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, preventing radial deformation and bulging, while elevated protrusions apply non-uniform pressure to enhance friction and maintain seal alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
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, reducing seal integrity
Solution Approach 1:
The restrainer acts as an intermediary element between the fastening lug and the seal. It mediates the tightening force by providing a bearing surface that prevents the fastening lug from directly contacting and pinching the seal, thus allowing the coupling to be tightened securely without compromising seal integrity
Solution Approach 2:
The restrainer is pre-positioned on the inner surface of the coupling segment before tightening occurs. This preliminary placement ensures that when the fastening lugs are drawn together, the restrainers are already in position to prevent seal trapping, eliminating the need for complex adjustment during the tightening process
2Strength
If the fastening lugs are drawn together to tighten the coupling, then the coupling strength is improved, but gaps between segments allow seal bulging and trapping
Solution Approach 1:
The restrainer serves as a mediator that fills and controls the gap between coupling segments. By providing a structured bearing surface within the gap, it prevents the seal from bulging into the gap and being trapped by the fastening lugs, while still allowing the lugs to draw the segments together tightly
3Reliability
If uniform compression is applied to the seal, then seal integrity is maintained, but alignment control during tightening becomes difficult
Solution Approach 1:
The restrainer introduces localized structural features at specific positions on the inner surface of the coupling segment. These localized features provide reference surfaces that guide seal alignment during installation and tightening, making alignment control easier without compromising the uniform compression needed for seal integrity
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 pinching and trapping, ensuring uniform compression and extending the seal's lifespan by maintaining its integrity during tightening and operation.
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
elevated protrusions apply non-uniform pressure to enhance friction and maintain seal alignment
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.