The Bladder-type Air/Water Pressure Cylinder is an interface which exchange pneumatic pressure (regulated compressed Air) into hydraulic pressure and delivers hydrostatic pressure to Triaxial/Permeability cells.It also works as a safety reservoir between Pneumatic pressure controller (APC) and Triaxial cell and prevent the water reintroduction from Triaxial cell into pneumatic pressure during test.

It generates continuously water supply under defined pressures (usually the cell pressure dominating in the test cell) up to 1600 kPa for Triaxial cells or permeability tests under isotropic or anisotropic static loads.It is constructed of stainless-steel top and bot-tom plates, Plexiglass cylinder and a rubber membrane as bladder.