Sealed Pipe Joint with Spacer and Coating Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing pipe string systems face challenges in achieving tight seals between steel pipe sections without high precision manufacturing, which is costly, and are prone to corrosion and fracture due to the use of corrosive fluids and high seawater pressures.
Innovation Solution
The solution involves creating a corrosion-resistant pipe string with threaded joints that include a ring-shaped spacer to ensure precise sealing, corrosion-resistant cladding on the inside surfaces, and knurling on the threads to prevent loosening, along with a design that minimizes coating application and reduces stress on the pipe ends by using a combination of sharp and rounded corners and moderate radii of curvature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high precision manufacturing is used to achieve tight seals between pipe sections, then sealing reliability is improved, but manufacturing cost increases prohibitively
Solution Approach 1:
A spacer element is introduced as an intermediary component between the two pipe sections. The spacer has a first end that abuts the first sealing surface and a second end that abuts the second sealing surface, thereby ensuring proper spacing and sealing without requiring high precision manufacturing of the pipe sections themselves. This mediator component absorbs the dimensional tolerances that would otherwise require expensive precision machining.
2Object-affected harmful factors
If coating is extended around rounded corners to protect against corrosion, then corrosion resistance is improved, but coating application cost and complexity increase
Solution Approach 1:
The sealing surfaces are designed with rounded corners having a specific radius of curvature. This curvature allows the coating to be applied in a controlled manner around the corner without creating sharp angles that would increase coating complexity. The rounded geometry naturally facilitates uniform coating application while maintaining corrosion protection.
3Strength
If tongue and groove joints are used to connect pipe sections, then structural strength is improved, but fracture risk at the groove increases
Solution Approach 1:
The groove is designed with a rounded bottom having a specific radius of curvature, and the tongue is given a complementary rounded end. This curved geometry eliminates sharp corners and stress concentration points in the groove area, significantly reducing the risk of fracture initiation while maintaining the structural strength of the tongue and groove connection.
4Ease of operation
If threaded connections are used to join pipe sections, then assembly ease is improved, but thread loosening due to rotation occurs
Solution Approach 1:
Knurling is applied locally to specific portions of the threads rather than the entire thread structure. This localized surface treatment creates ridges on the thread flanks that increase friction and resistance to loosening, while maintaining the overall threaded connection design for ease of assembly. The knurling is applied only where needed to prevent rotation and loosening.
Data Source
AI summary
In a pipe joint where two pipe sections (14, 16) have threadably engaged end portions (17, 18), joint ends (32, 34) are substantially sealed to each other by a sealing surface (40, 50) on one pipe section that substantially abuts a sealing surface (42, 52) on the other pipe section. In one joint, a ring-shaped cutout (121, FIG. 7) is formed in a first pipe section and a ring-shaped spacer (120) is located in the cutout. The spacer is chosen from several that have slightly different lengths so the spacer end contacts the corresponding sealing surface (130). In a pipe string used to carry corrosive fluid, the inner surface (44) of adjacent pipe sections is covered with a corrosion resistant coating (70, 72). Where the sealing surface is connected to a rounded corner (82, 84), the coating extends to and along the sealing surfaces (40, 42). Where there are sharp corners (80) at the intersection of the inside surface (40) with the sealing surface (40B, 42B), the coating does not extend along the sealing surfaces.