Pipe for transport of chlorinated water

A pipe for transporting chlorinated water, wherein the pipe is a biaxially oriented pipe made by a process comprising:

• a) forming a polymer composition comprising a polyolefin into a tube, and
• b) stretching the tube of step a) in the axial direction at an axial draw ratio of 1.49 to 3.6 and in the peripheral direction at an average hoop draw ratio of 1.2 to 1.6 to obtain a biaxially oriented pipe;
• wherein the biaxially oriented pipe has a wall thickness of 3.0 to 10.0 mm and improved resistance to chlorinated water compared to the same pipe that has not been biaxially oriented, wherein:
• the improved resistance is resistance to crack formation on the inner surface of the pipe;
• the chlorinated water is water dosed with chlorine, chlorine dioxide and/or chloramines;
• the total amount of chlorine, chlorine dioxide and chloramines is 0.01 to 4.0 ppm by weight with respect to the chlorinated water;
• and
• the amount of chlorine dioxide is 0.01 to 4.0 ppm by weight with respect to the chlorinated water;
• and
• wherein the polymer composition comprises pipe grade PE100 high density polyethylene (HDPE) having:
• a minimum required strength (MRS) of 10 MPa, measured according to ISO 12162:2009 (E);
• a bimodal or multimodal molecular weight distribution;
• a density of 940 to 960 kg/m3, measured according to ISO1183;
• and
• a Melt Flow Rate of 0.1 to 1 g/10 min measured according to ISO1133-1:2011 (190° C./5 kg).