A fitting for making a metal-to-metal fluid seal between a first conduit and a second conduit and corresponding first and second fluid passages. The self-routing mechanism includes the approach of determining the routing tag of a packet from the guide of the network and the destination addresses of the packet, and accomplishes the self-routing of the packets by the sorting of the packets. The folding unit is configured as a rotary folding unit provided with a folding cylinder including: a retaining mechanism which retains a sheet on an outer circumferential surface of the folding cylinder; and a folding blade mechanism which projects the retained sheet radially outward. In this embodiment, a flow conditioner configured in accordance with the present invention can be positioned proximate to the air inlet.