Ventilation of the room or the area in which the container is placed and where the drying of the test piece takes place is, therefore, essential. 4 Apparatus 4.1 Chamfering machine (see 5.2) 4.2 Glass or stainless steel container, preferably of suitable dimensions to accommodate one or more test pieces (see clause 5), with a grating maintained at approximately 10 mm above the bottom of the container, a lid to limit evaporation of the liquid (see 6.1 and 6.2) and thermostatic control, with stirrer, capable of maintaining the temperature of the liquid at ( T ± 0,5) °C with help of the refrigeration equipment (4.3) NOTE It is recommended to use a cylindrical container of a suitable small diameter, e.g. slightly greater than 315 mm depending on the dimensions most frequently produced (larger pipes can be cut into a number of longitudinal sections to be able to accommodate to the size of the container, see 5.1). Depending on the local conditions this container may be positioned in an existing vessel, previously used for larger tests, which can be filled with water (see annex B). The temperature control and stirring can take place in the old vessel in case the new container is relatively small and made from a heat transferring material like stainless steel. The grating should be made so it can be positioned in 2 levels as follows: a) with the appropriate part of the test piece or sections of test piece immersed in the dichloromethane; b) with the part of the test piece(s) which were immersed in the dichloromethane fully immersed in the water but not in contact with the dichloromethane. 4.3 Refrigeration equipment, capable of cooling the dichloromethane to the temperature as specified in the referring standard. 4.4 Hood fitted with a fume extraction system, for safety reasons (see warning in clause 3) mounted over the container (4.2). 5 Preparation of the test piece 5.1 Cut from the pipe to be tested a test piece 160 mm in length, such that the cut ends are perpendicular to the axis of the pipe. The wall thickness of the pipe shall be greater than the minimum thickness specified for this test by the referring standard [see item b) of note 2 in clause 2]. BS-EN-580 pdf download.