Piping: decorative trim versus fluid transport

To most people, piping is the narrow cord trim stitched along the edges of cushions, collars, or lapels. It serves no structural purpose, only decoration. A contrasting fabric wraps a cord core, and the tailor stitches it down to frame seams or openings. The piping might be bright red on a navy jacket, or navy on white. It is purely aesthetic.

In manufacturing, piping is something entirely different. Piping means the system of tubes, usually metal or plastic, that carries fluids or gases through a plant: water, steam, compressed air, hydraulic fluid, coolant. A single pipe is a tube. Piping is the assembled network of pipes, fittings, valves, and joints that form the distribution system. Piping can be rigid steel welded at the seams, or flexible tubing clamped or threaded together. The piping must withstand pressure, temperature, corrosion, and vibration.

The garment trades also use the word piping to describe the act of forcing icing, batter, or paste through a nozzle to decorate or shape food or cake. A pastry chef pipes meringue onto a plate. This sense comes from the cord piping: the comparison is to threading something thin and continuous through a narrow opening. The piping bag creates a continuous decoration much as the garment piping creates a continuous trim.

All three senses share a core idea of passage or channeling through a narrow, constrained opening. The fashion piping threads cord through fabric. The manufacturing piping threads fluid through tubes. The pastry piping threads paste through a cone. The word began in the textile trades, where the cord itself was called a pipe, perhaps because it was hollow or tubular. The verb piping grew from that noun. When manufacturing plants needed a word for fluid distribution lines, they borrowed piping from the language already familiar to them, applying the old word to a new industrial system.