A belt is a loop of flexible material used to link two or more rotating shafts mechanically, most often parallel. Belts may be used as a source of motion, to transmit power efficiently or to track relative movement. Belts are looped over pulleys and may have a twist between the pulleys, and the shafts need not be parallel.
A valve is a device that regulates, directs or controls the flow of a fluid (gases, steam, liquids, fluidized solids, or slurries) by opening, closing, or partially obstructing various passageways. Valves are technically fittings, but are usually discussed as a separate category. In an open valve, fluid flows in a direction from higher pressure to lower pressure.
Valves may be operated manually, either by a handle, lever, pedal or wheel. Valves may also be automatic, driven by changes in pressure, temperature, or flow. These changes may act upon a diaphragm or a piston which in turn activates the valve. More complex control systems using valves requiring automatic control based on an external input (i.e., regulating flow through a pipe to a changing set point) require an actuator. They can be electromechanical actuators such as an electric motor or solenoid, pneumatic actuators which are controlled by air pressure, or hydraulic actuators which are controlled by the pressure of a liquid such as oil or water. An actuator will stroke the valve depending on its input and set-up, allowing the valve to be positioned accurately, and allowing control over a variety of requirements.
A vacuum breaker is an attachment commonly placed on a bibcock valve or toilet or urinalflushvalve, that prevents water from being siphoned backward into the public drinking water system. This prevents contamination should the public drinking water
system's pressure drop.
A vacuum switch is an electronic or mechanical device that provides an electrical switching contact function at a defined vacuum gas pressure level. It's used in many vacuum applications for pressure control purposes and safety interlock functionality.
A a vent is an opening through which air and other gases can pass.
A Venturi is a tubular setup known as a Venturi tube. Fluid flows through a length of pipe of varying diameter. Venturi tubes are used in processes where permanent pressure loss is not tolerable and where maximum accuracy is needed in case of highly viscous liquids.
Some refrigerators and extra low temperature freezers require the installation of a condensate vaporizer. The vaporizer is a mechanical device that turns water into steam and then transmits that steam into the surrounding atmosphere.
A vessel is container typically used to store, prepare, and serve food. Vessels may be round, square, or rectangular and may be designed as drop-in components of foodservice equipment such as prep top refrigerators (pizza and sandwich units), steam tables, buffets, dessert equipment, and more. Vessels may be plastic, stainless steel, or ceramic and are frequently designed for use with matching covers.
A variator is a device that can change its parameters, or can change parameters of other devices.
A varistor is an electronic component with an electrical resistance that varies with the applied voltage. Also known as a voltage-dependent resistor (VDR), it has a nonlinear, non-ohmiccurrentvoltage characteristic that is similar to that of a diode. In contrast to a diode however, it has the same characteristic for both directions of traversing current. At low voltage the varistor has a high electrical resistance which decreases as the voltage is raised.
Voltage, electric potential difference, electric pressure or electric tension is the difference in electric potential between two points. The difference in electric potential between two points (i.e., voltage) in a static electric field is defined as the work needed per unit of charge to move a test charge between the two points. In the International System of Units, the derived unit for voltage is named volt.