Abstract: A pump wherein the parts of the casing forming, together with the partitions and sealing members, chambers for the accommodation of impellers mounted in a counteropposed manner on a shaft, are interconnected in the plane perpendicular to the rotation axis of the impellers by a clamp. The clamp consists of two parts with the joining plane passing through the rotation axis of the impellers and the clamp has circular collars at the edges, the collars entering circular recesses provided in flanges located on the opposite sides of the casing parts. The clamp is adapted for compressing the sealing members while the clamp parts are being brought together.

Abstract: A pump for handling liquids laden with abrasive particles in which the seal of the shaft between the low- and high-pressure stages comprises at least two floating rings provided on the shaft in a circular gap between the shaft and the casing. The casing has a circular collar at the side of the low-pressure stage, partly covering the circular gap which is adjoined by the rings during pump operation.

Abstract: A pump for handling liquids laden with abrasive particles having impellers arranged in a counter-opposed manner on the pump shaft to rotate jointly with the latter. At the points of impeller mounting, the shaft has tapered surfaces whose apices face each other and the mating surfaces of the impellers are also tapered. At least one of the tapered surfaces of the shaft is formed by a bushing disposed with provision for moving axially along said shaft for pressing the impellers against the corresponding tapered surfaces of the shaft. This mode of mounting the impellers extends considerably the service life of the pump.