Inflatable Pipe Purging Bladders for Faster Inert Gas Welding
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Solution Overview
Problem
Existing pipe purging methods are inefficient in terms of time and gas volume required to achieve a predetermined oxygen level, and they fail to effectively minimize the mixing of purge gas with the atmosphere, especially in complex industrial pipe systems with varying diameters and configurations.
Innovation Solution
An apparatus and method using an internal pipe inerting device with inflatable bladders and multiple diffusers to match the purge gas area to the pipe diameter, ensuring a sealed and efficient distribution of inert gas within the pipe, minimizing atmospheric contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a small diameter diffuser is used to introduce purge gas into the pipe, then the purge system can be simpler and easier to install, but the purge gas mixes with the atmosphere for considerable time reducing purging efficiency
Solution Approach 1:
The pipe interior is divided into multiple sealed sections using inflatable bladders positioned at intervals along the pipe. Each section can be purged independently, allowing the purge process to be parallelized and completed much faster than purging the entire pipe length in one continuous flow.
Solution Approach 2:
Multiple diffusers are positioned at different locations and orientations within each sealed section to create a three-dimensional distribution pattern of purge gas. This ensures comprehensive coverage and rapid displacement of atmospheric gases throughout the entire section volume.
2Length of moving object
If the diffuser diameter is much smaller than the pipe inside diameter, then the diffuser can fit through the pipe, but the purge gas area does not match the pipe diameter leading to extensive mixing
Solution Approach 1:
Multiple diffusers of varying sizes are nested within each other or positioned concentrically to create an expanded effective purge gas distribution area. This allows the system to maintain small individual diffuser components that can be inserted through the pipe while collectively providing coverage matching the full pipe cross-section.
Solution Approach 2:
The purge gas introduction is segmented into multiple diffusers distributed throughout the sealed section rather than relying on a single large diffuser. This segmentation allows each diffuser to be small enough for insertion while the collective arrangement achieves full cross-sectional coverage.
3Loss of time
If inflatable bladders are used to seal off pipe sections, then purging time and gas volume are reduced, but the system becomes more complex and may not be applicable to all pipe configurations
Solution Approach 1:
The bladders are designed to be inflatable and deflatable, transforming from a compact transport state to an expanded sealing state during operation. This dynamic transformation allows the same component to serve multiple functions: easy insertion through small openings, effective sealing of large pipe sections, and simple removal after purging.
Solution Approach 2:
The bladder-diffuser assembly is designed as a universal module that can be adapted to various pipe diameters and configurations. The same basic component design can seal and purge different sized sections by adjusting inflation pressure and bladder positioning, making the system applicable across multiple pipe types without requiring completely different equipment.
4Productivity
If multiple diffusers are used to match purge gas area to pipe diameter, then purge efficiency increases, but the device complexity increases
Solution Approach 1:
The multi-diffuser system is segmented into modular units that can be independently positioned and activated. Each diffuser is a simple component, but their coordinated arrangement within the sealed section creates efficient three-dimensional gas distribution. The segmentation allows for scalable configuration based on pipe size and section length.
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
This approach significantly reduces the time and gas volume needed for purging by ensuring the purge gas evenly fills the pipe, maintaining a stable inert atmosphere during welding, thereby enhancing the structural integrity and safety of welded pipes.
Implementation Method 1
2 inflatable bladders installed on each side of the joint to be welded, sealing off a small section
Implementation Method 2
purge gas is introduced to the sealed off section through a small gas diffuser
Data Source
Figure 1
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AI summary
A method and apparatus for providing an inert atmosphere to the inside of a piping assembly prior to and during welding, including a canister 101, and a bladder 102 which surrounds the canister 101 and fits inside of a piping assembly to be welded 119. The canister 101 including a purge gas inlet connection 106 fluidically connected to a bladder fill conduit 107, a bladder return conduit 108 fluidically connected to a pressure relief device 109, the pressure relief device 109 fluidically connected to a reduced pressure purge gas conduit 110, a primary purge gas diffuser 111, a secondary purge gas diffuser 113, a tertiary purge gas diffuser 115, and purge gas exit holes 116. Wherein the bladder fill conduit 107 is configured to introduce purge gas into the bladder 102. Wherein the bladder 102 is configured to expand and form a seal between the canister 101 and the piping assembly to be welded 119. And wherein the bladder return conduit 108 is configured to evacuate excess purge gas from the bladder 102.