The Schlenk line is a commonly-used chemistry apparatus developed by Wilhelm Schlenk. It consists of a dual manifold with several ports. One manifold is connected to a source of purified inert gas, while the other is connected to a high-vacuum pump. The inert gas line is vented through an oil bubbler, while solvent vapors and gaseous reaction products are prevented from contaminating the vacuum pump through a liquid nitrogen or dry ice/acetone cold trap. Special stopcocks or Teflon taps allow for vacuum or inert gas to be selected without the need for placing the sample on a separate line.

Schlenk lines are useful for safely and successfully manipulating air sensitive compounds. The high vacuum is also often used to remove the last traces of solvent from a sample. Vacuum gas manifolds often have many ports and lines, and with care it is possible for several reactions or operations to be run simultaneously.