Anti-Rotation Keyed Pipe Connection Without Axial Compression

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Solution Overview

Problem

Current anti-rotation key designs for large diameter pipes in offshore hydrocarbon drilling often require specialty tools, generate axial compressive loads that deform connectors, and can be difficult to unlock, leading to reduced cyclic load life and issues with metal shavings.

Innovation Solution

An anti-rotation key system that aligns a slot on the pin with a series of grooves on the box, allowing a key to be inserted without axial or radial compression, maintaining the load path and allowing for easy insertion and removal without deforming materials.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If current anti-rotation key designs are used to prevent loosening of threaded connectors, then anti-rotation capability is improved, but axial compressive load increases causing connector deformation

Engineering Contradiction:
Improveanti-rotation capabilityVSAvoidconnector deformation
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The invention replaces the traditional mechanical anti-rotation key system that applies axial compressive load with a slot-based locking mechanism. The key is positioned within a slot that prevents rotation without requiring axial compression, thereby eliminating the harmful deformation effect while maintaining anti-rotation capability.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention changes the operational parameters of the anti-rotation key by eliminating the need for axial compressive load. Instead of forcing the key into the connector with axial force, the key is inserted into a pre-formed slot that provides rotational constraint through lateral engagement, fundamentally changing how the anti-rotation function is achieved.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If explosive powered guns are used to set the locking mechanism, then installation capability is improved, but device complexity increases

Engineering Contradiction:
Improveinstallation capabilityVSAvoidspecialty tools required
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The slot is pre-formed in the connector during manufacturing, eliminating the need for field drilling or complex installation tools. The anti-rotation key simply slides into the existing slot, making the system self-servicing during installation without requiring explosive guns or specialized equipment.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The slot is created in advance during connector manufacturing rather than during field installation. This preliminary action eliminates the need for complex installation procedures and specialty tools, allowing simple key insertion to complete the anti-rotation setup.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If drilling is performed to install the locking member, then anti-rotation capability is improved, but harmful factors increase due to metal shavings

Engineering Contradiction:
Improveanti-rotation capabilityVSAvoidmetal shavings
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The invention extracts the harmful drilling operation from the installation process. By pre-forming the slot and simply inserting the key, the system eliminates metal shavings generation while maintaining effective anti-rotation locking capability.

Inventive Principle:
Principle #2Taking out (Extraction)

4Reliability

If anti-rotation keys with teeth that bite into connectors are used, then anti-rotation capability is improved, but cyclic load life decreases due to permanent deformation

Engineering Contradiction:
Improveanti-rotation capabilityVSAvoidcyclic load life
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The invention replaces the tooth-biting mechanism that causes permanent deformation with a slot-based lateral locking system. The key engages the slot walls sideways rather than biting into the connector material, eliminating stress concentration points and preserving the connector's fatigue life under cyclic loading.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention changes the engagement mechanism from axial compression with tooth biting to lateral engagement within a slot. This parameter change eliminates the permanent deformation that reduces cyclic load life while maintaining effective anti-rotation capability.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3455448B1Drop in Anti-rotation key
Publication Date: 2023.05.31 VETCO GRAY INC
  • EP3455448B1 patent drawingFigure 1
  • EP3455448B1 patent drawingFigure 2
  • EP3455448B1 patent drawingFigure 3~4

AI summary

A tubular member connection system (11) includes a box (27) having an inner diameter surface and internal box threads (29). A pin (15) has an outer diameter surface and external pin threads (17), the pin threads shaped to mate with the box threads to releasably secure the pin to the box so that the pin and the box are aligned along a common central axis (16). A slot (35) is located in one of the inner diameter surface and the outer diameter surface, the slot having a pair of side-walls (37). An anti-rotation profile (47) is located in the other of the inner diameter surface and the outer diameter surface. A key (41) is sized to fit within the slot and have a key profile shaped to engage the anti-rotation profile (47) and prevent relative rotational movement between the box and the pin.