According to one example, a valve for an apparatus configured to mix bone cement is disclosed. The valve can include a base defining a first portion of a passage. The passage can be configured to allow a component of the bone cement through the valve. The valve can include a projection extending from the base to a base opposing end and forming a second portion of the passage that communicates with the first portion. The projection can have a frustoconically shaped surface that comprises one of an outer surface or an inner surface that forms a part of the second portion of the passage.
