Glossary of Compressed Air Terms :: W :: Glossary Index A B C D E F G H I J K L M N O P Q R S T U V W X Y Z Warn The control ring in a valve which surrounds the seat, used to control pre open and blow down. Water cooled compressors Machines cooled by water circulated through jackets surrounding the cylinders or casings. Wet bulb temperature Is used in psychrometry and is the temperature recorded by a thermometer whose bulb has been covered with a wetted wick and whirled on a sling psychrometer. Taken with the dry bulb, it permits determination of relative humidity of the atmosphere. Wet gas Is any gas or gas mixture in which one or more of the constituents is at its saturated vapor pressure. The constituent at saturation pressure may or may not be water vapor. Wet helical lobe unit Is one which 1) handles a small constant flow of liquid with the gas; 2) utilizes evaporative (injection) cooling; or 3) circulates a liquid for sealing and/or cooling. The last may or may not be evaporative cooling. Wicking The vertical absorption of a liquid into a porous material by capillary forces. Winch An air operated device for hoisting or pulling. Similar to a slusher or tugger WMW Welded Minimum Wall tubing WOG WOG - A pressure rating in psi for valves. W. Water, O. Oil, G. Gas Work Is energy in transition and is defined in units of Force times Distance. Work cannot be done unless there is movement. Working pressure The normal working pressure for an air motor (6 bar). Glossary Index A B C D E F G H I J K L M N O P Q R S T U V W X Y Z