Line Stop Flange Locking Mechanism Sealing

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional line stop assemblies suffer from leakage due to inadequate seals between components and performance degradation caused by improper alignment of locking mechanism components within the radial bore.

Innovation Solution

A line stop flange with a locking mechanism featuring a bushing and screw assembly that provides a metal-to-metal seal and self-alignment capabilities, ensuring effective sealing even with non-concentric alignment, using a bushing with a cavity and lip, and a screw with a circumferential channel and head, which maintains a consistent seal and alignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional sealing components are used in line stop assemblies, then the assembly can be manufactured and installed, but leakage occurs due to inadequate seal between components

Engineering Contradiction:
Improvesealing effectivenessVSAvoidleakage
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

A bushing is introduced as an intermediary component between the locking mechanism and the radial bore. The bushing includes a sealing surface that contacts the radial bore wall, and a cavity that receives the screw head. This intermediary bushing ensures proper sealing without requiring precise concentricity between the locking mechanism components and the radial bore, thereby preventing leakage while maintaining ease of assembly.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If locking mechanism components are disposed in a radial bore of the line stop assembly, then the locking function is provided, but performance degrades if the components are not properly aligned (not concentric to the radial bore)

Engineering Contradiction:
Improvelocking functionVSAvoidalignment concentricity
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The bushing serves as a mediator that decouples the alignment requirements. It has a outer surface that contacts the radial bore wall and an inner cavity that receives the screw head. This bushing absorbs any misalignment between the radial bore and the locking mechanism components, allowing the components to function properly even when not perfectly concentric, thus maintaining ease of operation while reducing manufacturing precision requirements.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The design changes the geometric parameters of the bushing, specifically providing a cavity with diameter larger than the screw head diameter. This parameter change allows the screw head to be received within the cavity without requiring precise concentric alignment, as the bushing can accommodate positional variations while maintaining the locking function.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If a bushing with cavity and lip is used to receive the screw head, then self-alignment is achieved and sealing is maintained, but the device complexity increases

Engineering Contradiction:
Improveseal consistencyVSAvoidnumber of components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The bushing combines multiple functions into a single component: it provides sealing against the radial bore wall through its outer surface, receives and positions the screw head through its cavity, and enables self-alignment of the locking mechanism. By merging these functions into one bushing component rather than using separate sealing elements and positioning features, the design achieves reliable sealing and self-alignment without proportionally increasing device complexity.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP2739893B1Line stop flange
Publication Date: 2018.01.24 DRESSER INC
  • EP2739893B1 patent drawingFigure 1
  • EP2739893B1 patent drawingFigure 2
  • EP2739893B1 patent drawingFigure 3

AI summary

A locking mechanism for a stop flange is provided with a screw having a head with at least one circumferential channel, and a screw gasket disposed on the at least one circumferential channel. A bushing receives the head in a cavity that forms a housing for the head and screw gasket. The bushing may be provided with a lip that engages a shoulder on a radial bore in a stop flange.