APPENDIX  I GLOSSARY ABRASION—  Wearing away of a surface by friction, either by motion while in contact with another part, or by mechanical cleaning or resurfacing with abra- sive  cloth  or  compound. ADDITIVES—  Chemicals added in minor proportions to fuels or lubricants to create, enhance, or inhibit selected  properties;  for  example,  fuel  system  icing inhibitor  (FSII). ADHESIVE—  Sticky or tenacious; glue. AMBIENT—  Encompassing on all sides, as tempera- ture. AMMETER— Electrical instrument for measuring the flow  of  current. ANODE—  The positively charged electrode of an elec- trolytic  cell. ANSI— Abbreviation for American National Standards Institute. ANTIFREEZE— A substance having a low freezing point, usually used to inhibit freezing of cooling system fluids in engines. API— Abbreviation  for  American  Petroleum  Institute. API  GRAVITY—  Petroleum  industry  scale  for  meas- uring the density of oils, adopted by the American Petroleum  Institute. ARC— A luminous, electrical discharge across a gap in a circuit or two electrodes, as in arc welding. ASTM— Abbreviation for the American Society for Testing  Materials. AUTOIGNITION  TEMPERATURE—  The tempera- ture at which a substance will ignite without further addition of energy (heat, spark, or flame) from an outside  source. AVGAS—  Common  term  for  aviation  gasoline. BALLAST—  Water, usually salt water, earned in cargo tanks when free of petroleum products to reduce buoyancy and improve stability and sea-keeping qualities. Ballast may be clean or dirty, depending on whether it is contaminated with petroleum prod- ucts. BARREL— Measure of volume as used in the petro- leum  industry,  equivalent  to  42  U.S.  gallons. BLACK OIL—  general term applied to crude oil and the heavier and the darker colored petroleum prod- ucts such as residual fuel oils. BONDING—  See  GROUND. BOOM— Flexible floating barrier consisting of linked segments designed to contain free oil on the surface of a body of water. BOOSTER PUMP—  Pump installed along the run of a long pipeline to increase (boost) the pressure. BOTTOM LOADING— Method of filling tank trucks or tank cars through a leakproof connection at the bottom. BREAKAWAY COUPLING—  Coupling  designed  to part easily with a moderate pull. BREATHING— The movement of vapors in and out of the vent lines of storage tanks because of natural heating  or  cooling. BS&W— Common  abbreviation  for  bottom  sediment and water; a test made on some heavier petroleum products to show the approximate amount of sedi- ment and water. Btu— Abbreviation for British thermal unit, a unit of heat commonly used in heat engineering. It is the amount of heat necessary to raise the temperature of 1 pound of water one degree Fahrenheit. BULK STORAGE TANK—  A fixed tank used to re- ceive, store, and issue fuel for further transporta- tion,  storage,  handling,  or  treatment  before  it reaches art operating tank. CALIBILITION—   Adjustment of the scale of a gradu- ated device (such as a pressure gage) to meet an established  standard. COz— Chemical notation for carbon dioxide, a heavy, colorless  gas  that  will  not  support  combustion.  It  is used for fighting small fires and in protection sys- tems in MOGAS and JP-5 spaces aboard ship. CATHODE—  The negatively charged electrode of an electrolytic  cell. AI-1