Abstract: A multi-stage submersible pump uses impellers having only one shroud to provide stages with shorter stack lengths to allow more stages per housing and more head pressure per housing. The impellers are biased with wave springs to keep the rotating impeller vanes close to the mating diffusers. The entire stack of impellers is assembled in contact with each other using the wave springs and are always under axial load. The wave springs also take up any tolerance variations in the stack to keep the impellers in proper running position. To keep the impellers in their proper locations, thrust washers formed from hard materials are used between adjacent impellers to avoid erosion thereof.

Abstract: A stackable multi-stage diffuser with anti-rotation lugs utilizes cast lugs and complementary recesses in the diffuser walls. When stacked in a housing, the lugs of lower diffusers nest inside the recesses of upper diffusers. The diffuser sections interlock and are mechanically locked in the housing to prevent rotation of the diffusers. Each diffuser is sealed directly to adjacent diffusers with o-rings, but do not contact or seal to the housing.

Abstract: An electrical submersible pump assembly (ESP) includes a pump section, a motor section, and a seal section. In one embodiment, an exterior of the pump section defines a gripping indentation above the pump intake. Alternatively, a clamp member may be provided that surrounds the pump, wherein the clamp member defines the gripping indentation. A collet adapter is affixed to an upper end of a shroud. The collet adapter has gripping members that engage the gripping indentation for attaching the shroud to the electrical submersible pump assembly. The collet adapter is provided to ease installation of the motor shroud onto the ESP as well as to ease removal of the motor shroud from the ESP. The collet adapter of the present invention eliminates precise alignment and bolt-on requirements of typical motor shroud mounting techniques.

Abstract: A multi-stage submersible pump uses impellers having only one shroud to provide stages with shorter stack lengths to allow more stages per housing and more head pressure per housing. The impellers are biased with wave springs to keep the rotating impeller vanes close to the mating diffusers. The entire stack of impellers is assembled in contact with each other using the wave springs and are always under axial load. The wave springs also take up any tolerance variations in the stack to keep the impellers in proper running position. To keep the impellers in their proper locations, thrust washers formed from hard materials are used between adjacent impellers to avoid erosion thereof.

Abstract: An electrical submersible pump assembly (ESP) includes a pump section, a motor section, and a seal section. In one embodiment, an exterior of the pump section defines a gripping indentation above the pump intake. Alternatively, a clamp member may be provided that surrounds the pump, wherein the clamp member defines the gripping indentation. A collet adapter is affixed to an upper end of a shroud. The collet adapter has gripping members that engage the gripping indentation for attaching the shroud to the electrical submersible pump assembly. The collet adapter is provided to ease installation of the motor shroud onto the ESP as well as to ease removal of the motor shroud from the ESP. The collet adapter of the present invention eliminates precise alignment and bolt-on requirements of typical motor shroud mounting techniques.

Abstract: A stackable multi-stage diffuser with anti-rotation lugs utilizes cast lugs and complementary recesses in the diffuser walls. When stacked in a housing, the lugs of lower diffusers nest inside the recesses of upper diffusers. The diffuser sections interlock and are mechanically locked in the housing to prevent rotation of the diffusers. Each diffuser is sealed directly to adjacent diffusers with o-rings, but do not contact or seal to the housing.

Abstract: The scanning and processing of a multi-page document is described wherein scan images are generated by optically scanning a sequence of pages of a multi-page document such as a book, processing the scan images to generate page images corresponding to original pages of the multi-page document, e.g., by deskewing and removing black border areas, and after generating a proposed page image, it is checked to determine if there is a chance that the image contains errors, by detecting if its image parameters, such as the text area coordinates (X1, X2, X3, X4, Y1, Y2) are according to target criteria which are based on a statistical analysis of the document. If the page image satisfies the target criteria, the page image is automatically accepted, and if it does not, the page image is displayed to an operator to accept or to adjust the page image.