Testing of Dacta Therm PP-R pipes and fittings Testing of Dacta Therm PP-R pipes and fittings a. Density Test: According to ISO 1183 standard, the density is determined by weighing the material. This value is 0.9 g/cm3 for PP-R material. b. Melt Flow Index (MFI): a measure of the ease of flow of the melt of a thermoplastic polymer. It is defined as the mass of polymer, in grams, flowing in ten minutes through a capillary of a specific diameter and length by a pressure applied via prescribed alternative gravimetric weights for alternative prescribed temperatures. The method is described in ISO 1133. The average value for PP-R is upto 0.50 gr/10 min. c. Charpy Impact Test: also known as the Charpy V-notch test, is a standardized high strainrate test which deter- mines the amount of energy absorbed by a material during fracture. This absorbed energy is a measure of a given material’s notch toughness and acts as a tool to study temperature- dependent ductile-brittle transition. ISO 9854 specifies a method for determining the Charpy impact strength of the product. d. Longitudinal Reversion: This test is standardized in EN ISO 2505, which specifies a method for determin- ing the longitudinal reversion of thermoplastics pipes, to be carried out in either a liquid or in air. The pipe is left in the oven for a certain period of time and then removed. The height and diameter variation is calculated after cooling. According to the standards EN 15874 and DIN 8078, this value must not be greater than 3% in length and 2% in diameter.
e. Pressure Test: The internal pressure test is standardized in ISO 1167. “Thermoplastic pipes for the conveyance of fluids - Resistance to internal pres- sure - Test method”. The test specifies a method for determination of the resistance to constant internal pressure at constant temperature. Hydrostatic internal pressure tests are carried out in different pressure values at 20 °C 95 °C for 22 hours, 165 hours and 1000 hours intervals. During this time, the pipes should not burst. In addition to raw materials used in the pressure specified in the standard temperature of 110 °C 8760 hours (one year) are tested. This test can guarantee the material life of 50 years. f. Homogeneity Test: This test is standardized in EN ISO 13949 which is the method for the assessment of the degree of pigment dispersion in polyolefin pipes, fittings and compounds. The pipe cross-section taken from the surface microns is examined under the microscope to determine whether or not structural deterioration or gaps of non-homogeneous structure exist.
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