Abstract: A pneumatic tubular conveyor pipeline is provided for conveying solid products for example in granular or chunk form. The conveyor pipeline comprises an outer impervious pipe and an inner porous pipe arranged so as to form an annulus therebetween. The annulus is divided into chambers having unidirectional pressure responsive vents. An air pressure source is connected to the first chamber. A feed apparatus is connected to the feed end of the inner pipe for injecting the product into and propelling same through the inner pipe. The chambers' vents consecutively open as the underlying portions of the inner pipe become filed with the product.