Filter Endcap Sealing Geometry for Leak-Resistant Tubesheet Fit

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Solution Overview

Problem

Existing filter assemblies face challenges in ensuring a secure and leak-proof seal between the endcap and the tubesheet, which can lead to fluid bypass and dislodging during system operation, particularly in filtration systems.

Innovation Solution

The filter assembly incorporates a perimetric sealing surface on the endcap with alternating inward and outward projections and recesses, designed to mate with corresponding filter openings in the tubesheet, enhancing structural rigidity and forming a fluidic seal to prevent leakage and dislodging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a simple endcap design is used, then manufacturing cost is reduced, but sealing reliability deteriorates leading to fluid bypass

Engineering Contradiction:
Improvemanufacturing costVSAvoidsealing reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The endcap is segmented into multiple functional zones: a peripheral sealing surface with alternating projections and recesses for fluidic sealing, and a central portion for structural support. This segmentation allows each zone to perform its specific function optimally, achieving reliable sealing without excessive complexity in the entire endcap structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The endcap features local quality variations through alternating projections and recesses around its periphery. These localized structural variations create complementary mating features with the tubesheet that provide fluidic sealing at specific locations without requiring the entire endcap structure to be complex.

Inventive Principle:
Principle #3Local quality

2Device complexity

If a simple endcap design is used, then device complexity is reduced, but structural rigidity deteriorates leading to dislodging

Engineering Contradiction:
Improveendcap structure complexityVSAvoidstructural rigidity
Core Design Contradiction:
Device complexityVSStability of the object's composition

Solution Approach 1:

The endcap structure is divided into a peripheral sealing portion with projections and recesses, and a central structural portion. This segmentation allows the peripheral zone to provide sealing functionality while the central zone maintains structural rigidity, achieving both goals without requiring the entire endcap to be overly complex or bulky.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The endcap merges multiple functions into a single integrated component: sealing surfaces, structural support, and fluid distribution features are combined in one piece. This integration reduces the number of separate parts and assembly steps, lowering device complexity while maintaining the structural rigidity needed to prevent dislodging.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of manufacture

If a simple endcap design is used, then ease of manufacture is improved, but fluidic sealing deteriorates leading to leakage

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidfluid leakage
Core Design Contradiction:
Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The sealing function is segmented into multiple discrete projection and recess features around the endcap periphery. Each projection-recess pair creates a localized sealing zone, providing redundant sealing paths that prevent fluid leakage without requiring an overly complex manufacturing process.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The endcap incorporates local quality variations through strategically placed projections and recesses at specific locations around its periphery. These localized features create complementary mating surfaces with the tubesheet that establish fluidic sealing at critical locations, preventing leakage while keeping the overall manufacturing process relatively simple.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4397390B1Filter assembly and system
Publication Date: 2026.01.28 DONALDSON CO INC
  • EP4397390B1 patent drawingFigure 1
  • EP4397390B1 patent drawingFigure 2
  • EP4397390B1 patent drawingFigure 3

AI summary

The technology disclosed herein relates to, in part, a filter assembly. Filter media is arranged about a central media opening, where the filter media has a first end and a second end. The central media opening extends in an axial direction from the first end towards the second end. An endcap is coupled to the first end of the filter media. The endcap defines an opening in fluid communication with the central media opening, an inner surface abutting and surrounding the endcap opening, and a perimetric sealing surface about the endcap. A first portion of the perimetric sealing surface projects inwardly towards the endcap opening and a second portion of the perimetric sealing surface projects outwardly from the endcap opening. The first portion and the second portion are in axial alignment, and the perimetric sealing surface forms an oblong loop in a first cross-section orthogonal to the axial direction.