Pitless Unit Weld Cladding for Corrosion Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Pitless units in pumping systems are prone to corrosion due to their susceptibility to hard water ions and corrosive treated water, leading to premature failure and contamination risks, especially with existing galvanized and epoxy coatings that are prone to chipping and delamination.
Innovation Solution
The use of weld cladding with corrosion-resistant metallic materials like nickel and chromium stainless steel on the wetted surfaces of the connector's housing and spool, providing a chemically fused, continuous corrosion-resistant layer that reduces leaching and enhances structural integrity during installation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If galvanized or epoxy coatings are applied to protect against corrosion, then corrosion protection is improved, but the coating is susceptible to chipping and delamination during installation and service
Solution Approach 1:
The wetted surfaces are prepped through blasting or pickling before applying the corrosion-resistant coating, ensuring proper adhesion and preventing future delamination. This preliminary surface preparation action addresses the root cause of coating failure.
Solution Approach 2:
The patent changes the material parameter from standard galvanized or epoxy coatings to stainless steel cladding material with specific chromium content (10-30%), fundamentally altering the material properties to achieve both corrosion resistance and mechanical integrity.
2Reliability
If epoxy coating is applied to protect against corrosion, then corrosion resistance is improved, but the coating may break or spall during service life if base material is not prepped properly
Solution Approach 1:
The wetted surfaces are prepped through blasting or pickling before applying the corrosion-resistant coating, ensuring proper adhesion and preventing future delamination. This preliminary surface preparation action addresses the root cause of coating failure.
3Reliability
If galvanized coating is applied to protect against corrosion, then initial corrosion protection is improved, but the sacrificial nature limits service life
Solution Approach 1:
The patent changes the material parameter from standard galvanized or epoxy coatings to stainless steel cladding material with specific chromium content (10-30%), fundamentally altering the material properties to achieve both corrosion resistance and mechanical integrity.
4Reliability
If weld cladding with stainless steel is applied to wetted surfaces, then corrosion and erosion resistance is significantly improved, but manufacturing complexity increases
Solution Approach 1:
The patent applies corrosion-resistant stainless steel cladding material specifically to the wetted surfaces (interior surfaces of housing and spool) rather than the entire component. This localized application reduces material costs and manufacturing complexity while maintaining corrosion resistance where it is most needed.
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 weld cladding significantly reduces corrosion and erosion, maintaining water purity and preventing contamination, while being more durable and resistant to damage during installation, thus ensuring longer service life and compliance with drinking water standards.
Implementation Method 1
the inner faces of the first and second end plates and said interior surface of the housing are weld cladded with a metallic cladding material
Data Source
AI summary
There is disclosed a connector which is sometimes referred to as a pitless unit in industry for use in a pumping system including a pump, well casing, a discharge pipe to guide liquid horizontally away from the pump, and a drop pipe to guide the liquid up from the pump towards the discharge pipe. The connector acts to connect the drop pipe and discharge pipe in fluidic communication while allowing the pump there beneath to be accessed from the surface of the ground. The connector features an outer housing and internal spool which is locatable in the housing in a seated position. An interior surface of the housing and surfaces of the spool which collectively define a chamber through which the liquid flows, when the spool is in the seated position, are weld cladded with a metallic cladding material so as to resist corrosion and erosion of these wetted surfaces of the connector.