Eccentric - not having the same center; not concentric, such as an eccentric pipe reducer, or an eccentric pump suction nozzle
Eccentricity (shaft) - The variation of a shaft surface at its outer diameter (OD) when referenced to its true geometric centerline; a measure of a shaft's out-of- roundness.
Eddy current - the electrical current that is generated in a conductive material when such material intercepts the electromagnetic field, example, in a proximity probe.
Efficiency - the ratio of output horsepower over input horsepower of a machinery.
Elasticity - the property of a material that allows it to change its shape in direct response to an applied force, and its ability to restore its original shape when the force is removed; the state of being elastic or flexible.
Elastomer - an elastic material , or substance, either occurring naturally, or synthetically produced.
Electrical runout - A source of error on the output signal of a proximity probe (transducer) which repeats with each shaft revolution.
Enamel-lined - the characteristic of a wetted surface of being coated with enamel, or some form of enamelling material, to obtain a smoother surface finish to help improve the pump efficiency, or a harder surface finish to make it more resistant to abrasion.
End-suction pump - a pump whose suction nozzle is parallel and adjacent to the non-drive end (NDE) of its shaft. The liquid enters the suction nozzle and feeds straight into the impeller eye. See top suction pump.
End-user - the ultimate user of an equipment, as opposed to a buyer, consultant, or contractor who are representing, or acting in behalf of, the ultimate user.
Entrance suction loss - of, or pertaining to, the hydraulic losses at the suction nozzle up to the entrance of the (first stage) impeller of a pump. The entrance suction losses affect the NPSHR. (Also referred to as suction entrance loss.)