Fluid apparatus unit structure

A fluid apparatus unit structure in which plural fluid apparatus components are connected via flow paths that are to be sealed and each of whose cross-sectional profiles is circular, the components being collected together and integrated onto a base member,

• wherein a casing member for the fluid apparatus components is partitioned into plural members in a base member mating direction, a female threading portion assembly in which plural female threading portions that are arranged at an even pitch in a peripheral direction and that have upper side openings and lower side openings and that communicate in the mating direction are integrated by a ring-shaped linking member, is installed between the base member and base side partitioned members of a casing member at a position in close contact with the base member, and with a base side member interposed therebetween, different linking members are threaded and tightened from both a casing member side and a base member side of the female threading portion while a uniform compressing force from the linking members acts over an entire sealing surface with respect to the base side member by a ring-shaped sealing portion formed on the base member, the ring-shaped sealing portion having at least one of a concave portion and a convex portion.