Abstract: A fold control mechanism and method is provided in a foldable conduit system for accurately controlling the movement of a diagonal pipe section which extends above and below the pipes in the system. The fold control mechanism includes a first wheel rigidly secured to an extensible boom and a second wheel connected to the first wheel by a flexible connecting means. The second wheel is rigidly connected to the diagonal pipe section, rotates about its own axis, and rotates aproximately 180.degree. about the axis of the first wheel to maintain control of the several pipes in the conduit system during the folding and unfolding operations.