Sprinklers are designed to protect buildings by means of overhead pipes which convey an extinguishing fluid (such as water) to heat-activated outlets.
Today sprinklers incorporate a glass tube containing a special fluid and a small amount of air. If the temperature increases, the fluid expands in the glass tube. The pressure continues to increase until the air in the glass tube is absorbed. If the temperature continues to rise, the pressure increases rapidly, causing the glass tube to shatter and the seal to be broken. A shower of extinguishing water is then distributed evenly over the seat of the fire.
In many countries the use of sprinklers in certain buildings is mandatory, for example in high rise buildings and larger commercial buildings, aged care facilities, etc.
