If it could have been as late as 1990 or '91, it's possible that what you saw was not a fiction series but actually the game-show Fort Boyard Fort Boyard or the british variation thereof. A youtube video of the intro from an unspecified season, shows the following scene at 1:59
Here, two contestants clad in tight blue clothes, their team colour, is operating a pump and a pipe. There is also a lot of running and a sequence with an "hourglass" being filled with liquid, which might be a separte "pool-like" image. Finally, the location of the show is the real world offshore Fort Boyard, which together with the gameshow props might give the impression of an oceanic research facility.
Hourglass resembling a pool
The real-world fort boyard, location for the game-show.
The show first aired in France in 1990. I have not found information on when it aired in Italy, but an italian pilot episode was produced in 1991, indicating that it may already have had some success in italy in the preceding year. There are however many regional variations of this show, such as the british "The Crystal Maze" which also aired in 1990 but was not filmed on location at Fort Boyard. The Crystal Maze had four "zones" one of which was an industrial chemical plant  The following picture shows the contestants of the crystal maze enter the chemical plant in the first season:
However, nothing resembling the pumps and pipes task seemed to appear in this episode.
Counting against you having recalled Fort Boyard, is the year 1990. Also that the topmost picture in this answer may not be from the first-season opening credits, which would shift your recalled tv-show intro even further, to the mid 90s. As this video of a first season episode demonstrates, the opening back then consisted only of the contestants arriving via boat, though the task props throughout the episode include both chemistry equipment and pools of water.