Subsea Pipe Ring Collapse Testing Apparatus
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Solution Overview
Problem
The design and testing of deep-water subsea pipelines face challenges due to external pressure collapse, which is not adequately addressed by conventional methods, particularly in ultra-deep water installations where full-scale pipe joint pressure testing is expensive and inconvenient, and existing external pressure collapse tests on ring specimens lack accuracy.
Innovation Solution
An apparatus and method for testing ring specimens cut from pipes, comprising first and second test chamber sections, sealing means, a hydraulic ram, and sensors to measure force, movement, and strain, allowing for accurate determination of the external pressure collapse resistance of pipes by simulating deep-water conditions and ensuring correct assembly of the test ring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If full-scale pipe joint collapse tests are conducted, then design accuracy and reliability are improved, but test cost and operational complexity increase significantly
Solution Approach 1:
The patent divides the full-scale pipe joint into ring specimens that can be cut and tested individually in a smaller test chamber. This segmentation allows the test facility to be much smaller and simpler while still providing reliable collapse pressure data through properly scaled ring specimens that capture the critical collapse behavior.
Solution Approach 2:
The patent creates ring specimens that serve as representative copies of the full-scale pipe joint behavior. By carefully selecting ring dimensions and testing conditions, the ring specimens replicate the collapse pressure characteristics of the actual pipe joint, enabling accurate design validation without requiring full-scale testing facilities.
2Ease of manufacture
If ring specimen tests are used instead of full-scale tests, then test cost and facility requirements are reduced, but measurement accuracy may be compromised
Solution Approach 1:
The patent incorporates multiple sensors (displacement transducers, strain gauges, pressure transducers) that provide real-time feedback on ring specimen behavior during testing. This comprehensive measurement system ensures accurate capture of collapse pressure and deformation characteristics, maintaining measurement precision despite the reduced scale of the test specimen.
Solution Approach 2:
The patent carefully controls and varies key parameters such as ring specimen dimensions, wall thickness, and testing pressure rates to optimize the correlation between ring specimen behavior and full-scale pipe joint performance. By adjusting these parameters, the test facility can achieve accurate measurements that reflect actual field conditions.
3Measurement precision
If sealing means are added to ensure correct ring assembly, then test accuracy is improved, but device complexity increases
Solution Approach 1:
The patent incorporates sealing means (such as O-rings or gaskets) that are pre-installed on the chamber walls before the ring specimen is placed. This preliminary sealing action ensures correct assembly and proper isolation of the internal and external surfaces of the ring, improving test accuracy without requiring complex assembly procedures during the actual testing process.
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 improves the accuracy of external pressure collapse tests, enabling more precise optimization of pipe design, particularly pipe wall thickness, and reduces the need for expensive full-scale pipe tests, facilitating safer and more cost-effective deep-water pipeline installations.
Implementation Method 1
a hydraulic ram for applying a force against the inner surface of the ring when received in the chamber
Implementation Method 2
a fluid inlet port in one of the chamber sections to allow a pressured fluid to be admitted to the chamber outside the ring
Implementation Method 3
at least one sensor for measuring strain and deformation of the ring
Data Source
AI summary
A method and apparatus for testing rings cut from pipes for use in making subsea pipelines are described. The method for determining the whether a test ring is correctly assembled in a test chamber for testing pipes for use in making subsea pipelines comprises: mounting a test ring in a pressure chamber such that the ends of the test ring forms seals with opposing surfaces of the chamber to isolate the inside of the test ring from the outside; providing means for measuring the displacement of the test ring; providing means for measuring a force applied to the inner surface of the test ring; applying a force to the inner surface of the test ring; and using the displacement measurement and force measurements to determine whether the test ring is correctly mounted in the pressure chamber.