Glossary of Karst and Cave Terms
Based on "A Lexicon of Cave and Karst Terminology with Special to Environmental Karst Hydrology" EPA/600/R-02/003, 2002, EPA: Washington, DC., Speleogenesis Glossary includes 2699 cave & karst terms
Used to describe standard sizes for pipe from 1/8 inch to 12 inches (3.2 mm to 304 mm.) The nominal size is specified on the basis of the inside diameter. Depending on the wall thickness, the inside diameter may be less than or greater than the number indicated .