Abstract: A piston pump installation, and method of operation the same, for conveying sludge-type materials and granulated and solid materials with added fluid, comprising one or more, preferably two, cylinders arranged adjacent and parallel to one another with axially reciprocating pistons therein. Each cylinder having a valve provided at its front end, and a drive and control device located at the rear, opposite end. The valve located at the front of each cylinder is structured as a slide valve or so that it can turn and is connected to a suction main on one side and to a delivery pipe on the other side, the suction main and the delivery pipe preferably being perpendicular to the longitudinal axis of the cylinder. Each valve having a valve body with an inlet orifice and a cutting edge as well as an overlapping surface. The inlet orifice in the valve body being designed as a flow connection between the suction main and the cylinder as well as between the cylinder and the delivery pipe.

Abstract: A sludge press wherein a piston is reciprocable along a horizontal path between a rectracted position in the interior of a hopper and an extended position in which extending forwardly from and communicating with the hopper so that the piston thereby expels a slug of compacted sludge through the open front end of the barrel. The front end of the barrel can be sealed by the knife-like valve member of a gate valve during movement of the piston to retracted position. The front end face of the piston is surrounded by a cutting edge which cooperates with a complementary annular cutting edge at the rear end of the barrel to sever solid ingredients of sludge during penetration of the piston into the barrel. The cutting edge of the valve member cooperates with a complementary cutting edge surrounding an opening in the rear section of the housing of the valve.

Abstract: A sludge press wherein a piston is reciprocable along a horizontal path between a retracted position in the interior of a hopper and an extended position in which the piston is located in and at the front end of a barrel extending forwardly from and communicating with the hopper so that the piston thereby expels a slug of compacted sludge through the open front end of the barrel. The front end of the barrel can be sealed by the knife-like valve member of a gate valve during movement of the piston to retracted position. The front end face of the piston is surrounded by a cutting edge which cooperates with a complementary annular cutting edge at the rear end of the barrel to sever solid ingredients of sludge during penetration of the piston into the barrel. The cutting edge of the valve member cooperates with a complementary cutting edge surrounding an opening in the rear section of the housing of the valve.