Thanks to its good mechanical, electrical and optical properties, as well as good chemical resistance, rigid PVC is very useful for many applications. It is used in plant and machinery applications for pressure pipes, couplings and fittings, blowers and fans, air ducting, valves, pumps, or in the chemical industry for tanks and liners made of rigid PVC (PVC-U). In the building industry rigid PVC is used e.g. for wastewater pipelines, roof gutters and downpipes, gas pipes, drainage pipes, window frames, facade elements, ventilation shafts and anti-glare screens. In electrical technology, rigid PVC is used for insulating conduits, transparent distribution-box covers, housings and cable conduits. Examples of rigid PVC applications in the packaging industry include diffusion-resistant bottles for oils and other liquids.