Abstract: An elongated conduit including a tubular outer pipe, an elastic inner pipe and an annulus between the outer pipe and inner pipe, the conduit being provided with a fluid supply device, the outer pipe being provided with an inlet for introducing the fluid in the annulus between the outer pipe and the inner pipe, which inlet communicates with the fluid supply device.

Abstract: The invention provides an elongated conduit (2) comprising a tubular outer pipe (3), an elastic inner pipe (4) and an annulus between the outer pipe and inner pipe, the conduit being provided with a fluid supply device (7), the outer pipe being provided with inlet means (6) for introducing the fluid (9) in the annulus between the outer pipe and the inner pipe, which inlet means communicates with the fluid supply device. The invention also provides a method to remove a blockage in the inner pipe of said elongated conduit. In addition, the invention relates to a method for transporting a liquid, semi-liquid, paste-like or solid material through the inner pipe of said elongated conduit.