Expansion Restrictor Sleeve for Pipe Liner Inflation at Bends
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Solution Overview
Problem
Existing pipe repair methods using liners face issues with fluid trapping between the liner and the pipe wall, particularly at bends, leading to reduced internal diameter and flow restrictions.
Innovation Solution
A sleeve with varying diameters is used in conjunction with a bladder and liner, allowing controlled expansion to minimize fluid trapping by expanding first at locations requiring less pressure, such as bends, and then progressively expanding outward, ensuring complete inflation without trapping fluids.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a bladder is inflated to press the liner against the pipe wall, then the liner is secured in place, but fluid becomes trapped between the liner and pipe wall at bends causing reduced internal diameter
Solution Approach 1:
The bladder is divided into multiple independently inflatable segments or zones along its length. Each segment can be inflated separately to control the expansion sequence, allowing fluid to be progressively displaced from one section to another rather than being trapped in a single location.
Solution Approach 2:
The bladder is inflated in a predetermined sequence starting from sections away from bends first, then progressively inflating sections near bends. This preliminary action prevents fluid from becoming trapped at critical locations by establishing pressure zones that systematically push fluid toward designated escape paths before the liner contacts the pipe wall at bend areas.
2Manufacturing precision
If the bladder is inflated uniformly, then the liner expands evenly, but fluid pockets form at bends preventing complete inflation
Solution Approach 1:
The inflation system transitions from static uniform pressure to dynamic sequential pressure control. Each bladder segment can be inflated at different pressures and rates, allowing the system to adapt to the varying geometry of the pipe (straight sections vs. bends) and systematically eliminate fluid pockets while maintaining overall expansion uniformity.
Solution Approach 2:
The inflation process uses periodic or staged pressure application rather than continuous uniform pressure. The bladder segments are inflated in cycles or stages, with each stage targeting specific sections to displace fluid before moving to the next section, creating a rhythmic expansion pattern that prevents fluid trapping.
3Manufacturing precision
If high pressure is applied to expand the liner at bends, then the liner contacts the pipe wall, but fluid cannot escape and the liner inflates against the fluid pocket
Solution Approach 1:
The system extracts or removes fluid from the expansion zone by providing dedicated fluid escape paths or collection chambers. As each bladder segment inflates, it pushes fluid toward escape channels that lead to collection areas, preventing fluid accumulation that would otherwise require excessive pressure to overcome.
Solution Approach 2:
The bladder segments act as intermediaries between the inflation pressure source and the liner. By controlling which segments inflate first and at what pressure, the system mediates the force transmission to the liner, distributing pressure gradually and preventing sudden high-pressure spikes that would occur when inflating against trapped fluid.
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 controlled expansion method effectively prevents fluid trapping, maintaining the internal diameter and ensuring uniform inflation, thereby reducing flow restrictions and enhancing the repair process efficiency.
Implementation Method 1
The bladder is a fluid sealed bladder capable of expanding upon introducing a fluid, such as air, into the bladder
Implementation Method 2
The bladder and sleeve are made from an expandable material, such as an elastomer or polymer
Implementation Method 3
Light-activated resins help overcome certain drawbacks in other types of resins because the resin in the impregnated liner does not begin to cure until it is exposed to the UV light
Data Source
AI summary
An assembly and method for repairing a pipeline. The assembly may include a sleeve positioned between a bladder and a liner. The sleeve includes a first portion having a larger diameter than a second portion. The larger diameter at the first portion of the sleeve allows the sleeve to expand outward with less pressure. Upon the introduction of fluid pressure into the bladder, the bladder, sleeve, and liner expand radially outward at the first portion of the sleeve first. Then, as pressure inside the bladder increases, the remainder of the assembly expands radially outward toward the pipe in a serial fashion longitudinally away from the first portion. In this manner the user can control which area of the assembly is inflated and expanded first by positioning the first portion of the sleeve at the appropriate location.