E-COATING
A coating process where an electric charge is used to bond the paint to the metal outer ring for Garlock spiral wound gaskets. The result is a smooth, drip-free finish with superior chip resistance. The process is also environmentally friendly, as no ozone-depleting propellants are used in the process.
ECCENTRICITY
The distance that the central axis of a shaft is offset from the center of the stuffing box through which it passes.
ELASTIC LIMIT
The limiting extent to which a body may be deformed and yet return to its initial shape after removal of the deforming force.
ELASTOMER
An elastic rubber-like material which, in the vulcanized state and at room temperature, can be stretched repeatedly to at least twice its original length. Upon release of the stress, this material will immediately return to approximately its original length.
ELONGATION
The increase in length expressed numerically as a fraction or percentage of the initial length.
EMISSIONS
Gaseous or liquid leakage given off by a piece of equipment. This usually refers to volatile organic hydrocarbons monitored by government agencies. It is typically expressed in parts per million volumetric (ppmv, or simply ppm).
END PLAY
A measure of axial movement encountered or allowed, usually in reference to the shaft on which the seal lip contacts.
END RING
A ring used at the top or bottom of a packing set, usually functioning as a wiper ring and/or an anti-extrusion ring. See also "Anti-extrusion Ring", "Junk Ring", and "Wiper Ring".
EPA
Abbreviation for "Environmental Protection Agency", the US government agency responsible for enforcing the regulations imposed by the Clean Air Act Amendment.
EPA METHOD 21
A method established by the EPA for performing emissions measurements on equipment such as valves, pumps, and flanges.
EXCLUSION DEVICE
A device capable of excluding contaminating particles and fluids that would otherwise be dragged back into the primary sealing area of the equipment.
EXCURISION TEMPERTURE
The temperature the system could reach TEMPERTURE: during an equipment failure such as an air heater failure. Excursion temperature should be defined by maximum temperatures and time duration of excursion.
EXPANSION
The increase in any linear dimension or volume.
EXTERNAL ARCH CORNER
An expansion joint corner with the arch formed outwardly that is designed primarily for pressure service, generally used in conjunction with a rectangular or square expansion joint.
EXTERNAL PRESSURE
Pressure (Lbs./Sq. Inch) exerted on the OD of a seal.
EXTRACTION TEST
A test involving the separation of certain components from a solid by dissolving them in a liquid solvent under suitable conditions.
EXTRUSION
The distortion, under pressure, of a portion of a seal into the clearances between mating metal parts.