Overboard Discharge Pipe Insert Assembly for Corrosion Repair
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Marine vessels' overboard discharge pipework is prone to corrosion from acidic washwater, leading to costly and time-consuming repairs, especially in scrubber outlet assemblies where corrosion-resistant coatings can be incomplete or fail due to galvanic corrosion between dissimilar materials.
Innovation Solution
A method involving a tubular insert with adhesive and/or chocking material is used to secure the insert within the overboard discharge pipe, providing a reliable bond and alignment without fasteners, and utilizing corrosion-resistant materials to prevent corrosion, along with a kit of parts for easy installation and repair.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a corrosion-resistant coating is applied to the weld and pipe, then corrosion protection is improved, but coating gaps or weaknesses still expose underlying material to corrosive washwater
Solution Approach 1:
The patent introduces an intermediary corrosion-resistant liner or sleeve that is inserted into the discharge pipe and welded to the hull. This intermediary component provides a continuous corrosion barrier between the corrosive washwater and the underlying steel structures, eliminating the need for imperfect surface coatings on complex weld geometries.
Solution Approach 2:
The patent uses homogeneous corrosion-resistant materials (such as stainless steel or corrosion-resistant alloy) for the liner/sleeve that are continuously welded or bonded to create a uniform, gap-free corrosion barrier, eliminating the heterogeneous and discontinuous protection provided by sprayed or dipped coatings.
2Reliability
If dissimilar materials (stainless steel pipe and mild steel hull) are used, then corrosion resistance is improved, but galvanic corrosion occurs at the interface
Solution Approach 1:
The patent introduces an intermediary component (liner or sleeve) made of corrosion-resistant material that is continuously connected to the hull structure, acting as a mediator that prevents direct galvanic contact between dissimilar materials while maintaining corrosion resistance.
Solution Approach 2:
The patent employs homogeneous material construction for the intermediary liner/sleeve that eliminates material discontinuities and galvanic couples, creating a uniform corrosion barrier that prevents galvanic corrosion mechanisms.
3Ease of repair
If repair involves replacing sections of assembly or pipe, then corrosion damage is addressed, but dry-docking is required which is costly and time-consuming
Solution Approach 1:
The patent segments the corrosion protection function from the structural pipe function by introducing a separate, replaceable liner or sleeve component. This allows the corrosion barrier to be independently repaired or replaced without replacing the entire pipe assembly or requiring dry-docking of the vessel.
Solution Approach 2:
The patent employs a disposable or easily replaceable liner/sleeve that can be quickly installed or replaced as a consumable corrosion barrier, eliminating the need for expensive and time-consuming structural pipe replacement or dry-docking operations.
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 effectively reduces corrosion risks and simplifies repairs by ensuring a secure, corrosion-resistant bond between the tubular insert and the pipe, allowing for quicker return to service without the need for dry-docking, while addressing galvanic corrosion concerns.
Implementation Method 1
providing in the space an adhesive and/or chocking material for adhering and/or chocking the tubular insert in the overboard discharge pipe
Data Source
AI summary
Disclosed is a method (200) of assembling a vessel overboard discharge assembly (600), the method (200) comprising: inserting (210) a tubular insert (500) into an overboard discharge pipe (300) so that a space (400) is defined between the tubular insert (500) and the overboard discharge pipe (300): blocking (221) an outboard opening (401) into the space (400) at an outboard end (301) of the space (400): and providing (280) in the space (400) an adhesive (450) and/or chocking material (450) for adhering and/or chocking the tubular insert (500) in the overboard discharge pipe (300).