Variable Taper Pin Plug Assembly for Wide Range Heat Exchanger Sealing
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Solution Overview
Problem
Existing plug assemblies struggle to create an effective seal within a wide range of tube inner diameters while maintaining high pressure holding capability, as conventional plugs with consistent taper angles are limited in either diameter accommodation or pressure resistance.
Innovation Solution
A plug assembly with a pin having variable taper angles along its length, transitioning from a steeper taper at one end to a shallower taper at the other, allowing for a high-pressure seal across a broader range of tube diameters without increasing installation force or length.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a consistent relatively-steep conical pin angle is used to accommodate a large range of tube diameters, then the sealing diameter range is improved, but the pressure holding capability deteriorates due to less radial force compressing the ring into the tube
Solution Approach 1:
The pin is divided into different sections along its length, with each section having a different taper angle. The first section has a steeper taper angle for initial ring expansion, while the second section has a shallower taper angle for maintaining high radial compressive force. This local differentiation allows the pin to accommodate a wide range of tube diameters while maintaining high pressure holding capability.
2Reliability
If a consistent relatively-shallow conical pin angle is used to achieve high pressure holding capability, then the pressure holding capability is improved, but the expansion range of the ring is limited relative to range of tube inner diameter
Solution Approach 1:
The pin features a first section with a shallower taper angle that provides high radial force for pressure holding, and a second section with a steeper taper angle that enables greater ring expansion. This local differentiation allows the plug to achieve both high pressure holding capability and accommodation of a wide range of tube inner diameters.
3Adaptability or versatility
If the pin length is increased to expand the ring further for larger tube diameters, then the sealing diameter range is improved, but the device complexity and installation force requirements increase
Solution Approach 1:
Instead of increasing pin length, the invention changes the taper angle parameter along the pin length. The variable taper angles allow the ring to expand to larger diameters through geometric optimization rather than simply extending the pin length, thereby accommodating larger tube diameters without increasing device complexity or installation force requirements.
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
Enhances pressure holding capability by 50% to 75% compared to conventional wide-range plugs, ensuring a high-pressure seal even at larger diameters, thus improving the reliability and efficiency of heat exchanger repairs.
Implementation Method 1
an elongated pin having a conical shape with a constant taper along its length which is slidably received within the ring for expanding the ring outwardly when the pin is pulled axially relative to the ring
Implementation Method 2
the ring expands and compresses against an inner diameter wall of a tube thereby forming a metal-to-metal seal
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
A pin and ring-type plug assembly (38) for plugging a heat exchanger tube to provide a leak resistant seal is provided. The plug assembly (38) is designed such that it can be used to form a high-pressure seal relative to a wide of range of tube inner diameters. The angle of taper of the pin (30, 42) varies along a length of the pin (30, 42) such that the angle of taper is steepest at or adjacent a nose section (32, 44) of the pin (30, 42) and is shallowest at or adjacent an end section (34, 46) of the pin (30, 42).