Abstract: A direction changing section of tubing for a pneumatic tube conveyor wherein a carrier with at least one seal ring around it is of a diameter substantially equal to the diameter of the tube. The portion of the section around the curve is of enlarged inner dimension radially of the curve to enable a carrier to move around it along a series of chords and, hence, turn in a tighter arc. A multiplicity of flexible seal members across and along the curved portion extend radially of the curve so as to be engaged by the carrier passing therethrough.