Pipe connection device

A pipe connection device comprising:

• an adapter comprising a hollow pipe and a ring-shaped protruding end extending in a diameter direction of the hollow pipe from one end of the hollow pipe in a longitudinal direction;
• a ring flange formed in a ring shape and mounted so as to surround an outer circumferential surface of the protruding end and to be axially rotatable about a central axis of the hollow pipe in the longitudinal direction but not to be movable over the hollow pipe in a fully assembled state;
• and
• a fastening unit configured to join the ring flange and a second ring flange of a second adapter having a second hollow pipe to each other in a stacked structure so that one end of the ring flange or the second ring flange of the hollow pipes in the longitudinal direction and one end of the other of the ring flange or the second ring flange of the hollow pipes in the longitudinal direction are forcibly secured to each other,
• wherein the ring flange comprises a plurality of fastening holes formed therein,
• wherein the fastening unit comprises:
• a fastening bolt inserted through one of the plurality of fastening holes in the ring flange and a corresponding fastening hole in the second ring flange;
• and
• a fastening nut configured to secure the fastening bolt to the ring flange,
• wherein the plurality of fastening holes is arranged at regular intervals in a circumferential direction of the ring flange,
• wherein the ring flange further comprises:
• click protrusions protruding from one surface of the ring flange to a preset height or less;
• and
• click grooves formed in the one surface of the ring flange so as to receive click protrusions of the second ring flange, and
• wherein the click protrusions and the click grooves are alternately arranged such that one of the click protrusions or one of the click grooves is located between two adjacent ones of the plurality of fastening holes.