vacuum check
31Backflow prevention device — See also: Backflow (plumbing) In this situation, dirty water from the hillside pool will back siphon or back flow down the hosepipe and into the clean water tank. To prevent this from happening, the house s external tap should be fitted with a… …
32Spain — /spayn/, n. a kingdom in SW Europe. Including the Balearic and Canary islands, 39,244,195; 194,988 sq. mi. (505,019 sq. km). Cap.: Madrid. Spanish, España. * * * Spain Introduction Spain Background: Spain s powerful world empire of the 16th and… …
33Water hammer — (or, more generally, fluid hammer) is a pressure surge or wave resulting when a fluid in motion is forced to stop or change direction suddenly (Momentum Change). Water hammer commonly occurs when a valve is closed suddenly at an end of a pipeline …
34Chemigation valve — A chemigation valve is an apparatus designed to protect water supplies from agricultural chemicals used during chemigation, the application of chemicals such as fertilizers and pesticides through irrigation water. Most chemigation valves consist… …
35international relations — a branch of political science dealing with the relations between nations. [1970 75] * * * Study of the relations of states with each other and with international organizations and certain subnational entities (e.g., bureaucracies and political… …
36Europe, history of — Introduction history of European peoples and cultures from prehistoric times to the present. Europe is a more ambiguous term than most geographic expressions. Its etymology is doubtful, as is the physical extent of the area it designates.… …
37Space accidents and incidents — Space accidents, either during operations or training for spaceflights, have killed 22 astronauts (five percent of all people who have been in space, two percent of individual spaceflights), and a much larger number of ground crew. This article… …
38Milking pipeline — A milking pipeline or milk pipeline is a component of a dairy farm animal milking operation, which is used to transfer milk from the animals to a cooling and storage bulk tank. Contents 1 Setup 2 Transfer from pipeline to bulk tank 3 Pipeline… …
39gasoline engine — Most widely used form of internal combustion engine, found in most automobiles and many other vehicles. Gasoline engines vary significantly in size, weight per unit of power generated, and arrangement of components. The principal type is the… …
40Automobile accessory power — can be produced by several different means. However, it is always ultimately derived from the automobile s internal combustion engine. An engine has one or more devices for converting energy it produces into a usable form, electricity connection… …
