Chapter V: V Volatiles

V

Symbol for the element vanadium. Abbreviation for volume ( V or v). Symbol for the shearing force in beam ( V). Symbol for velocity ( v).

vacuum deposition

Also known as vacuum coating and vacuum metallizing. The process adding a protective coating, often aluminum, to a base material, usually another metal or a plastic, by evaporating a metal under high vacuum and condensing it on the surface of the base material. The coatings obtained range in thickness from 0.01 to as many as 3 mils. The process is used for inexpensive jewelry, electronic components, etc.

vacuum melting

A metal process involving the melting of metals in a vacuum to prevent contamination from air and remove gases already dissolved in the metal. Following melting the solidification may also take place in a vacuum or at low pressure.

valley

A term related to the measurement of surface texture, the point of maximum depth on that portion of a profile that lies below the centerline and between two intersections of the profile with the centerline.

valve, ball

A check valve having a control element incorporating a ball seated in the opening in the direction of flow. Reversal of flow seats the ball and clogs the flow.

valve, check

A valve designed to permit flow in one direction.

valve bronze

Alloys nominally containing 83-89% copper, 3-6% lead, 4-5% tin, and 3-7% tin.

valve, needle

A valve having a needle, or semi-pointed control element that seats in...