Human Immunodeficiency Virus, commonly known as HIV, is a virus that affects the immune system by destroying white blood cells known as CD4 cells. These cells are responsible for fighting disease.
Servovalve, Hydraulic-Description. A hydraulic servovalve is a servo (see Servo, Hydraulic â Description) with a device (either flapper nozzle or jet pipe) used to position the servo. The term electrohydraulic servovalve is often used because servovalves are controlled through an electrical signal.
A valve is a device that regulates, directs or controls the flow of a fluid 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. The word is derived from the Latin valva, the moving part of a door, in turn from volvere, to turn, roll. The simplest, and very ancient, valve is simply a freely hinged flap which drops to