Abstract: A pump system includes dual centrifugal pumps mounted on a fabricated skid. Both pumps are belt driven by one motor. The pumps are piped with three two-way valves and crossover piping configured such that the pumps can be operated in either series or parallel flow using a single inlet and outlet for the system.

Abstract: A centrifugal pump including a pump chamber, a wear plate, and a rotatable impeller is disclosed. The wear plate has a suction inlet. The pump chamber includes a high pressure region around the impeller within the pump chamber. The impeller's front face has portion located adjacent the wear plate to form a recirculation zone in fluid communication with the high pressure region. Another portion of the impeller's front face forms a small running clearance between it and a portion of the wear plate. That running clearance is interposed between the recirculation zone and the suction inlet. The wear plate includes plural deflector vanes projecting into the recirculation zone. A portion of the front face of the impeller includes plural pump-out vanes in the recirculation zone. The deflector vanes cooperate with the pump-out vanes to expel abrasive particles and prevent them from collecting and eroding the running clearance.

Abstract: A centrifugal pump with a cutter mechanism has a toothed cutter auger affixed to an impeller, and a toothed cutter stator affixed to the volute casing. The auger is a rotor cutter preferably profiled radially to match the inlet geometry of the impeller vanes while extending along its central axis towards the pump suction. The auger is preferably radially concentric to the impeller and includes vanes numbered preferably to match the number of vanes on the impeller. The auger is affixed to the impeller, preferably with a lockscrew threaded into a common pump shaft. The radial profile of the auger essentially makes a continuous vane with the impeller, and prevents solids from hanging on the inlet vane tip or center void while providing a smooth flow transition into the impeller.

Abstract: A convertible check valve having a pair of valve body sections, each of which includes a central passageway extending through it is disclosed. Each passageway terminates at an elliptical port. A moveable flapper is located within the check valve between the valve body sections and is movable between a between a closed state and an opened state, and vice versa, to effect the selective closing and opening of the ports. The valve body sections are configured to be rotated 180 degrees with respect to each other so that they are in an either an axially aligned state or in an elbow state. The interface between the passageways is formed by two elliptical shaped planar surfaces, each extending at an angle of 45 degrees to the central axis of the associated passageway. The valve also includes a pressure relief assembly.

Abstract: A centrifugal pump with a cutter mechanism has a toothed cutter auger affixed to an impeller, and a toothed cutter stator affixed to the volute casing. The auger is a rotor cutter preferably profiled radially to match the inlet geometry of the impeller vanes while extending along its central axis towards the pump suction. The auger is preferably radially concentric to the impeller and includes vanes numbered preferably to match the number of vanes on the impeller. The auger is affixed to the impeller, preferably with a lockscrew threaded into a common pump shaft. The radial profile of the auger essentially makes a continuous vane with the impeller, and prevents solids from hanging on the inlet vane tip or center void while providing a smooth flow transition into the impeller.

Abstract: A centrifugal pump with a cutter mechanism consisting of a toothed cutter rotor, integral with the impeller wear ring, affixed to the impeller and a toothed cutter stator affixed to the casing, separately from the casing wear ring. A cutter mechanism consisting of a stator and rotor set such that they may be installed on the centrifugal pump impeller and casing as original equipment or as a retrofit. A cutter mechanism such that when installed in a centrifugal pump they prevent stringy materials, garbage and other agglomerated soft wastewater solids from partially restricting or totally blocking the inlet to the pump impeller. A cutter mechanism such that when it prevents solids from restricting or blocking the impeller inlet, it does so without significant decrease of flow throughput or significant increase in absorbed hydraulic horsepower.

Abstract: A labyrinth seal for sealing an impeller shaft within a pump housing. The seal includes inner and outer coaxial, relatively rotatable members secured to the shaft and the housing, respectively. Defined between the two members is a succession of axially extending sleeve-shaped passages of decreasing diameters progressing toward the pump interior, these passages being connected by radially extending disc-shaped passages. Fluid moving through the sleeve-shaped and disc-shaped passages flows into annular grooves formed at the ends of these passages, setting up currents which resist fluid flow through the seal.