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.
1 Vacuum pressure safety valve (VPSV): An automatic system that relieves by the static pressure of a gas. The relieving pressure is small, negative and near the atmospheric pressure.  Low and vacuum pressure safety valve (LVPSV): An automatic system that relieves by the static pressure of a gas.