Vacuum freeze-drying is a technique used in water damage restoration where wet documents like books and paper are frozen inside a negatively pressurized chamber.
Vacuum pressure refers to the negative pressure usually related to the airflow of an extraction unit like vacuum cleaners, sub-surface flood extractors or a vacuum freeze-drying chamber.
A vapor barrier is a water-resistant material that is used to prevent moisture and vapor seepages into a structure, particularly basements.
Vapor pressure refers to the pressure, measured in pounds per square inch, that is the force exerted by a vapor. Confined liquids can vaporize and the accumulation of vapors above the liquid causes the vapor pressure to approach fixed limits called maximum or saturated vapor.
Vapors are diffused substances or the gaseous form of substances, which are normally in the solid or liquid state at room temperature and pressure. Evaporation is the process where liquids are transformed into gas or vapors. Vapors can be changed back into the solid or liquid state through pressurization or temperature drops. Solvents with low boiling points are called volatile and easily changes to the vapor state. Examples are benzene, alcohol, mercury and toluene.
In environmental concepts, velocity refers to the speed of water flowing in a particular waterway, such as rivers or streams. It also refers to the speed of the water flow of a flood.
A veneer is a thin layer of material, usually made of wood, plastic or metal, which is glued to another material or substrate to provide strength and durability. It is also used to provide decorative features in a surface.
Ventilation is an important procedure in restoration work wherein the vapor and gases inside an enclosure are flowed either by natural convection or forced. Ventilation can be achieved through existing openings like windows and doors, or though external equipment.
The venturi effect is the creation of a partial negative pressure or vacuum using a constricted flow of fluid or gas through a section of a pipe.
Vinyl material is composed of thermoplastics and is constructed from chlorides through the process of polymerization.
Vinyl Asbestos Tile (VAT)
VATs are tiles that contain asbestos and these were widely used as floorings in schools, hospitals, and other public buildings before the 1980s. Usage was discontinued when the hazardous effects of asbestos were established.
Vinyl Composition Tile (VCT)
VCTs are glass-fiber finished flooring materials that are widely used in commercial and institutional structures. Vinyl Composition Tiles replaced the asbestos tile as the flooring of choice for high-traffic areas due to its low cost and easy maintenance requirements. VCTs are applied to smooth and leveled sub-floors using a specialized vinyl adhesive. After installation, VCTs are waxed and then these are buffed using specialized tools and materials to produce an excellent interior finish.
Viruses are very small microorganisms that invade body cells. A virus feed on host cells and eventually kills them. Common diseases known to be caused by viruses include colds, influenza, hepatitis, HIV, herpes, measles, rabies, mumps, rubella and small pox.
Viscosity is the property of a fluid that resists the force causing fluids to flow. Counteracting forces are released that creates resistance to the internal flow of a fluid. For most liquids, viscosity increases as the temperature drops.
Visqueen is used as a vapor barrier and is made of polyethylene.
Visual inspection is the examination or investigation of a site or area affected with damage and this is performed without the use of instruments.
Volatile Organic Compound (VOC)
A volatile organic compound is any carbon-based organic matter that has the properties of easily liquefying into a gaseous matter at room temperature. VOCs are found in various products such as building materials, cosmetics, household cleaners and electrical equipments. This includes paint, solvents, aerosols, cleaners, and air fresheners. Although exposure to VOC usually results in symptoms similar to colds, some believe VOCs to be carcinogenic and can be a serious health risk.
Volatility refers to the tendency or ability of a fluid to change into the vapor state. Fluids with a well-known tendency to vaporize rapidly are called volatile liquids. Examples are alcohol and gasoline.
Volt / Voltage
A volt is a measure of electrical potential. Current is measured in amperes.
Vulcanization is a chemical process performed on rubber compounds and these are used in a variety of industrial and commercial purposes. With vulcanization, rubber compounds lose the plasticity properties and become irreversibly hardened after processing.