Coolingwateroutletreturnsystem

That's quite a word....
But: it's a huge system with huge valves and piping.
Here you can see more of the lay out of the system.
The lower pipes are the outletpipes which lead te coolingwater back to the sea.
The upper pipes are meant for circulation; that is for thermoshock in summer or keeping the ice away in winter.
Piping has a diameter of two meters.... so are the electrically driven valves.
You are looking at two valves in one pipe; one blockvalve and one for regulating.

Better in LARGE....