Our polyester pipes are manufactured by applying a continuous spinning process, which is, at present, the state-of-the-art polyester pipe manufacturing process. This process allows for continuous introduction of reinforcement in the circumferential direction. This technology results in a very compact laminate that enhances the effects of all the three basic raw materials: glass fibres, silicate sand filler and polyester resin. The pipe strength is significantly increased due to glass yarn and chips. Sand filler in the core serves to increase the wall thickness and in turn to increase pipe stiffness. The system to apply resin into the outer and inner layer supports the use of different special resins for special purpose applications. As an example, the inner surface may be lined with resin suitable for handling corrosive substances, while the structural and outer laminate layers are treated with standard polyester resin.