Piping
Piping turns up in 2 fields: geosynthetics, textiles. Here is what it means to the people in each one.
Piping in geosynthetics
Soil particles washing through a filter or out of an embankment, leaving voids and channels behind.
When a geotextile's openings are too large for the soil, or a filter is missing altogether, seepage carries fines away and erodes a growing pipe back into the soil. It shows as sinkholes behind walls, muddy drain discharge and settlement over drains. Retention criteria in filter design exist to stop piping, while permittivity and gradient criteria stop the opposite problem, clogging.
"Muddy water out of the weep pipes and a sinkhole behind the wall, that's piping, the fabric's too open."
Piping in textiles
A narrow tube of fabric, often containing a filler cord, sewn into a seam for decoration or structure.
A trim made by folding a strip of bias-cut fabric over a piece of cord and sewing it into a seam. It leaves a raised, rounded line along the edge or join of a garment, upholstery, or accessory. It adds structural stiffness to edges and provides a contrasting visual outline.
"Baste the piping to the right side of the front panel before attaching the back, so the cord stays tight against the seam line."