An apparatus and system for transferring a liquid, such as an anesthetic, from a reservoir to a machine while effectively minimizing the release of the liquid to the surrounding environment. The apparatus can include a first and a second component wherein twisting the first component and second component relative to each other causes a protrusion to seal or unseal a through-hole thereby allowing or preventing the flow of fluid and wherein a portion of an exterior surface of the second component that mates with a vaporizer has a polygonal shape with three or more flat sides.
