Reinforced tube of plastic and a method of manufacturing the same

Abstract From the Canadian patent

A reinforced tube or a tubular pipe comprises an inner tubular first layer of class fiber reinforced plastic an outer, tubular second layer disposed around and spaced radially outwardly from the first layer and also comprising a glass fiber reinforced plastic, and an intermediate filler layer located between the first and second layers and containing plastic and granular filler material which is bonded together and to said first and second layer. In addition a reinforcing insert is embedded in the intermediate filler layer and it comprises a continuous coil wound around the first layer and embedded in the intermediate layer. The coil may comprise a fiber reinforced plastic coil or a steel …