High-pressure seal with controlled deflection under pressure
AssigneeFlow Industries, Inc.
InventorsJohn H. Olsen, Robert S. Pritchard
Life of this patent
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Abstract
A seal for a movable shaft which extends from a cavity within a high-pressure vessel maintains a uniform gap between the shaft and the seal body at high pressures to form an effective seal while providing adequate clearance between the shaft and the seal body to prevent excessive wear.
Claims21
A seal for a shaft extending between high pressure and low pressure regions, comprising:
- a seal body for surrounding said shaft with a gap of predetermined configuration between said seal body and said shaft under non-pressurized conditions and extending from said high pressure region to said low pressure region, the exterior of said seal body being subjected to the fluid pressure within said high pressure region acting radially thereon;
- and means for controlling the radial compressive deformation of said seal body along the length thereof to provide a predetermined clearance between said seal body and said shaft under pressurized conditions to control leakage of said high-pressure fluid.
A seal for controlling leakage about a shaft which extends from a high pressure region to a low pressure region, comprising:
- a seal body which is compressible by the high pressure in the high fluid pressure region, said seal body having an exterior sidewall exposed to the fluid pressure in said high fluid pressure region, and a passage there through, said passage extending from the high fluid pressure region to the low fluid pressure region for admitting the shaft there through for providing a predetermined clearance between said passage and the shaft under pressurized conditions.
A seal for a shaft extending through an orifice in a wall of a high pressure vessel to a low pressure region, comprising:
- a sealing surface around said orifice;
- and
- a sealing body surrounding said shaft with a gap of predetermined configuration therebetween under non-pressurized conditions and extending from the interior of said high pressure vessel to said low pressure region, said seal body having a compression sealing area engaged with said sealing surface under pressurized conditions, the fluid pressure within said high pressure vessel exerting radial and axial compressive forces on said seal body, said axial compressive force acting on an area of said seal body within said high pressure vessel greater than said compression sealing area to form a sealing pressure between said compression sealing area and said sealing surface, said sealing pressure being greater than the pressure within said high pressure vessel, said radial compressive force radially deforming said seal body to provide a predetermined clearance between said seal body and said shaft along the length of said gap.
A method for sealing an operating shaft extending between high pressure and low pressure regions comprising the steps of:
- surrounding said shaft with a deformable seal body having a predetermined gap between said shaft and said seal body;
- subjecting the exterior of said seal body to high pressure whereby said seal body is radially compressed about said shaft;
- and
- controlling the resistance to compressive deformation of said seal body to provide a predetermined clearance between said seal body and said shaft at operating pressure.
Dependencies are inferred from the claim text.