To provide a pipe fitting and a piping unit whereby the pipes are free of rotation and their coupling will never loosen even if an external force acts on the coupled pipes from any side on the circumference.

Female fitting members 15 are formed at the ends of each slurry pipe 11, and the bends 14b of these female fitting members 15 are facing back to back, and therefore the slurry pipes 11 will never rotate even if an external force acts on these pipes 11 from any side on the circumference after pipes 11 are coupled together through a joint pipe 12 where male fitting members 13 are provided at the ends. As a result, the coupling part of the slurry pipes 11 is free of any risk of loosening, and there is no risk that the slurry flowing therein leaks to outside nor the coupled pipes 11 slip off from each other.