Abstract:
In the paper work are highlighted the current technical regulations on the use of PVC pipes, with small diameters, for channeling domestic waste water from the populated hearth centers. In the case of small or very small debits leakage, are recommended tubes with minimum limits allowed for diameters and maximum limits allowed for degrees of filling, to avoid, clogged drain sections with the most toxic or combustible gases resulting by anaerobic fermentation of the organic masses from drainage waters.These phenomena can occur when changing pipes DN 250 mm of concrete, more rugged, with PVC-KG, smoother, even with DN 200 mm and DN 150 mm.These substitutions are allowed for economic reasons and by the fact that the transport flows is equivalent.Reducing the diameter drain pipes, even for equivalent flow rates, causes high degrees of filling, over the allowed limit of 0.6 for pipes with diameters less than 250 mm. By reducing the diameters under minimum allowed limits is possible only if the filling degrees do not excess the maximum allowable levels
