摘要 |
A fluid pump having a pump body defining a pump cavity and a pump shaft rotatable on a bearing in the cavity, wherein the pump cavity contains a seal in a closed chamber between the pump body and the shaft, and the cavity is characterized by a first zone for high pressure pump discharge fluid, a second zone for low pressure pump inlet fluid, and an interconnecting passage which supplies fluid from the high pressure zone to a third zone, which exists at an intermediate pressure surrounding the pump seal and discharges its fluid into the low pressure zone, the intermediate pressure being sufficient to prevent fluid boiling and cavitation by insuring that the pumped fluid does not exceed its vapor pressure point.
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