Conduit Joining Nut Geometry for Strike Wear and Fatigue Resistance
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Solution Overview
Problem
Nuts used in pumping operations, such as those in hydraulic fracking and concrete pouring, have a limited service life due to deformation from repeated striking and fatigue failures under high cyclic pressure loading, leading to inefficiencies and increased maintenance costs.
Innovation Solution
A nut design featuring a cylindrical body with a central opening, angled lugs for enhanced torque application, and a tapered surface to reduce internal stresses, along with ribs for increased strength and resilience, is developed to improve durability and efficiency in high-pressure applications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If traditional nuts are used with standard lug design, then torque can be applied for tightening, but the lugs become deformed from repeated striking during installation
Solution Approach 1:
The patent applies local quality by creating a strike surface on the lug that is specifically designed to be more durable than other portions of the nut. The strike surface is formed with a different geometry (angled relative to the lug axis) that provides enhanced resistance to deformation from hammer strikes, while other portions of the nut maintain their traditional design for threading and fluid flow.
2Productivity
If nuts are subjected to high cyclic pressure loading, then pumping operations can be performed, but fatigue failures occur
Solution Approach 1:
The patent applies parameter changes by modifying the geometric parameters of the nut, specifically the angle of the strike surface relative to the lug axis. This geometric parameter change creates a more favorable stress distribution pattern that reduces stress concentration points, thereby improving resistance to fatigue failure under cyclic pressure loading while maintaining pumping capability.
3Adaptability or versatility
If pipe segments are subject to bending loads, then installation flexibility is improved, but cracks develop in the nuts
Solution Approach 1:
The patent applies local quality by creating a specifically engineered strike surface on the lug that provides enhanced structural integrity at the critical stress point. This localized feature with a specific angle relative to the lug axis provides improved crack resistance under bending loads while maintaining the overall nut design for installation flexibility.
Data Source
AI summary
A nut for joining conduits includes a body having a generally cylindrical shape and defining a central opening. A plurality of lugs can extend outwardly from an outer surface of the body and provide one or more strike surfaces. The central opening can include a threaded portion proximate a first end of the nut and a tapered portion extending from the threaded portion. The tapered portion defines a frustoconical surface that expands the central opening beyond the threaded portion. The tapered portion may terminate at an undercut or flange proximate the second end of the nut.