Back-up mechanical seal
AssigneeBorg-Warner Corporation
InventorArnold F. Padgett
Life of this patent
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Abstract
A pump assembly having an impeller for pumping a fluid from an intake to an outlet, a prime mover for driving the impeller, and a primary mechanical seal assembly between the prime mover and the impeller which is located in a housing. The mechanical seal assembly substantially prevents leakage of the fluid being pumped along a shaft connecting the impeller and the prime mover. A secondary mechanical seal means is located in the housing between the prime mover and the mechanical seal assembly. The secondary seal means is constructed of a material, such as carbon, which will collapse under pressure of the fluid being pumped upon failure of the primary mechanical seal assembly, to substantially prevent the leakage of fluid along the shaft and to the exterior of the housing.
Claims10
In a pump assembly having a housing defining an inlet and an outlet, an impeller for pumping a fluid from the intake to the outlet, means including a shaft to drive the impeller, and a mechanical seal assembly located between the drive means and the impeller within the housing for substantially preventing the leakage of the fluid being pumped along the shaft, the improvement which comprises:
- a secondary mechanical seal means located between the mechanical seal assembly and said drive means and adjacent to the exterior of said housing, said secondary seal means comprising:
- a seal ring surrounding said shaft with a predetermined space therebetween;
- a non-rotatable support
- means to connect said seal ring to said support;
- and
- means biasing said support toward said seal ring;
- said seal ring being constructed of a material which will collapse under pressure of fluid being pumped upon failure of said mechanical seal assembly to seal said predetermined space between said seal ring and said shaft to substantially prevent leakage of fluid along said shaft and to the exterior of said housing.
A secondary mechanical seal means for a centrifugal pump to prevent the escape of pumping fluid along a rotatable pump shaft to the exterior of the pump housing in the event of failure of a primary mechanical seal means comprising:
- a seal ring constructed of segments of carbon surrounding and spaced from said shaft;
- means to hold said segments in assembled relationship around said shaft;
- and
- means to support said seal ring against rotation with said shaft;
- said carbon seal ring segments being so constructed and arranged to collapse under pressure of pumped fluid and to seal against said shaft upon failure of said primary mechanical seal means while permitting said shaft to rotate until shut-down of said pump.
Dependencies are inferred from the claim text.