The deuterium control conduit was an essential component of a starship's warp propulsion system. This system was maintained by a chief engineer and his staff when a ship was not at warp.

In 2365, aboard the USS Enterprise-D, Chief Engineer Geordi La Forge completed some long overdue routine adjustments on this component. During the couple of hours or so he did these adjustments, he used a SCM model three. (TNG: "The Dauphin")