Reference
Definition
What the word means. This is not a work instruction.
Good flex is short, supported, pulled reasonably straight, not kinked, not crushed, sealed at the inner core, insulated at the jacket, and routed without blocking access. Bad flex sags, loops, pinches, or gets stretched over obstacles like a rope.
Air does not like tight bends, crushed inner core, or lazy sag. TAB will punish bad flex later.