Our yellow perforated flexible ducting is used for ducting gas supply services, usually yellow MDPE pipes, when connecting from the boundary to the house in a single way corrugated pipe. It is available in coil diameters of 63mm, 80mm, 110mm and 160mm. These measurements refer to the outside diameters (O.D.), all dimensions can be found in the table alongside the product image.The perforations in the duct allow gas to vent safely in the event of a leak. The ribbed external wall ensures that the duct can withstand high compressive forces.You should always choose a diameter that allows plenty of room within the duct to allow the gas pipe to be drawn through smoothly.All full coils come with an integral coupler. The coupler enables two coils to be connected together as required.This coil is manufactured to BS4962 and it complies with Transco specifications.