Pipe Joint Gland With Spring-Biased Gripper Retention
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Solution Overview
Problem
Mechanical joint pipe connections lack a positive retention mechanism, leading to potential seal compromise and pipe failure under high tension forces or conditions like water hammer, and existing joint restraint mechanisms can cause deformation, creep, and cracking of the pipe end.
Innovation Solution
A gland with a joint restraint assembly featuring gripper arms and a spring bias, which can be selectively configured to engage the pipe surface, preventing removal and providing a secure seal without exerting excessive stress on the pipe.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a joint restraint mechanism is incorporated to provide positive retention, then reliability is improved, but the pipe length is subjected to high stresses which can lead to deformation, creep, and cracking
Solution Approach 1:
A gripper component acts as an intermediary between the joint restraint assembly and the pipe end. The gripper engages the outer surface of the pipe end with gripping surfaces that distribute retention forces, preventing direct high-stress concentration on the pipe end while still providing positive retention against pull-out forces
Solution Approach 2:
The gripping surfaces of the gripper are designed with specific local properties (friction characteristics, contact area distribution) to engage the pipe end outer surface in a controlled manner. This localized engagement quality ensures adequate retention while minimizing harmful stress concentration that could cause deformation or cracking
2Reliability
If existing joint restraint mechanisms are used to prevent seal compromise, then reliability is improved, but the plain end of the pipe length is subjected to high stresses which can lead to failure
Solution Approach 1:
The gripper serves as a stress-distributing intermediary between the restraint mechanism and the pipe end. It translates the retention force into distributed contact pressures on the pipe end outer surface, preventing stress concentration that would compromise the strength of the plain end
Solution Approach 2:
The gripper is designed to engage the pipe end before high tension forces or water hammer effects occur. This preliminary engagement cushions the pipe end by distributing forces evenly, preventing sudden stress spikes that could lead to failure under extreme conditions
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
The solution ensures a secure and reliable seal under various conditions, preventing pipe failure and deformation while allowing for easy installation and adjustment to different pipe sizes, reducing the risk of leaks and environmental contamination.
Implementation Method 1
a spring biasing the gripper to move inwards towards the gland axis
Implementation Method 2
the gland is tightened by a series of bolts which draw the gland towards the female socket, thereby compressing the gasket. Compression of the gasket causes the gasket to engage an outer surface of the plain end of the pipe length, thereby forming a seal
Implementation Method 3
The lack of a positive retention mechanism can compromise the seal or lead to the plain end pulling out of the female socket when the connection is subjected to high tension force
Data Source
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AI summary
A gland includes an annular ring, the annular ring defining a gland bore, the gland bore defining a gland axis extending through the annular ring; and a joint restraint assembly, the joint restraint assembly including a restraint base, the restraint base attached to the annular ring, the restraint base defining a restraint pocket, the restraint base including a structural rail; a gripper, the gripper disposed within the restraint pocket and configured to move in the restraint pocket; a spring biasing the gripper to move inwards towards the gland axis; and a cover contacting at least a portion of the restraint base.