External Fire Hydrant Installed On A Paved Footway With A Gray Wall Behind It. Royalty-Free Stock Photo

A fire hydrant, fireplug or "Johnny Pump" is a connection point by which firefighters can tap into a water supply. It is a component of active fire protection. Underground fire hydrants have been used in Europe and Asia since at least the 18th century. Above-ground pillar-type hydrants are a 19th-century invention. The user attaches a hose to the fire hydrant, then opens a valve on the hydrant to provide a powerful flow of water, the pressure varies according to region and depends on various factors (including the size and location of the attached water main). The external fire hydrant is a fixed device with a tap (valve) located outside the buildings and connected to the water distribution pipes under pressure, which allows the supply of fire trucks in case of fire.