A composition is provided which comprises a propylene ethylene random copolymer having a melt flow rate (MFR) (as determined according to ASTM D1238, 230° C., 2.16 Kg) of less than 1 g/10 min, a xylene solubles content of less than 7% by weight, an ethylene content of from 3 to 5 percent by weight of the copolymer, and a value equal to or greater than 92 for the product of the Koenig B value times the % mm triads measured on the xylene insoluble fraction of the random copolymer obtained by the wet method. Pipes made from the composition demonstrate improved pressure endurance.