We walk through what these things really are, how they differ from suction hoses, the three-layer logic underneath most of them, why so many types exist (layflat, vinyl, rubber, reinforced), what users tend to weigh when matching one to a job, and a few common misconceptions worth pushing back on.

There's an idea at the heart of all of it: the hose is named for where it sits, and where it sits decides everything else. The position determines the construction. The construction determines the rating. The rating determines whether the hose can do the work. Once you see it that way, every choice on the spec sheet starts to make sense — including the fittings at the ends, which catch out more people than the hose itself does.

A general-principles primer for buyers, plant operators, contractors, and specifying engineers.