PURPOSE: To collect and recover a liquid leaked from a pipe connection part in a pipe line.

CONSTITUTION: The first cover unit 1 is mounted on a half peripheral part of pipes 100, 200 astride a pipe connection part B on both sides of this connection part B, and the second cover unit 3 is mounted on the other half peripheral part of the pipes 100, 200 astride the pipe connection part B on both sides of this connection part B. A liquid leaked from the pipe connection part B is collected in a space surrounded by the first/second cover units 1, 3. The collected liquid is recovered through a liquid bleeding hole part 5 formed in the second cover unit 3. The hole part 5 is desired to be left as provided in a successively providing part between a peripheral wall part 31 and a side wall part 32 of the second cover unit 3.