Fluid End Bore Sealing Without Internal Retaining Threads
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Solution Overview
Problem
Fluid end assemblies in oil and gas operations face issues with retaining nuts backing off due to high pressure, leading to fluid leakage and internal thread failures, which require frequent repair or replacement.
Innovation Solution
The design eliminates internal threads in the bores by using a retainer element and fastening system with externally threaded studs and washers to secure components within the fluid end body, preventing longitudinal movement and fluid leakage without forming external or internal threads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If retaining nuts are threaded into internal threads in bore walls to secure components, then components are held in place, but the internal threads are prone to failure and cracking under high pressure
Solution Approach 1:
The invention removes the internal threads from the bore walls entirely, extracting the problematic threaded connection system. Instead, it uses a retainer element with external threads that engages with the component without requiring internal threading of the bore, thereby eliminating the source of thread failures and cracking under high pressure.
Solution Approach 2:
The invention inverts the threading approach by using external threads on the retainer element instead of internal threads in the bore wall. The retainer element's external threads engage with corresponding features on the component, reversing the traditional internal threading configuration and eliminating the weakness of internal threaded connections under high pressure.
2Stability of the object's composition
If retaining nuts are used to secure components in bores, then components are retained, but the nuts can back off due to high pressure causing fluid leakage
Solution Approach 1:
The retainer element serves as an intermediary component between the bore wall and the component. It provides a stable retaining mechanism through external threading and engagement features that prevent back-off under high pressure, while also maintaining proper component positioning and seal integrity without the reliability issues of traditional retaining nuts.
3Ease of manufacture
If internal threads are formed in bore walls for retaining nuts, then components can be secured, but repair or replacement is required when threads fail
Solution Approach 1:
By removing the internal threads from the bore wall design, the invention eliminates the need for complex repair operations when thread failure occurs. The retainer element with external threads can be independently replaced without affecting the bore wall structure, significantly simplifying maintenance and repair procedures.
4Ease of operation
If traditional retaining nuts are used in fluid end assemblies, then components are held secure, but frequent failure requires frequent repair or replacement
Solution Approach 1:
The retainer element is designed as a replaceable component that can be independently serviced. When wear or damage occurs, the retainer element itself can be replaced without replacing the entire fluid end assembly, effectively creating a disposable or short-service-life component that protects the more expensive main assembly and maintains productivity.
Data Source
AI summary
A fluid end having its fluid flow bores sealed without threading a retaining nut into the walls of each bore. The fluid ends may be assembled using a plurality of different kits that each comprise a fluid end body, a component, a retainer element, and a fastening system. The retainer element holds the component within each of the bores formed in the fluid end body and the fastening system secures the retainer element to the body. The fastening system comprises a plurality of externally threaded studs, washers and nuts in some embodiments. In other embodiments, the fastening system comprises a plurality of screws.