Expandable Pipe Coupling Seal for Low-Force Leak Tightness
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Solution Overview
Problem
Existing coupling elements for connecting and sealing pipes require significant force to overcome frictional forces, making the process cumbersome and potentially inefficient, especially in applications like buried stoneware pipes where leakage prevention is critical.
Innovation Solution
A coupling element featuring a cylindrical collar with a peripheral, expandable seal that transitions from an assembled to a sealing state by applying an expansion force, allowing the seal to be easily pushed over one pipe end and then pressed against the other, enhancing the sealing effect without excessive force application.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a cylindrical sleeve is pushed over pipe ends to create a seal, then sealing effect is improved, but considerable force must be applied due to frictional forces
Solution Approach 1:
The seal transitions from a non-expanded assembly state to an expanded sealing state during the coupling process. In the assembly state, the seal has a smaller diameter allowing easy insertion. Once positioned, the seal is expanded radially to increase its diameter and create a tight sealing contact with the pipe outer surface, transforming the static seal into a dynamic, state-changing component that resolves the force-friction contradiction.
Solution Approach 2:
The radial distance between the outer and inner surfaces of the seal is changed from a smaller value in the assembly state to a larger value in the sealing state. This parameter change allows the seal to transition from a state permitting easy insertion to a state providing strong sealing contact, thereby reducing the force required for coupling while maintaining reliable sealing.
2Reliability
If the seal is expanded radially to improve sealing, then sealing efficiency is improved, but the structure becomes more complex
Solution Approach 1:
The expandable seal is nested within the cylindrical sleeve, with the seal's outer surface supported by the sleeve's inner surface. This nested arrangement allows the seal to be contained within the sleeve structure during assembly and transport, then expanded radially when needed, achieving improved sealing efficiency without significantly increasing overall device complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Simplifies the coupling process and improves the sealing efficiency by allowing the seal to expand radially, ensuring a secure connection and minimizing leakage, particularly beneficial for buried pipes transporting liquids or gases.
Implementation Method 1
The expandable seal can be transitioned from an assembly state in which the seal is not expanded to a sealing state in which the seal is expanded. During the transition from the assembly state to the sealing state, the radial distance Δd between the outer and inner surfaces of the seal is increased by applying an expansion force acting through the inner surface of the seal.
Implementation Method 2
The fluid medium, which could be a liquid or a gas, can be forced into the cavity. By forcing the medium into the cavity, the fluid medium pushes the inner surface of the seal inwards, thus expanding the seal.
Implementation Method 3
The expandable medium could be an expanding foam that expands within the cavity. The expandable medium can also be a compressed band made of a foam material that expands by relaxing in the hollow chamber, thus generating the expansion force.
Implementation Method 4
The expansion force can be generated by activating a spring within the cavity, which presses the inner surface of the seal inwards. The spring could, for example, be a coil spring whose outer legs are fixed to the cuff. By releasing the legs from the cuff, the pre-tensioned spring is released and can relax, thereby pressing the inner surface of the seal inwards.
Data Source
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AI summary
Coupling element (20) for sealingly coupling two adjacent pipes (12, 14), comprising a cylindrical sleeve (22) with a cylindrical inner sleeve surface (24) and a circumferential expandable seal (34) arranged on the inner sleeve surface (24), which has a sealing outer surface (38) adjacent to the inner sleeve surfaces (24) and a sealing inner surface (36) designed to abut one of the pipes (12, 14), wherein the seal (34) is designed such that the distance Δd in the radial direction between the sealing outer surface (38) and the sealing inner surface (36) can be increased from an assembly state to a sealing state by applying an expansion force acting on the sealing inner surface (36), while the sealing outer surface (38) is supported by the inner sleeve surface (24),to press the inner sealing surface (36) against the outer pipe shell surface (40) of a first pipe (12) in the sealing state and to slide it over the first pipe (12) in the assembly state.