To provide a piping connection device capable of improving sealing performance between a casing and a housing without changing piping members, or making structure larger.

In a sleeve 80, a cylinder part 54 of a housing main body 32 is inserted into a first containing part 81 existing on one end part side in an axial direction, and a second cylinder part 72 of a fastening member 70 is inserted into a second containing part 82 existing on the other end part side. By installing the sleeve 80, force applied to a piping member 100 goes from the fastening member 70 through the sleeve 80 into the housing main body 32 before it is transmitted to the casing 60. Therefore, inclination of the casing 60 to the first cylinder part 54 is reduced. As a result, surface pressure applied to the seal member 51 and the seal member 52 becomes uniform, thereby sealing performance between the housing main body 32 and the casing 60 is improved.