Weld Test Plug Seal Expansion for Variable-Diameter Vessels
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Solution Overview
Problem
Current weld test plugs face challenges in efficiently isolating and testing sections of vessels due to difficulties in radially expanding and contracting seals, especially in vessels with varying diameters and complex geometries, leading to potential deformation and impaired functionality during pressure testing.
Innovation Solution
A weld test plug design featuring an actuator rod with a part expander, annular seal, and axial stop, where the actuator rod causes the part expander to radially expand the annular seal, which abuts the axial stop to form a fluid-tight seal, and includes features like frustoconical wedges and collet fingers to enhance sealing and contraction capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional weld test plugs are used to isolate and test vessel sections, then pressure testing can be performed, but the seals deform and functionality is impaired due to difficulty in radially expanding and contracting
Solution Approach 1:
The weld test plug incorporates a dynamic expansion mechanism where the actuator rod can be rotated to radially expand the seal from a contracted state to a expanded state. This dynamic capability allows the seal to adapt to varying vessel diameters and geometries, ensuring reliable sealing while maintaining ease of operation through simple rotational actuation.
Solution Approach 2:
The seal's radial dimension is changed through actuation of the actuator rod, transitioning from a contracted configuration (for insertion and storage) to an expanded configuration (for sealing). This parameter change enables the same component to function effectively across vessels with varying diameters without deformation or loss of functionality.
2Adaptability or versatility
If seals are radially expanded to seal against vessels with varying diameters, then adaptability is improved, but deformation and impaired functionality occur
Solution Approach 1:
The dynamic expansion mechanism allows the seal to progressively adapt to different vessel diameters through controlled rotation of the actuator rod. The seal maintains its structural integrity during expansion by following a controlled deformation path, preventing permanent damage while achieving compatibility with various vessel geometries.
Solution Approach 2:
The seal is designed in a pre-contracted state that preserves its structural integrity during storage and insertion. The expansion to adapt to vessel diameter is performed only when needed, through controlled actuation, preventing premature deformation while maintaining adaptability to different vessel sizes.
3Adaptability or versatility
If complex geometries are tested with conventional plugs, then testing capability is achieved, but removal difficulty increases
Solution Approach 1:
The dynamic contraction mechanism allows the seal to be easily retracted from the expanded sealing position back to the contracted removal position by reversing the actuator rod rotation. This enables simple removal and reinstallation of the weld test plug from complex vessel geometries without permanent deformation or damage to the seal.
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 design ensures effective sealing and pressure testing while minimizing deformation and ease of removal, reducing safety risks and costs by allowing for efficient sectioning and pressure testing of vessels with varying diameters and complex geometries.
Implementation Method 1
The first axial portion forms a wedge that is tapered with decreasing radius in a direction toward the annular seal. The first axial portion is frustoconical in shape.
Implementation Method 2
The annular seal comprises elastomeric material. The annular seal to radially expand and abut the axial stop.
Implementation Method 3
The axial stop comprises collet fingers. The collet fingers are biased to radially contract during resetting of the weld test plug.
Data Source
AI summary
A weld test plug has a flange; an actuator rod mounted to the flange, the actuator rod having: a part expander; an annular seal; and an axial stop; in which the actuator rod is connected to, during use, cause the part expander to actuate: the axial stop to move in a radially outward direction relative to the actuator rod; and the annular seal to radially expand and abut the axial stop. A method includes inserting an actuator rod into an open end of a vessel, the actuator rod carrying an annular seal, and an axial stop; sealing the open end of the vessel around the actuator rod; operating the actuator rod to actuate: the axial stop to move in a radially outward direction relative to the actuator rod; and the annular seal to radially expand to abut the axial stop and seal against an inner circumferential surface of the vessel.