A Mature Tube Verified

Respect the tube. Let it age. And listen to the water running through it; it sounds different than it did a hundred years ago. It sounds like home.

It carries its load not with the arrogance of newness, but with the silent confidence of age. In a world obsessed with replacement and upgrade, the mature tube stands as a monument to the radical idea that some things—in fact, the most important things—get better with time. a mature tube

As the tree ages, the inner tubes undergo tylosis . The tree deliberately plugs its oldest, largest central tubes with balloon-like cellular outgrowths. To a human engineer, "plugging" a pipe sounds like failure. To a tree, it is the ultimate success. By sealing off the oldest mature tubes, the tree converts them into structural columns of lignin. They no longer carry water, but they now carry the weight of the canopy. Respect the tube

Heat exchangers are the unsung heroes of power plants and refineries. They consist of thousands of metal tubes. A brand new stainless steel tube is actually quite bad at transferring heat. Why? Because it is too reflective and too clean. It sounds like home

Every material has a ductile-to-brittle transition. For cast iron (used in water mains since the 1800s), a mature tube is a happy tube until about year 80. At year 80, the graphite flakes within the iron have fully spheroidized. The tube is at its peak tensile strength. At year 81, graphitic corrosion begins. The iron literally turns into graphite powder, leaving a tube that looks like metal but crumbles like chalk when touched.