Unit 7
Axial load|An external load that acts lengthwise along a shaft.
Belt whip|A condition where excess slack in a drive belt causes it to begin riding up and out of the sheave grooves, primarily on the slack side. The slack side is the side of the belt that exits the drive pulley as it rotates.
Borescope|An optical device that typically uses fiber optics to display an image through a narrow tube, allowing for the inspection of otherwise difficult or impossible areas to see. For example, a borescope is used to examine the inside of a furnace heat exchanger.
Centistoke (cSt)|A metric unit of measurement related to a lubricants resistance to flow, identifying the relationship between simple viscosity and the density of the lubricant.
Diserpsants|In lubricants, an additive used to disperse or disband groups of particles to prevent them from coagulating or joining together.
Dropping point|The temperature at which grease is soft enough for a drop of oil to fall away or flow from the bulk of the grease.
Dynamic seal|A seal made where there is movement between two mating parts, or movement between one of the parts and the seal.
Fire point|The temperature at which oil will burn if ignited.
Flash point|The temperature at which oil gives of ignitable vapors.
Hantavirus|A virus carried primarily by rodents and causing various diseases which often lead to kidney failure or significant damage.
Inhibitors|In lubricants, an additive that slows down or presents an undesirable chemical reaction or similar process.
Ionizing wires|Thin wires in an electronic air cleaner that cause passing particles to become positively charged. The charged particles are then attracted to the negatively charged collector plates, where they then land and remain.
Journal|The part of a shaft, axle, spindle, etc. which is supported by and revolves in a bearing.
Lapped|Honed and/or polished until extremely smooth.
Oxidation|The process of combining with oxygen. All petroleum products react with oxygen to some degree, and the process accelerates as temperature increases.
Pour point|An oil quality related to viscosity. It can be defined as the temperature at which oil first starts to flow. 
Radial load|The side or radial force applied at right angles to a bearing and shaft.
Safety drop time|The time required for a gas pilot valve to recognize the absense of a pilot flame and electrically lock out the main gas valve.
Sheave|A wheel with a groove for a belt to run in; often considered equivalanet to the term pulley. However, the term is also used by some to identify one groove of a pulley with multiple grooves.
Static seal|A seal made where there is no movement between the two adjoining parts or between the seal and the mating part.
Stuffing box|The housing used to control leaking along a shaft or rod. Typically composed of three parts: the packing chamber (also called the box); the packing rings; and the gland follower (also called the stuffing gland).
Thrust|The force acting lengthwise along the acis of a shaft, either toward it or away from it.
Viscosity|The thickness of a liquid or its ability to flow at a specific temperature.
Viscosity index (VI)|A measure of how an oil's viscosity varies with temperature.