FABRIC FINISH
See "Fabric Impression." The term "Cloth Finish" is used interchangeably.
FABRIC IMPRESSION
A pattern in the rubber surface formed by contact with fabric during vulcanization (usually during Drum Curing).
FATIGUE
The weakening or deterioration of a material occuring when a repetition or continuous application of stress causes strain.
FIELD ASSEMBLY
A joint that is assembled at the jobsite due to its size ( too large to ship ) or the location of the breach opening makes it more practical to install in sections.
FILLER
Any compounding material, usually in powder form, added to gasketing materials either to improve quality or reduce cost.
FINISH
See "Surface Finish".
FINISH (see RMS)
Surface condition of materials for metals, measured in terms of RMS.
FLANGE
Rim or edge projecting at right angles to provide strength, or a means of attachment to another part.
FLANGE JOINT
A joint formed by two abutting flanges.
FLANGE PACKING
See Hat Packing.
FLANGES
That part of an expansion joint used for fastening the joint into the system. Can be either metal or same materials as the bellows.
FLEX LIFE
The relative ability of a rubber article to withstand cyclical bending stresses.
FLOW DIRECTION
Direction of media (fluid, gas, air, etc.) movement through the system.
FLOW LINER (BAFFLE)
A metal shield that is designed to protect the abrasive media in the stream and to reduce flutter caused by the air turbulence in the gas stream. Flow Liner/Baffles may be welded or bolted into position.
FLOW METER
A device used to measure the flow rate of a fluid through a pipe. In packing applications a flow meter may be used to measure the amount of flushing fluid that is entering and/or leaving the stuffing box.
FLUID SIDE
The side of the seal which in normal use faces toward the fluid being sealed.
FLUSH PORT
A hole in the side of a stuffing box through which a cleansing or lubricating fluid is injected.
FLUSHING FLUID
A clean liquid (usually water) which is injected through a flush port to exclude solid particles from the stuffing box area and minimize abrasive wear. A flushing fluid might also be used to cool the packing in a high temperature application, or to keep air from being drawn into a pump in a suction application.
FLUTTER
The action that occurs on the joint body caused by turbulence of the system media or vibration set-up in ducting system.
FOLLOWER
See "Gland Follower".
FORCE POUNDS
The total load required to deflect an expansion joint a distance equal to the maximum rated movement of the product.
FOREIGN MATERIAL
Any extraneous material such as dirt, sand or metal that should not normally be present in or on a product.
FPM
Abbreviation for "Feet per Minute", a measure of the surface speed of a rotating shaft.
FRAME
The complete angle iron or plate frame to which belt of bellows portion of the expansion joint is attached.
FRICTION
Resistance to motion due to the contact of surfaces which normally generates heat.
FRICTION COATING
A rubber covering applied to the weave of a fabric simultaneously with impregnation.
FRICTION FACTOR
An empirically determined factor used to estimate the frictional force generated by the packing on a valve stem. It is important to note that this is not the same as "Coefficient of Friction".
FSA
Fluid Sealing Association, an American-based trade association for the mechanical packing industry.
FSA (FLUID SEALING ASSOC.)
The name of the American-based trade association for the Mechanical Packing Industry.
FUGITIVE EMISSIONS
An unintentional gaseous or liquid leakage given off by a piece of equipment. See also "Emissions".
FULL-FACE GASKET
A gasket covering the entire flange surface and including bolt holes.
FUNCTIONAL LIP DIAMETER
The apparent inner diameter of the seal when the seal case is concentric with the outer diameter of the sizing mandrel in an air gage, light box, or similar inspection equipment.