Air-chamber

Ve el or reservoir so attached to a pump or to the pipe through which an incompre ible fluid is moving, as to imprison a volume of air. The shape is usually an inverted cone, or le often a cylinder. The imprisoned air acts as a spring or cushion to absorb and equalize the shocks due to the inertia or momentum of the fluid ma when the driving force acts irregularly or the column is arrested suddenly. The shock or "water-hammer" (q.v.) is absorbed by the air-spring of a chamber on the suction-pipe to a pump, when the water flows to the pump under a head. Such an air-chamber is often and improperly called a "vacuum chamber."