Gate Insert Valve Sealing for Pressurized PCCP Replacement
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Solution Overview
Problem
Existing methods for installing valves in prestressed concrete cylinder pipes (PCCP) are complex and risky, as they require large mechanical joints that can lead to blowouts or cylinder ruptures, especially when traditional butterfly valves are not used, such as in raw sewage systems.
Innovation Solution
A method and replacement valve assembly that allows for the installation of a gate valve by temporarily enclosing short areas, using a valve body with sloped surfaces and elastomeric seals to create a fluid-tight engagement with pipe ends, enabling valve installation on PCCP and other pipe types without stripping long areas of wire, and utilizing a cutting mechanism to prepare the pipe for valve insertion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If long areas of the cylinder are stripped of wire to install valves, then valve installation is enabled, but the risk of blowout or cylinder rupture increases
Solution Approach 1:
The sealing system is segmented into multiple components: elastomeric seals positioned at pipe ends, cut-covering assemblies with sloped surfaces, and a valve body with central chamber. This segmentation allows sealing to occur at discrete locations rather than requiring long stripped areas, maintaining cylinder integrity while enabling valve installation.
Solution Approach 2:
Elastomeric seals act as intermediaries between the valve assembly and the pipe ends. These seals create fluid-tight engagement without requiring the cylinder wire to be stripped over long distances, thus enabling valve installation while preserving cylinder structural integrity.
2Strength
If complex bells and spigots are used for joining valve ends, then mechanical joining is achieved, but the joining mechanism becomes much larger than the pipe diameter
Solution Approach 1:
The sealing mechanism transitions from external mechanical joining (bells and spigots) to internal sealing. The elastomeric seals and cut-covering assemblies create sealing within the pipe bore, eliminating the need for large external joining mechanisms and reducing overall assembly size.
Solution Approach 2:
Elastomeric seals provide flexible sealing surfaces that conform to pipe ends and valve components. This flexible sealing approach replaces rigid bells and spigots, achieving strong fluid-tight joints with much smaller dimensions.
3Reliability
If traditional sealing methods are used, then fluid-tight sealing is achieved, but long areas of the cylinder must be stripped of wire
Solution Approach 1:
The elastomeric seals and cut-covering assemblies are pre-positioned at the pipe ends before valve installation. This preliminary sealing arrangement ensures fluid-tight engagement is achieved at specific locations without requiring extensive wire stripping, thereby reducing the length of affected cylinder areas.
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 safe and efficient installation of valves in pressurized pipelines by creating temporary fluid-tight seals and allowing for the use of smaller, standard gate valves, reducing the risk of pipe damage and ensuring secure sealing without the need for extensive wire removal.
Implementation Method 1
a right side elastomeric seal having an exterior surface and an interior surface, wherein the exterior surface of the right side elastomeric seal contacts an interior surface of the right side cylinder and the interior surface of the right side elastomeric seal contacts the exterior surface of the right side tube
Implementation Method 2
a right side sloped surface formed in or mechanically connected to the left side of the right side tube, the sloped surface having an angle of less than 90° and extending into the central chamber
Data Source
AI summary
A method of cutting and removing a section of pipe, such as prestressed concrete cylinder pipe, and installing a replacement gate valve while the pipeline is fully pressurized by use of a replacement valve body. The replacement valve body includes two cylinders that match the openings of the cut pipe, and inside each of the two cylinders is a cut-covering assembly which includes a cylindrical elastomeric seal and a spring tube. The replacement valve body further includes a linear moving gate in a central portion of the valve, and when the cylinder ends of the replacement valve body are positioned adjacent the bores of cut pipe ends, the gate can be moved to push the elastomeric seals of each of the cut-covering assemblies into the bores of the cut pipe ends, thereby covering gaps created when the pipe was cut and placing the pipe ends in fluid-tight engagement with the replacement valve body.