Grooved Pipe Coupling Restrainers to Prevent Seal Pinching
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Solution Overview
Problem
Grooved pipe couplings often pinch and trap elastomeric seals during tightening, leading to non-uniform compression and reduced seal integrity, which compromises the sealed connection and shortens the seal's lifespan.
Innovation Solution
The pipe coupling assembly features coupling segments with restrainers that inhibit seal trapping by sliding against the seal's outer surface and closing gaps between segments, along with elevated protrusions that apply non-uniform pressure and guide the seal into place, preventing pinching and ensuring uniform compression.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the coupling segments are tightened to secure the pipe elements, then the sealing force is improved, but the seal is pinched and trapped between the fastening lugs leading to non-uniform compression
Solution Approach 1:
The restrainer acts as an intermediary element between the fastening lugs and the seal. It mediates the tightening force by distributing it uniformly across the seal while preventing direct pinching by the lugs. The restrainer translates the clamping action into uniform radial compression of the seal, resolving the contradiction between achieving sealing force and maintaining compression uniformity.
2Strength
If the fastening lugs are drawn together to tighten the coupling, then the coupling strength is improved, but gaps between segments cause seal trapping and deformation
Solution Approach 1:
The restrainer performs a preliminary action by establishing a continuous barrier before the fastening lugs are fully drawn together. It proactively prevents seal trapping by closing gaps between segments during the tightening process, ensuring seal integrity is maintained even as coupling strength increases through lug compression.
3Adaptability or versatility
If the seal is allowed to deform radially during tightening, then the seal adapts to the pipe surface, but the seal is pinched and trapped reducing its lifespan
Solution Approach 1:
The restrainer creates different local conditions for seal deformation: it allows controlled radial deformation where needed for adaptation to the pipe surface, while simultaneously preventing excessive deformation and trapping in critical areas. This localized control enables the seal to adapt appropriately without compromising its lifespan.
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
This design prevents seal trapping and deformation, maintaining the seal's integrity and extending its lifespan by ensuring uniform compression and proper alignment during the coupling process.
Implementation Method 1
The restrainer slides along an outer surface of the seal to physically block radial deformation (e.g., projection) of the seal
Implementation Method 2
The seal includes a resilient yet flexible elastomeric ring configured to engage the ends of the pipe element to provide, together with the coupling segments a fluid tight seal
Data Source
AI summary
A pipe coupling assembly (200) for use with a seal (16) for sealing end portions of pipe elements (34), including: first and second coupling segments (10), each including a curved portion (12) having an inner surface (14) shaped to define an annular channel and shaped and sized to receive the seal therein. A fastening lug member (18) extends from the curved portion, the fastening lugs of the first and second coupling segments at least partially overlap when the fastening lug members are drawn towards each other. At least one restrainer (30) extending from an end (58) of the fastening lug member and in continuation with the inner surface of the curved portion of at least one of the coupling segments, inhibits trapping of the seal between the fastening lug members when the fastening lug members are drawn toward each other. Other embodiments are also described.