CATHODIC PROTECTION— A method for pre- venting the corrosion of metals by electrolysis. CENTRIFUGAL— Moving or tending to move away from the center axis of a rotating or turning object. CENTRIFUGAL PUMP— A rotating device that moves liquids and develops liquid pressure by im- parting centrifugal force. CENTRIFUGAL PURIFIER— A rotating device that cleans fuel by using centrifugal force. CLEAR AND BRIGHT— Term for uncontaminated fuel; indicating a complete absence of haze, free water, or particulate matter that would be visible to the naked eye. CLEAVAGE— The point of interface between two dif- ferent liquids, such as oil and water. CLOUD POINT— The temperature at which a fuel develops a cloudy or hazy appearance due to the precipitation of wax or moisture. COALESCER— A tube (unit or element) that unites water droplets when fuel passes through it. COFFERDAM— The space surrounding the MOGAS storage tanks aboard ship; a watertight box. COMBUSTIBLE LIQUID— A liquid having a flash- point at or above 100°F. COMMINGLING— Tie mixture of two or more pe- troleum products resulting from improper handling, particularly in pipeline or tanker operations. CONSOLIDATE— To merge into one. To consolidate a nest of tanks means to pump the remaining fuel from several partially empty tanks into a single tank. CONTAMINATION— The addition of some material not normally present in a petroleum product, such as dirt, rust, water, or another petroleum product. CONTINUITY— To have a complete, uninterrupted electrical circuit. CORROSION— The process of dissolving, especially of metals, due to exposure to electrolytes. CRUDE OIL— Petroleum in its natural state. CV— Aircraft Carrier. CVN— Aircraft Carrier (nuclear-powered). DAY TANK— Fuel storage tank used for daily issue of fuel. DEADMAN CONTROL— A control device requiring manual operation, such as a switch or valve, de- signed to stop flow if the operator releases it. DIAPHRAGM— Separating device of rubber compo- sition used to regulate all hydraulically operated valves. DIFFUSE— To spread widely, scatter, DIFFUSER— A mechanical device used to diffuse. DIKE— An embankment or wall, usually of earth or concrete, surrounding a storage tank to impound the tank’s contents in case of a leak or spill. DISSOLVED WATER— Water absorbed into the fuel that is not visible. The amount of dissolved water a fuel will hold depends upon the fuel’s temperature. DISTILLATE— Common term for several fuels ob- tained directly from distillation of crude petroleum; typically includes kerosene, JP-5, light-diesel, and other light-burner fuels. DOUBLE-WALLED PIPING— Piping with two in- dependent chambers, one surrounding the other (an inner and an outer). Typically used in shipboard gasoline systems. The inside chamber carries the fuel, the outside chamber holds a protective gas (such as CO? or N?). DOWNGRADE— To designate a fuel for a lesser pur- pose than originally specified, often because of contamination. EARTHING— See GROUND. EDUCTOR— A jet-type pump with no moving parts. An eductor moves liquid by entraining the pumped liquid in a rapidly flowing stream of water (venturi effect). Normally used to dewater bilges and tanks. EMULSION— The suspension of fine droplets of one liquid in a second liquid with which the first will not mix. ENTRAINED WATER— Free-water contaminant in a fuel in the form of very small droplets, fog, or mist. It may or may not be visible. EVAPORATE— To change into vapor. EVAPORATION LOSS— Loss of liquid petroleum into the atmosphere caused by evaporation. FILTER— A porous object through which a liquid is passed to remove unwanted particles of solid matter. AI-2