EDUCTOR: A jet-type pump (no moving parts) which uses a flow of water to entrain and thereby pump water.

EFFICIENCY: The ratio of output power to input power, generally expressed as a percentage.

ELASTICITY: The ability of a material to return to its original size and shape.

ELBOW-ELL: A pipe fitting that makes an angle between adjacent pipes, always 90 unless another angle is stated.

ELECTRICAL ENERGY: Energy derived from the forced induction of electrons from one atom to another.

ELECTRODE: A metallic rod (welding rod), used in electric welding, that melts when current is passed through it.

ELECTROHYDRAULIC STEERING: A system having a motor-driven hydraulic pump that creates the force needed to actuate the rams to position the ships rudder.ELECTROLYSIS: A chemical action that takes place between unlike metals in systems using seawater.

ELECTROLYTE: A solution of a substance which is capable of conducting electricity. An electrolyte may be in the form of either a liquid or a paste.

ELECTROMECHANICAL DRAWING: A special type of drawing combining electrical symbols and mechanical drawing to show the composition of equipment that combines electrical and mechanical features.

ELEMENT: (1) A substance which consists of chemically united atoms of one kind. (2) An indivisible part of a logic function or circuit. Fluidic elements are interconnected to form work-ing circuits. (3) Parts of systems; for example, filter element, valving element, and so forth.

EMERGENCY: An event or series of events in progress which will cause damage to equipment unless immediate, timely, and correct procedural steps are taken.

EMULSIFIED OIL: A chemical condition of oil in which the molecules of the oil have been broken up and suspended in a foreign substance (usually water).

ENERGY: The capacity for doing work.

ENGINE: A machine which converts heat energy into mechanical energy.

ENGINEERING LOG: A legal record of important events and data concerning the machinery of a ship.

ENGINEERS BELL BOOK: A legal record,maintained by the throttle watch, of all ordered main engine speed changes.

ENGINE ORDER TELEGRAPH: Electro-mechanical device which transmits orders con-cerning desired direction and general speed of the engines to the engine room. See ANNUNCIATOR.

ENGINE ORDER INDICATOR: A device on the ships bridge which transmits orders to theengine room for specific shaft speeds in revolutions per minute.

ENGINEERING OFFICER OF THE WATCH (EOOW): Officer on duty in the engineering spaces.

EPM (equivalent per million): A term used to describe the chemical concentration of dissolved material; used in reporting sample test results. It expresses the chemical equivalent unit weight of material dissolved in a million unit weights of solution. (The chemical equivalent weight of chloride is 35.5. If 35.5 pounds of chloride were dissolved in 1,000,000 pounds of water, the water would contain 1.00 epm chloride).

EQUILIBRIUM: The state of balance between opposing forces or actions.

EVAPORATION: The action that takes place when a liquid changes to a vapor or gas.

EVAPORATOR: A distilling device to produce fresh water from seawater.

EXPANSION JOINT: (1) A junction in a piping system which allows for expansion and contraction. (2) A term applied to a joint which permits linear movement to take up the expansion and contraction due to changing temperature of ship movement.

EXPANSION TANK: Provides for expan-sion, overflow, and replenishment of cooling water in an engine.

EXPLODED VIEW: A pictorial view of a device in a state of disassembly, showing the appearance and interrelationship of parts.