SEWER DRAIN system has been designed to use a logical size progression from 82mm to 315mm with a single wall thickness to diameter ratio of SDR 41 SN4 and SDR 34 SN 8. A more accurate system using the extra available sizes can be designed, often resulting in considerable cost saving. Pipes are normally available and are supplied with plain, solvent weld and integral push fit joints. The range of products are manufactured according to BS EN 1401 Standards with Kitemark Certification. Application: uPVC pipes are a proven part of modern building and infrastructure for sewerage, underground drainage and road crossing duct application.