Non-Circular Closure Element for Reciprocating Pump Fluid Ends
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Solution Overview
Problem
High pressure reciprocating pumps face issues with leakage and wear due to traditional threaded connections in sealing assemblies, which are prone to fatigue and invasive repairs, especially in harsh drilling operations.
Innovation Solution
A closure element with a non-circular cross-sectional shape that can be self-retaining and installed without threading, featuring a seating section and closure section with distinct shapes to facilitate sealing and retention within a fluid end, allowing for corner seals and easy replacement of sealing areas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional threaded connections are used to secure retaining elements in sealing assemblies, then the sealing assembly can be securely retained, but the threaded connections are prone to fatigue failure and require invasive repairs
Solution Approach 1:
The patent removes the threaded connection component entirely from the sealing assembly. Instead of using a retaining element with threads that engage threaded bores, the invention uses a closure element with a non-circular cross-section that directly fits into a corresponding non-circular bore, eliminating the need for threaded connections and their associated fatigue and repair issues.
Solution Approach 2:
The patent employs asymmetric (non-circular) geometry for both the closure element and the bore. The closure element has a non-circular cross-section that matches the non-circular bore shape, creating a form-fit connection that eliminates the need for threading while providing secure retention through geometric compatibility rather than threaded engagement.
2Strength
If threaded retaining elements are used to secure closure elements, then the closure can be firmly attached, but the threads experience high cyclical stress leading to fatigue failure
Solution Approach 1:
The invention extracts and eliminates the threaded connection system from the design. By using a non-circular closure element that fits into a corresponding non-circular bore, the design removes the threads that are subject to high cyclical stress and fatigue failure, while maintaining secure attachment through geometric interlocking.
Solution Approach 2:
The asymmetric non-circular geometry of the closure element and bore creates a connection that distributes stress more evenly without the stress concentration points inherent in threaded connections. The form-fit connection provided by the non-circular shapes provides firm attachment while avoiding the fatigue-prone threaded interface.
3Reliability
If sealing areas are located at traditional radial seal positions, then the sealing function is achieved, but the sealing areas are subject to wear and damage over time
Solution Approach 1:
The non-circular closure element enables the sealing area to be positioned at a corner or offset location rather than at a traditional radial seal position. This asymmetric sealing arrangement, made possible by the non-circular geometry, moves the sealing interface away from high-wear radial locations to areas that experience less wear and damage during pump operation.
Data Source
AI summary
A closure element for a fluid end of a reciprocating pump is installable within a segment of a casing of the fluid end to substantially close the segment. The closure element includes a main body that extends from an interior surface to an exterior surface, and at least a portion of the main body has a non-circular cross-sectional shape. A fluid end of the closure element may include a plurality of segments and at least a portion of at least one segment of the plurality of segments may have a non-circular cross-sectional shape configured to receive and secure a closure element with a non-circular cross-sectional shape.