Polyethylene 100 is the strongest PE pipe material at present. Minimum required strength (MRS) for PE 100 pipe is MPa and design stress (DS) 8 MPa and is the most appropriate material in those pipe networks up to 32 bars. PE 100 last generation high density polyethylene (HDPE) greatly takes place as an alternative material in lieu of steel in those systems bearing an operating pressure up to 32 bars due to its material and other advantages. In the same wall thickness, PE 100 resists to a higher pressure than the conventional PE materials. In PE materials (PE/PE 80), the upper limit which is 16 bars at the water level has increased up to 25 bars with PE 100. Thus, PE 100 pipe replaces steel and cast iron pipes in water transfer main pipes operating at 16-20-25 bars. At the same operating pressure, a PE 100 pipe has a thinner wall thickness compared to PE 63 and PE 80 pipes. The high design stres of PE 100 has also increased the maximum diameter limit in PE pipes as well. As of the present day, a diameter of 1000mm has been achieved in PE 63 / PE 80 pipes at 10 bars of pressure. Another important issue is that dimensional reduction has been made possible by PE 100 material. A thinner wall thickness creates a smaller iner diameter, thus a pipe of next smaller size is possible for the same flow rate. A thinner wall thickness in the same diameter and a larger iner diameter also reduce the friction, thus saving energy. While calculating the investment costs of a system, material cost and placement-installation cost must also be taken into account. When steel pipes and PE pipes in distribution networks are compared, the following results are revealed: when only the cost of PE and steel pipes, a steel pipe is approximately 3% cheaper. When the system is considered as a whole (material + placement + installation), PE system provides an economy of approximately 13 percent. The colour of PE 100 pipes is blue striped on black background for fresh water applications. PE 100 pipes are delivered in coils in diameters up to 110mm and in straight pipes 6m or 12m long in larger diameters.