Spun Metal Fluid Conduit Fittings With Matched Yield Strength
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional forging methods for manufacturing fluid conduit fittings result in lower mechanical properties compared to the tubing they are welded to, necessitating over-engineering and increased thickness, leading to bulkiness and expense in subsea umbilicals.
Innovation Solution
A method involving cold-forming a workpiece to create a tubular metal fitting with enhanced yield strength by spinning, followed by heat treatment and welding it to tubing of the same material grade, ensuring compatibility and improved mechanical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional forging methods are used to manufacture fittings, then the fittings can be produced, but their mechanical properties are lower than the tubing they are welded to
Solution Approach 1:
The patent applies parameter changes by transitioning from conventional forging to cold-forming processes. This changes the manufacturing parameters (temperature, deformation method) to achieve superior mechanical properties in the fitting that match or exceed the tubing properties. The cold-forming process creates a finer grain structure and higher strength characteristics in the fitting material.
Solution Approach 2:
The patent replaces the conventional forging mechanical system with a cold-forming mechanical system. Instead of using high-temperature forging equipment, the invention employs cold-forming equipment that applies controlled deformation at ambient or lower temperatures, resulting in improved mechanical properties through work hardening and grain refinement.
2Strength
If fitting thickness is increased to compensate for lower mechanical properties, then strength is improved, but the conduit becomes bulkier and more expensive
Solution Approach 1:
By changing the manufacturing process parameters from forging to cold-forming, the patent achieves higher strength properties in thinner-walled fittings. This allows the fitting to maintain required strength levels without increasing thickness, thereby reducing weight and bulkiness of the overall conduit assembly.
Solution Approach 2:
The patent applies local quality by ensuring the fitting has uniformly high mechanical properties throughout its structure through cold-forming. This consistent high quality allows for optimized wall thickness without compromising strength, whereas conventional forging would require increased thickness to compensate for property variations and lower baseline strength.
3Ease of manufacture
If conventional forging is used, then manufacturing is simpler, but material properties do not match tubing requirements
Solution Approach 1:
The patent changes the manufacturing process parameters to cold-forming, which provides better control over material properties. While cold-forming may be slightly more complex than forging, it offers precise control over grain structure, strength, and other mechanical properties through controlled deformation parameters, temperature, and strain rate.
Solution Approach 2:
The patent implements feedback mechanisms in the cold-forming process to monitor and control material properties during manufacturing. This includes real-time monitoring of deformation parameters, temperature control, and post-processing inspection to ensure the fitting meets the required mechanical property specifications that match the tubing.
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 method achieves compatible mechanical properties between fittings and tubing, reducing material thickness and cost while maintaining structural integrity in subsea umbilicals.
Implementation Method 1
cold-forming a workpiece in a spinning operation to make the fitting, the material of the workpiece initially having a yield strength below that of the material of the tubing; increasing the yield strength of the material of the workpiece by virtue of the spinning operation that forms the fitting from the workpiece
Implementation Method 2
cold-forming a workpiece in a spinning operation to make the fitting... followed by heat treatment and welding it to tubing
Data Source
AI summary
A method of making a fluid conduit includes at least one tubular metal fitting in fluid communication with metal tubing. The conduit is apt to be incorporated into a subsea umbilical. The fitting is made by cold-forming a workpiece in a spinning operation. The workpiece material initially has a yield strength below that of the tubing material. The invention corrects or reduces this mismatch between the yield strength of the tubing material and the initial yield strength of the workpiece material by: assessing the yield strength of the tubing material; assessing the increased yield strength of the workpiece material by virtue of the spinning operation; and before welding the fitting to the tubing, comparing the increased yield strength of the workpiece material with the yield strength of the tubing material.