Pumping Station

Sump The sump is perhaps the most important element in the structure of the pumping station. Unless it is properly located, designed, and sized, the flow conditions within could have an adverse effect on the operation of the pump. There are many variations in sump arrangements that are acceptable; however, best results are obtained when the sumps or sump bays are oriented parallel to the line of flow. Flows approaching from an angle create dead spots and high local velocities, which result in the formation of vortices, nonuniform entrance velocities, and an increase in entrance losses. The flow to any pump should not be required to pass another pump before reaching the pump it is meant for. When sumps or sump bays are normal to the direction of flow, such as in sewer systems, the distance between the sump or sump bay entrance and the pump must be sufficient for the flow to straighten itself out before reaching the pump. For additional information relative to sump design and sizing, refer to Chapter 10. If the installation is large enough to warrant it, modeling of the sump to permit the best design to be determined is advocated.

Sumps in drainage installations pumping storm water should be either located above normal water levels, in which case they would be self-draining, or isolated from normal flows by gates. In small installations, motorized pressure-seating gates should be used; in large installations, roller gates raised and lowered with a crane or by some other suitable system should be used. These gates should be sized so the velocity through them will not exceed 5 ft/s (1.5 m/s) for any condition of flow. One gate should be located directly opposite each pump when all pumps are installed in a common sump or should be located at the entrance to each sump bay when pumps are separated.

Frequent cycling of pumps is encountered in installations that pump from sewer systems and that pump seepage. In such installations, the sump should be sized so the volume stored in it and in the ponding area or the sewer lines, as the case may be, within the limits of the operating range, will be sufficient to prevent the starting of the pumps more often than once every four minutes.

Superstructure A superstructure is provided on practically all drainage pumping stations but not on all irrigation pumping stations. The type of superstructure provided should be consistent with the surrounding area and should have a minimum number of windows and openings. In rural areas, corrugated sheet metal structures, which are inexpensive, have been used extensively. These provide adequate protection from the elements and from vandalism. To eliminate the need for an indoor crane, hatches in the roof over each pump can be provided to permit a truck crane to remove motors and pumps as a unit. For engine-driven pumps and larger pump installations, indoor cranes of the appropriate size and type should be provided for installation, removal, and maintenance.

Corrosion The corrosion of electrical and mechanical equipment in housed and unhoused stations can be controlled by painting exterior surfaces with a good paint and by installing strip heaters in all electrical enclosures. In large housed installations, heating of the operating room area in addition to the use of strip heaters should be considered. All equipment below the operating room floor level should be coated with a paint that is suitable for the exposure. In dry sump stations, enamels should be satisfactory. In wet sumps that are kept dry during inoperative periods, cold-applied coal tar enamel, which is easily repaired, is preferred. In installations where the equipment is continuously immersed, coal tar epoxy paint or vinyl paint should be used. If the water is extremely corrosive, consideration should be given to mounting galvanic anodes on the pumps in addition to painting.

End of Days Apocalypse

End of Days Apocalypse

This work on 2012 will attempt to note them allfrom the concepts andinvolvement by the authors of the Bible and its interpreters and theprophecies depicted in both the Hopi petroglyphs and the Mayan calendarto the prophetic uttering of such psychics, mediums, and prophets asNostradamus, Madame Blavatsky, Edgar Cayce, and Jean Dixon.

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