Electrical Penetrator Assembly Ceramic Seal Preloading

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Solution Overview

Problem

Existing electrical penetrator assemblies face challenges in creating a robust and reliable seal between a ceramic insulating sleeve and a metal penetrator housing, particularly under high differential pressures and temperature variations, with conventional sealing methods like brazing and welding being inadequate for this application.

Innovation Solution

The use of metal, annular sealing members brazed to the ceramic sleeve assembly, combined with a compression member preloading mechanism, creates a strong seal between the sleeve and the penetrator housing, reducing stress on the sealing members and allowing for a compact design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If conventional sealing methods like brazing and welding are used between ceramic insulating sleeve and metal penetrator housing, then the sealing strength is improved, but the reliability under high differential pressure and temperature variations deteriorates

Engineering Contradiction:
Improvesealing strengthVSAvoidsealing reliability under high pressure and temperature
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

A metal annular sealing member is introduced as an intermediary component between the ceramic insulating sleeve and the metal penetrator housing. This sealing member is brazed to both the ceramic sleeve and the metal housing, creating a reliable seal that accommodates thermal expansion differences and withstands high differential pressures without compromising the integrity of the ceramic-metal interface

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The sealing structure employs a composite design combining ceramic material for the insulating sleeve, metal material for the housing and sealing member, and brazing material to join them. This composite approach leverages the advantages of each material: ceramic provides electrical insulation and high temperature resistance, metal provides mechanical strength and pressure resistance, and brazing provides a reliable bonding interface that accommodates thermal stresses

Inventive Principle:
Principle #40Composite materials

2Reliability

If a robust seal is created between ceramic sleeve and metal housing, then the sealing reliability is improved, but the space required for the seal increases

Engineering Contradiction:
Improvesealing reliabilityVSAvoidspace required for seal
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The metal annular sealing member is designed as a thin-walled structure that provides effective sealing with minimal volume. The sealing member's geometry allows it to deform slightly under pressure to maintain seal integrity, achieving reliable sealing with a compact design that minimizes the space required in the penetrator assembly

Inventive Principle:
Principle #30Flexible shells and thin films

3Strength

If compression member preloading mechanism is used, then the stress on sealing members is reduced, but the device complexity increases

Engineering Contradiction:
Improvestress resistance of sealing membersVSAvoidcomplexity of preloading mechanism
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The compression member is preloaded during assembly to apply a compressive force on the ceramic insulating sleeve and sealing members before the penetrator is installed in service. This preliminary action ensures that the sealing members are under optimal stress conditions from the start, reducing the risk of seal failure under operating pressures without requiring complex active control mechanisms

Inventive Principle:
Principle #10Preliminary action

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 configuration ensures a reliable seal capable of withstanding high differential pressures and temperature extremes while minimizing the space required for the seal, reducing the load on the ceramic sleeve assembly and maintaining structural integrity.

Implementation Method 1

The use of metal, annular sealing members brazed to the ceramic sleeve assembly

Methodology Applied
Scientific EffectBrazing: Brazing

Data Source

PatentEP3114741B1Electrical penetrator assembly
Publication Date: 2019.01.30 FMC TECHNOLOGIES INC
  • EP3114741B1 patent drawingFigure 1~3
  • EP3114741B1 patent drawingFigure 4~6
  • EP3114741B1 patent drawingFigure 7~8

AI summary

A method of manufacturing an electrical penetrator assembly (1) comprising a penetrator housing (3) having a through-bore and an internal support surface; a ceramic sleeve assembly (2) sealing!y providing a feed- through for an electrical conductor (29), which sleeve assembly comprises first and second outer support surfaces; and a compression member (6) comprising a compression surface; said method comprising the steps of sealingly attaching at least one metal, annular sealing member (4, 5) to a section of the sleeve assembly; positioning the sleeve assembly in the through-bore of the penetrator housing such that the first, outer support surface is brought into contact with the internal support surface; attaching the compression member to the penetrator housing such that the compression surface is brought into contact with the second, outer support surface; by means of the compression member, directly or indirectly preloading the sleeve assembly by applying a force onto the sleeve assembly such that a predetermined contact pressure is obtained between the first, outer support surface and the internal support surface; and directly or indirectly, sealingly connecting the at least one sealing member to the penetrator housing. The invention also relates to an electrical penetrator assembly manufactured according to the method.