Abstract: Valve seat (1) for a valve for a piston pump, comprising a ring (2) with a flat side and a disc (4) with a flat side received within this ring (2), wherein the flat sides of the ring (2) and the disc (4) lie in one plane, and the ring (2) and the disc (4) are coupled by at least two arcuate arms (6) extending from the side remote from the flat side of the disc (4).

Abstract: Apparatus for drainage by well points, including a piston pump and a drive motor coupled to the piston pump by means of a transmission and provided with a drive shaft, which transmission is received in a housing and includes at least one crankshaft and a drive rod coupled thereto, the drive rod is coupled by means of a cross-head to a piston rod of the piston pump and the housing forms an oil sump and the transmission further includes an assembly of a worm and a worm wheel co-acting therewith and mounted on the crankshaft and the worm is provided on a worm shaft extending transversely relative to the crankshaft and vertically in operating mode of the apparatus for drainage by well points.

Abstract: Apparatus for drainage by well points, including a piston pump and a drive motor coupled to the piston pump by means of a transmission and provided with a drive shaft, which transmission is received in a housing and includes at least one crankshaft and a drive rod coupled thereto, the drive rod is coupled by means of a cross-head to a piston rod of the piston pump and the housing forms an oil sump and the transmission further includes an assembly of a worm and a worm wheel co-acting therewith and mounted on the crankshaft and the worm is provided on a worm shaft extending transversely relative to the crankshaft and vertically in operating mode of the apparatus for drainage by well points.