Eccentric Test Plug for Pipe Elbow Sealing

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Solution Overview

Problem

Conventional test plugs fail to form a reliable, fluid-tight seal in pipe elbows during hydrotesting due to the complex inner geometries of elbow joints, requiring additional straight pipe sections for fitting, which is time-consuming and inefficient.

Innovation Solution

The development of test plugs with eccentrically aligned components, including a seal, grippers, and a shaft, that self-adjust and float to conform to the inner pipe geometry, allowing for a secure grip and seal in both elbow and straight pipe sections without the need for additional pipe sections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional test plugs are used in pipe elbows, then the testing process requires additional straight pipe sections to be welded and removed, but this significantly increases time consumption and operational complexity

Engineering Contradiction:
Improvetesting efficiencyVSAvoidtime for adding and removing pipe sections
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The test plug incorporates an asymmetric design where the sealing surface and gripper elements are positioned eccentrically relative to the shaft centerline. This asymmetric configuration allows the plug to self-align with the curved inner geometry of pipe elbows, creating effective seals and secure grips without requiring additional straight pipe sections, thereby eliminating time-consuming welding and removal operations

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The test plug employs dynamic adjustment mechanisms including floating camming elements and movable gripper segments that can self-adjust their positions during insertion and operation. This dynamic capability enables the rigid plug body to adapt to the curved geometry of pipe elbows, achieving proper sealing and gripping positions automatically without requiring manual intervention or additional pipe sections

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If conventional test plugs are used in pipe elbows, then additional pipe modifications are required, but this increases device complexity and operational difficulty

Engineering Contradiction:
Improveease of installing test plugVSAvoidcomplexity of pipe preparation
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The asymmetric positioning of sealing surfaces and gripper elements relative to the shaft centerline enables the test plug to naturally conform to the curved geometry of pipe elbows. This design eliminates the need for complex pipe modifications such as welding straight sections, thereby simplifying the installation process and reducing operational difficulty while maintaining ease of use

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The test plug incorporates self-aligning and self-adjusting features that automatically adapt to the pipe elbow geometry during insertion. The floating camming elements and movable components self-position to achieve proper sealing and gripping without requiring external assistance or complex preparation procedures, thereby simplifying operation and reducing device complexity

Inventive Principle:
Principle #25Self-service

3Reliability

If conventional test plugs are used in pipe elbows, then reliable sealing cannot be achieved due to complex inner geometries, but modifying the plug design increases manufacturing complexity

Engineering Contradiction:
Improveseal integrityVSAvoidmanufacturing complexity of test plug
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The asymmetric configuration of sealing surfaces and gripper elements is designed to match the typical curved geometry of pipe elbows. This asymmetric design achieves reliable sealing by positioning the sealing surface to contact the curved inner wall at the optimal location, ensuring fluid-tight seals without requiring overly complex manufacturing processes. The eccentric offset can be implemented using standard machining operations

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The dynamic adjustment mechanisms including floating camming elements and movable gripper segments provide adaptability to variations in pipe elbow geometry. These mechanisms automatically self-adjust during insertion to achieve proper sealing contact, ensuring reliable seals across different pipe configurations. The dynamic features are implemented using conventional mechanical components that are manufacturable with standard processes

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3338019B1Test plug for a pipe elbow
Publication Date: 2019.10.09 EST GROUP
  • EP3338019B1 patent drawingFigure 1
  • EP3338019B1 patent drawingFigure 2
  • EP3338019B1 patent drawingFigure 3~4

AI summary

A test plug (10, 110, 210) for insertion into and plugging of an open end of an elbow pipe is provided. The test plug (10, 110, 210) includes a resilient sealing element (24, 124, 224) and set of gripper segments (28, 128, 228) carried on a shaft (12, 112, 212). The set of gripper segments (28, 128, 228) are movable relative to the shaft (12, 112, 212) between pipe-gripping and pipe-non-gripping positions such that, when the test plug (10, 110, 210) is placed in sealing and gripping engagement relative to an inner diameter wall of an elbow pipe, the set of gripper segments (28, 128, 228) are positioned in eccentric relation to at least one of the sealing element (24, 124, 224) and the shaft (12, 112, 212).