Our yellow unperforated flexible ducting is used for ducting gas supply services, usually yellow MDPE pipes, when connecting from the supply to the boundary. It is available in coil diameters of 63mm and 110mm. These measurements refer to the outside diameters (O.D.), all dimensions can be found in the table alongside the product image.The smooth inner bore resists any snagging of the water main during installation.Some local authorities specify that the duct should be perforated to allow gas to vent safely in the event of a leak – for our perforated gas duct please click here.You should always choose a diameter that allows plenty of room within the duct to allow the gas pipe to be drawn through smoothly.The coupler enables two coils to be connected together as required.The length of this coil is 50m.