Insulated Pipe End Sealing Using Jaw Welding

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Solution Overview

Problem

Existing methods for sealing the casing and inner coating of insulated pipes used in offshore oil and gas transportation are inadequate, particularly at high temperatures, leading to seawater infiltration and reduced insulation effectiveness, and require cumbersome processes that disrupt continuous production lines.

Innovation Solution

A method involving the use of a jaw to heat and weld the exposed inner coating sections of insulated pipes, allowing for a continuous process where the casing is extruded over the inner coating, forming a strong seal that withstands high temperatures and external pressures without delamination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If mastic is used as sealant to join casing and inner coating, then sealing effectiveness is improved at limited temperatures, but the seal delaminates and allows seawater infiltration when exposed to high temperatures up to 140°C

Engineering Contradiction:

Improvesealing effectivenessVSAvoidtemperature resistance

Core Design Contradiction:

ReliabilityVSTemperature

Solution Approach 1:

The patent changes the material parameter of the sealant from temperature-sensitive mastic to temperature-resistant foam material that can withstand high temperatures up to 140°C and above, eliminating delamination and seawater infiltration issues

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces expensive and unreliable mastic sealant with a more durable foam material that provides long-term sealing performance under extreme temperature conditions, effectively making the sealant replaceable and reliable

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

2Strength

If electrically conductive welding band is used to seal casing and inner coating, then seal strength is improved, but the production line must be stopped making the process non-continuous

Engineering Contradiction:

Improveseal strengthVSAvoidproduction continuity

Core Design Contradiction:

StrengthVSProductivity

Solution Approach 1:

The patent implements a continuous sealing process where foam material is extruded and expanded in-place to seal the joint between casing and inner coating, eliminating the need to stop the production line for welding operations and maintaining continuous manufacturing flow

Inventive Principle:

Principle #20Continuity of useful action

Solution Approach 2:

The patent replaces the mechanical welding process with a chemical/physical expansion process where foam material expands to create the seal, eliminating the need for electrically conductive welding bands and associated equipment

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If single insulated pipes are used instead of joined pipes, then tightness and insulation integrity are improved, but the complexity of sealing the insulation layer at pipe ends increases

Engineering Contradiction:

Improveinsulation integrityVSAvoidsealing process complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent employs a self-sealing mechanism where foam material is extruded into the joint space between casing and inner coating, automatically expanding to fill gaps and create a tight seal without requiring complex manual sealing operations or additional sealing components

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent applies foam sealing material specifically at the critical joint regions where casing and inner coating meet, providing localized sealing exactly where needed to maintain insulation integrity while simplifying the overall sealing process

Inventive Principle:

Principle #3Local quality

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 method provides a robust, continuous sealing process that maintains insulation integrity at high temperatures and pressures, preventing seawater infiltration and allowing for efficient pipeline operation without the need for mastic or electrically conductive welding bands, thus reducing repair costs and maintaining pipeline functionality.

Implementation Method 1

heating the exposed layer of inner coating (104') using the jaw (204) to a temperature near or above the welding temperature of the materials which the inner coating (104) and a casing layer (108, 110) are made of

Methodology Applied

Scientific EffectHeating: Heating

Implementation Method 2

welding the exposed layer of inner coating (104') and the insulation layer (106) with a layer of casing (108)

Methodology Applied

Scientific EffectWelding: Welding

Data Source

PatentEP3419812B1Method for producing single insulated pipes

Publication Date: 2020.09.23 LOGSTOR

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AI summary

Disclosed herein is a method for producing insulated pipes having an improved protection of the insulation material. The pipe system comprises an inner pipe with a longitudinal axis extending from a first end of the inner pipe to a second end of the inner pipe, the inner pipe comprising a middle section, a first end section at the first end of t he inner pipe, and a second end section at the second end of the inner pipe, a layer of inner coating covering the inner pipe, the layer of inner coating comprising one or more inner coating sub layers, one or more layers of insulation material covering th e layer of inner coating such that the insulation layer covers the middle section of the inner pipe covered by the inner coating, and the ends of the insulation layer tapers towards the end sections, and the end sections comprises a section with an exposed layer of inner coating.