I worked with trucks a lot in my life, past tense thank Huey, and all of them had sedimentors. My diesel Mazda had a sedimentor.
My boat has a same. It's a Vetus.
I am wondering, how a diesel boat engine doesn't have one?! It stands to reason. It is more likely to get condensation in one's tank on a boat than in a truck.

The plugging is simple, fuel hose coming from the tank then sedimentor in - out and so on. There is no magic. Just another filter in the line.
If you google it there is an explanation under 'fuel sedimentor'.
I use this stuff and it works. A tiny amount is needed only to keep the fuel fresh, the bio-bugs out.

Google it.
Allan, on the photo the big s/s thing on the left is my fuel tank, all 75 litres of it. Opposite on the wall is the sedimentor with the glass bowl. It has a tap on the bottom of it like the fuel filter which when undone let's out a bit of - hopefully - diesel, or water if there is any. Drain the water, close the tap, see ya in a month or two. (do the same at the filter!)
It is reasonably small, the bowl l mean, a schooner worth, l never had any water out of it yet. It is, of course, not for removing water from the tank if one had it inundated! Only condensation water.
The other things on the pic is the coolant reservoir, right of the sedimentor and in the right bottom corner the pong box.
I hope it clears it up for you.