Dual Raised Face Flange Assembly for Lower Bolt Load Sealing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing flanges for nuclear reactor modules face challenges with high bolt tension requirements, large material usage, and undesirably large footprints, exacerbated by rotation and prying issues that lead to leaks, which are not effectively addressed by commercially available tools.
Innovation Solution
A dual raised face self-energizing flange system with offset faces to create a mechanical lever action, reducing bolt loads and stabilizing the joint against rotation, allowing the use of commercially available tensioning tools and achieving a more compact design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a flat face flange is used to provide a leak-free coupling, then the joint can be assembled with simple structure, but high bolt tension is required which leads to overstressing and requires large quantities of bolts and large footprint
Solution Approach 1:
The flange face is segmented into two distinct raised faces at different radial positions (inner and outer), each contributing to seal contact. This segmentation allows the sealing function to be distributed across two surfaces, reducing the burden on individual bolts and enabling lower overall bolt tension while maintaining leak-free coupling.
Solution Approach 2:
The invention transitions from a single-plane sealing surface to a two-plane sealing arrangement with raised faces at different axial positions. This dimensional change creates a mechanical lever action that amplifies the sealing force, allowing reduced bolt tension to achieve the same or better sealing performance compared to conventional flat face flanges.
2Reliability
If the number of bolts is increased to avoid leaks under high pressure, then the leak-free coupling is improved, but the footprint and material usage increase undesirably
Solution Approach 1:
By dividing the sealing function across two raised faces, the system achieves reliable leak-free coupling with fewer bolts. The segmented sealing surfaces create a mechanical advantage that distributes the sealing load more efficiently, reducing the total number of bolts required and consequently reducing the flange footprint.
Solution Approach 2:
The invention changes the geometric parameters of the flange interface by introducing raised faces with specific heights and radial positions. This parameter change creates a mechanical lever action that amplifies sealing force, allowing the same sealing reliability to be achieved with fewer bolts and a smaller overall flange area.
3Reliability
If the flange is stabilized against rotation to prevent leaks, then the seal reliability is improved, but the structure becomes more complex requiring additional stabilization features
Solution Approach 1:
The dual raised faces are positioned asymmetrically at different radial distances from the center, creating an inherent mechanical lever action that provides rotational stability. This asymmetric geometry naturally resists rotation and prying forces without requiring additional stabilization features, maintaining seal reliability while avoiding increased structural complexity.
4Ease of manufacture
If conventional flat face flanges are used, then manufacturing is simple, but bolt loads are too high for commercially available tensioning tools
Solution Approach 1:
By introducing the axial dimension with raised faces at different heights, the invention creates a mechanical lever action that reduces the required bolt load. The manufacturing process remains relatively simple as it involves adding raised surfaces to the flange face, while the bolt load is reduced to levels suitable for commercially available tensioning tools.
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 dual raised face flange system reduces bolt loads by 30-40%, stabilizes the joint against rotation, and ensures a leak-tight seal, enabling a more compact and cost-effective flange configuration.
Implementation Method 1
A dual raised face self-energizing flange system with offset faces to create a mechanical lever action, reducing bolt loads and stabilizing the joint against rotation
Data Source
Figure 1A~1B
Figure 2A
Figure 2B
AI summary
A raised face flange assembly comprises an upper flange (11) to couple to a lower flange (12) using one or more bolts (5): wherein the upper flange (11) or the lower flange (12) comprises: a bolting face (25) defining one or more openings for the one or more bolts (5), respectively; a pair of raised faces (21, 22) including a first raised face and a second raised face to make contact with a mating surface of the other of the upper flange (11) or the lower flange (12); wherein a distance between an area of the second raised face (22) and a plane corresponding to the bolting face (25) is greater than a distance between an area of the first raised face (21) and the plane to distribute contact force with a mating surface over the area of the second raised face (22) to maintain a seal.