Expandable Sewer Lining Tube for Variable Pipe Diameters
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing lining tubes for reconditioning sewer pipes require multiple types to accommodate varying diameters, leading to logistical challenges and potential mechanical weaknesses due to overstretching or incomplete curing, especially when diameter changes abruptly.
Innovation Solution
A lining tube design with an inner film tube featuring a predetermined breaking point allows radial expansion beyond 10%, combined with a radially expandable layer of fiber material impregnated with curable resin, ensuring airtightness and complete curing across varying pipe diameters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the lining tube is manufactured with an outside diameter 5 to 10% smaller than the sewer pipe inside diameter to enable expansion and improve surface finish, then the contact between lining tube and sewer wall is improved, but the stretching capacity is limited to less than 10% to avoid damaging the inner film tube
Solution Approach 1:
The inner film tube is divided into two functional sections: a first section with high stretching capacity (at least 10%, preferably 20-50%) that can expand to accommodate sewer pipe diameter variations, and a second section that maintains the required manufacturing precision and surface finish. This segmentation allows different parts of the same tube to have different stretching characteristics.
Solution Approach 2:
Different sections of the inner film tube are assigned different local qualities: the first section is designed with material properties and structural characteristics that enable high elasticity and stretching, while the second section is designed with properties that ensure dimensional stability and precise surface finish after curing.
Solution Approach 3:
The inner film tube transitions from a static, uniform structure to a dynamic, differentiated structure where the first section can dynamically expand to adapt to varying sewer pipe diameters, while the second section maintains its form for precise manufacturing requirements.
2Adaptability or versatility
If more than 40 different basic types of lining tubes with respective nominal diameters are manufactured to accommodate sewer pipes with diameters between 150 mm and 1000 mm, then each sewer diameter can be optimally adapted, but the logistical effort and production cost increase greatly
Solution Approach 1:
A single universal lining tube design with a differentiated inner film tube can serve multiple sewer pipe diameters (150-1000 mm) by adjusting the expansion level of the first section, eliminating the need to manufacture and stock 40+ different specialized tube types. The same basic tube structure adapts to different applications through controlled expansion.
Solution Approach 2:
Instead of changing the fundamental design parameters (nominal diameter, wall thickness, etc.) to create different tube types, the invention changes the operational parameter of expansion level. By controlling how much the first section expands, the same tube can adapt to different sewer pipe diameters without requiring different manufacturing specifications.
3Adaptability or versatility
If the inner film tube is stretched beyond 10% capacity, then greater diameter adaptation is possible, but the sensitive transparent inner film may be overstretched and damaged causing resin ejection
Solution Approach 1:
The inner film tube is segmented into a first section designed to bear the stretching load (with at least 10% elongation capacity) and a second section that remains within safe stress limits. This protects the integrity-critical areas from damage while allowing necessary expansion in the first section.
Solution Approach 2:
The first section is pre-designed with high elasticity and stretching capacity to absorb the expansion stress before it can propagate to and damage the second section. This preemptive design cushions the critical integrity areas from the stresses of large-diameter adaptation.
4Ease of operation
If the lining tube diameter is made larger than the sewer pipe inside diameter, then easier installation is possible, but the laminate and outer film tube form folds that prevent complete through-curing by UV light
Solution Approach 1:
The lining tube uses a dynamic expansion approach where the tube is installed at a smaller diameter without folds, then expanded in-situ to the final diameter. This ensures the laminate remains smooth and UV light can penetrate uniformly for complete curing, while still achieving easy installation through the expansion mechanism.
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
Enables seamless adaptation to different sewer pipe diameters using a single lining tube type, reducing logistical efforts and ensuring high mechanical strength and leak-tightness without shadow formation or resin ejection.
Implementation Method 1
the inner film tube (10) has a connecting section (12) which extends in the longitudinal direction thereof and connects two mutually parallel circumferential portions (10a, 10b) of the inner film tube (10) to form a circumferentially closed inner film tube
Implementation Method 2
said connecting section (12) has a predetermined breaking point (14) which can be parted in the circumferential direction by introducing a pressure medium, in particular compressed air
Implementation Method 3
a radially expandable layer of fiber material (20) which is arranged around the tube and which has been impregnated with a curable reaction resin
Implementation Method 4
cured by means of light from a source of UV radiation or, alternatively, by introducing superheated steam
Implementation Method 5
after being pulled in are closed at their ends by means of packers and expanded by means of compressed air
Data Source
AI summary
A lining tube for reconditioning a defective sewer pipe has an inner film tube, around which is disposed a radially expandable layer of fiber material that is impregnated with a curable reactive resin. The inner film tube has a connecting section that extends in longitudinal direction thereof and connects two circumferential portions of the inner film tube that run parallel to one another to give an inner film tube which is continuous over its circumference and has a defined nominal diameter. The connecting section has an intended fracture site that extends along the inner film tube and can be parted by introducing a pressure medium into the inner film tube in circumferential direction, in order to expand the inner film tube and the layer of fiber material disposed thereon radially beyond the nominal diameter. There is also described a method of producing and of installing such a lining tube.