Cold water at a flow rate of 2000 kg/h and a temperature of 40°C will be heated to 75°C by using hot water at a temperature of 93.2°C and a flow of 1500 kg/h. For this purpose, a double-pipe heat exchanger with 1 in Sch 40 inside and 2 in Sch 40 outside pipes will be used. Calculate the pipe length required for this operation.