The driving forces of this change are lower prices, better sanitation and environmental concern. Additional reasons are improvement of the properties of the plastics, such as increased resistance to pressure and heat. Among other plastic materials, PP-R pipe became most widely used for hot water systems due to its good quality aspects and advantages in installation as well as reasonable economics. The demand for PP-R pipes has increase rapidly not only in Europe where the demand initially began, but also in the Middle East and China. PVC , one of the most widely used materials in manufacturing pipes, is being replaced by PE and PP for environmental reasons.