Polypropylene glass-reinforced polyester is a “dual laminate” piping system where a chemical resistance liner is combined with a glass fibre reinforced outer jacket. The reinforced outer jacket ensures a higher pressure resistance and better mechanical properties. The PP/GRP materials are produced in accordance with the DIN 16965/16966 design standard. A PP/GRP piping system is often used for the following media: caustic soda and phosphoric acid.