The Aggregates & Recycling Information Network

Glossary: V

  • Vane Pump

    A pump having a slotted rotor mounted eccentrically in the circular casing, and vanes which are free to slide radially in the slots, forming pockets of variable volume between them.

  • Variable Costs

    Costs which vary directly with output.

  • Variable-ellipse Screen

    A mechanically vibrated screen in which the vibrating assembly is mounted above the screen and the motion generated varies along the length of the screen; a flat ellipse at the feed end, a circle at the centre and a steep ellipse at the discharge end.

  • Vector

    A line used to represent a vector quantity, ie to represent that quantity in both magnitude and direction.

  • Vector Quantities

    Quantities which possess two fundamental characteristics, namely magnitude and direction. Examples are force, velocity and alternating electric current and voltage.

  • Vee Belt

    A power transmission belt having a cross-section in the form of a truncated V running in similar-shaped grooves in pulleys. These belts can withstand higher working stresses and can transmit much more power than a flat belt of corresponding cross-section.

  • Vein

    A mineral body, thin in relation to its other dimensions, which cuts across the bedding and in which the minerals are later than the country rock.

    Also: lode 

  • Velocity

    The speed of an object in a specified direction.

    Units: m/s

  • Velocity Of Detonation

    The velocity with which the shock wave traverses an explosive charge on detonation.

    abbr. VOD

  • Velocity Ratio

    The ratio of the distance moved by the effort to the distance moved by the load. 

    Also: movement ratio

  • Venturi

    A convergent-divergent duct in which the kinetic energy of a fluid flow is increased at the throat, leading to a drop in pressure energy there; after the throat the reverse takes place. The lower pressure at the throat compared with the pressure in the pipe can be used as a measure of flow rate.

  • Venturi Scrubber

    A device for removing dust from gases by passing them through a narrow throat into which water is introduced and is atomized by the high-velocity gas stream. Dust particles are trapped in the water droplets and are then carried away by the flow to a centrifugal separator.

  • Vermiculite

    A variety of chlorite occurring in the form of radiating tubes or granules. Expanded vermiculite is used as a lightweight aggregate in concrete.

  • Vertical Circle

    The graduated circular plate used for the measurement of vertical angles by a theodolite.

  • Vibratory Roller

    A self-propelled or towed roller with one or more mechanically vibrated rolls which impart the oscillations to the material being compacted.

  • Viscometer

    An instrument for measuring viscosity.

  • Viscosity

    The resistance of a fluid to flow or relative movement within itself; the higher the viscosity, the thicker or less free flowing is the fluid.

  • Viscosity Grade

    The degree of viscosity of a binder measured by a standard viscosity test.

  • Viscosity Index

    The higher the index, the more the viscosity changes with temperature. Values range from 0 to 100.

  • Vitreous Lustre

    The lustre of glass, eg quartz.

  • VOD

    abbr. velocity of detonation

    The velocity with which the shock wave traverses an explosive charge on detonation.

  • Void

    In an opencast mine, the open excavated area.

  • Volcanic Rock

    Igneous rock extruded at the Earth’s surface.

  • Volt

    The difference of electrical potential or emf between two points of a conducting wire carrying a constant current of one ampere, when the power dissipated between these two points is one watt.

    Symbol: V

  • Voltage

    The electromotive force of a supply of electricity.

    Symbol: V

    Unit: volt 

  • Voltage Drop

    The fall in voltage between the ends of a conductor or across an apparatus through which a current is flowing.

  • Voltmeter

    An instrument for measuring the voltage or potential difference between two points in a circuit. It is connected across the points being measured.

  • Vug

    A natural cavity within a mass of rock usually lined with crystallized mineral.

  • Vulcanization

    The treatment of rubber with sulphur compounds in order to change its physical properties; a process used in the manufacture and repair of tyres, conveyor belting etc.