Abstract: To increase performance levels of pressurized water pumps, a hydrostatic joint arrangement (pressure seal) permits a controlled flow to occur between two chambers containing the same fluid placed under different pressures. This arrangement includes a metal bearing (3) attached to a rotary movable shaft (4) and a float (5) which is capable of unrestricted axial movement, whereby minimum flow of fluid between the bearing and the float can produce sufficient force for gradually raising the float (5), while maintaining a pressure seal. The bottom portion (7) of the float (5) contains openings (8) which are connected to a source of pressurized fluid by means of intake ducts (9), thereby to provide fluid flow between the bearing and the float regardless of the pressure difference between the two chambers.

Abstract: The safety device insures the longitudinal tightness of a pump shaft in the case where the pump dynamic gasket separating the high pressure chamber from the low pressure chamber of the pump brakes. According to the invention, the device comprises a cylindrical hollow piston coaxially surrounding the pump shaft and the structure allowing the axial displacement of the piston in order to compress a toroidal safety gasket between the shaft and the piston in the event of a failure of the dynamic gasket.