Pipework is the pipes that belong to a building, a machine, or some other structure, taken as one system — not a single pipe, but the whole set running through walls, under floors, or around an engine. In a house it is often the water and heating pipes; in a factory, a ship, or a power plant it may carry steam, oil, gas, or waste. British speakers use this word a lot. Americans more often say piping, or just the pipes. It can sound like a builder’s or an engineer’s word, the sort of thing you read in a report, though actually ordinary people do say it when they mean “all those pipes, the whole lot.” The picture stays practical: tubes that carry something from one place to another, fitted into a place or a machine.

管線（整組管道，不是單一根）