flange-retained liner / flexible function block between companion flanges and has a set of bolts, or studs, that generally extend through the companion flanges. [ANSI/ISA-75.05.012000] flange-retained liner A liner that is retained in the body of a butterfly valve by the pipe flanges or by a continuous or segmented ring. The segmented ring provides a way to adjust the liner to disk interference so as to achieve improved sealing. The bore of the pipe. flanges is smaller in diameter than the body bore. Therefore, the flanges retain the liner in the body. [ANSI/ISA-75.05.01-2000] flange taps See orifice flange taps. flank 1. On a cutting tool, the end surface that is adjacent to the cutting edge. 2. On a screw thread, the side of the thread. flap valve A valve with a hinged flap or disk that swings in only one direction. flareback A burst of flame from a furnace in a direction that is opposed to the normal flow. It is usually caused by the ignition of an accumulation of combustible gases. flared tube end The projecting end of a rolled tube that is expanded or rolled into a conical shape. flaring Increasing the diameter at the end of a pipe or tube in order to form a conical section. flash 1. In plastics molding, elastomer molding, or metal die casting, a portion of the molded material that overflows the cavity at the mold parting line. 2. A fin of material that is attached to a molded, cast or die-forged part along the parting line between die halves. It may also be attached to a resistance flash-welded, upset-welded, or frictionwelded part along the weld line. flash converter A converter in which all bit choices are made at the same time. flasher A device that causes visual displays to turn on and off repeatedly. Common types of flashing include fast flashing, flashing, slow flashing, and intermittent flashing. [ANSI/ISA-18.1-1979 (R1992)] flashing 1. Steam that is produced by discharging water at saturation temperature into a region of lower pressure. 2. A flow condition in which vapor pockets formed inside a valve persist downstream of the valve because the valve outlet pressure is at or below the fluid vapor pressure. [lSARP75.23-1995] flashlamp A gas-filled lamp that emits a short, bright flash of light when it is excited by an electrical pulse passing through it. A broad range of wavelengths are produced,
and their precise nature depends on the gas or gases used. flash line A raised line on the surface of a molded or die cast part that corresponds to the parting line between mold faces. flash memory One of the first applications of PCMCIA cards. A Type I card (see PCMCIA) that contains up to 20 MB RAM and a small battery so memory is retained when unplugged. Flash me.mory is an alternative to floppy disks and much faster than either .floppy or hard disks. flashover A disruptive:discharge in the form of arc or spark between two electrical conductors or between conductor and earth (ground). . flash plating - The electrodeposition of a very thin film of metal, usually just barely enough to completely cover the surface. flash point. T.he minimum temperature at which a liquid giv~s off vapor in sufficient concentration to form an ignitable mixture with the air near the surface of the liquid, as specified by a test. Note: For additional information, refer to NFPA 325. [ANSI/ISA12.01.01-1999] flatbed scanner A "device that scans images much as photocopy machines do; the original art or document is positioned face down on glass plate. flattening Straightening a metal sheet by passing it through a set of staggered and opposing rollers. These rollers bend the sheet slightly to flatten it, without reducing its thickness. flattening test A test that evaluates the ductility, formability, and weld quality of metal tubing by flattening it between parallel plates to a specified height. flatting agent A chemical additive that promotes a nonglossy, matte finish in paints and varnishes. flat tuning Tuning that has substantially equal response to the range of frequencies. flaw A discontinuity or other physical attribute in a material that exceeds acceptable limits. Since the term flaw is nonspecific, more specific terms such as defect, discontinuity, or imperfection are often preferred. flexible coupling A device that connects the shafts of the driver and driven machines and is at the same time capable of being bent and strong enough to transfer the power. Semiflexible coupling is a better term. flexible function block Similar to a standard function block, except that the function of the block, the order and definition of the block parameters, and the time required to execute
207