Plastics piping systems for pressure and non-pressure water supply, irrigation, drainage or sewerage. Glass-reinforced thermosetting plastics (GRP) systems based on unsaturated polyester (UP) resin. Pipes with flexible joints intended to be installed using jacking techniques|Plastics, Pipes, Sewers, Pipe couplings, Pipework systems, Drainage, Polyesters, Thermosetting polymers, Sewerage, Plastic pipelines, Pipelines, Unsaturated polyesters, Water supply, Jacking pipes, Testing, Performance, Water, Glass fibres, Reinforced materials, Irrigation equipment