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.
Butterfly Valves. In butterfly valves, the flow is regulated through a disc-type element held in place in the center of the valve by a rod. Similar to ball valves, valve operation time is short because the valving element is simply rotated a quarter turn (90Â°) to open or close the passageway.