In a groundbreaking development for advanced engineering sectors, TOBO Industrial Solutions has unveiled a pioneering manufacturing capability: the Factory Customized C71500 (70/30) & A105 Raised Face Weld Neck Flange. This innovative product line represents a sophisticated fusion of materials—pairing the exceptional corrosion resistance of Copper-Nickel 70/30 (CUNi, UNS C71500) with the proven structural strength of ASTM A105 carbon steel forgings. Manufactured under the certified TOBO Brand and backed by ISO 9001 quality management systems, this hybrid flange solution is engineered to address the most demanding challenges in offshore, marine, and chemical processing piping systems .
Material Innovation: The Synergy of C71500 and A105
The core innovation lies in the strategic combination of two distinct materials into a single, optimized component, delivering the "best of both worlds" for critical applications .
C71500 (70/30) Copper-Nickel Hub & Facing: The weld neck and raised face of the flange are constructed from Copper-Nickel 70/30. This alloy, with approximately 70% copper and 30% nickel, offers superior corrosion resistance compared to the more common 90/10 variant, especially in high-velocity seawater, brine, and environments with high sulfide or ammonia content. It provides outstanding resistance to biofouling, erosion-corrosion, and stress-corrosion cracking, making it the premium choice for critical seawater handling .
ASTM A105 Carbon Steel Backing Ring: The outer bolting ring and structural backbone of the flange are forged from ASTM A105 carbon steel. This material provides high tensile strength, excellent machinability, and, crucially, a significant cost advantage over a solid CuNi flange. It is perfectly suited to handle the mechanical bolt loads and structural stresses of the connection .
This bi-metallic design ensures that the process-side faces the corrosive medium with the most resilient material (C71500), while the structural and bolting integrity is managed by a robust, economical, and strong material (A105). The result is a component that offers optimal performance at a significantly lower total cost compared to a solid C71500 flange, without compromising the integrity of the pressure boundary .
Superior Resistance to Corrosion and Seawater
Copper-nickel alloys, especially the 70/30 grade, are renowned for their exceptional performance in saline and brackish water environments. They are specifically engineered to resist biofouling, stress corrosion cracking, and pitting—problems common in offshore and coastal installations .
Key properties of C71500 include :
Outstanding resistance to seawater corrosion and impingement attack
Natural resistance to marine biofouling, reducing maintenance requirements
Excellent resistance to stress-corrosion cracking in chloride environments
Superior thermal and mechanical stability for long-term service
This makes TOBO's hybrid flanges the first choice for critical applications in seawater piping systems on ships and submarines, desalination plants, offshore oil platforms, and cooling systems in power stations and marine engines .
Customization at the Core: The TOBO Factory Advantage
Moving beyond standard catalog dimensions, TOBO's program is built on full factory customization. Clients can specify :
Non-Standard Dimensions: Custom outside diameters, bolt circles, hub thicknesses, and bore sizes to match proprietary equipment or legacy systems
Pressure Class Variations: Engineered to meet specific requirements beyond standard ASME B16.5 classes (e.g., Class 150, 300, 600) for unique project demands
Specialized Fabrication: Integration of specific NDE (Non-Destructive Examination) requirements, unique marking, or heat treatment protocols
Joint Integrity Design: Precise control over the raised face finish (e.g., serrated vs. smooth) to ensure perfect gasket seating for the specific service
All flanges are available with Raised Face (RF), Flat Face (FF), Ring Joint (RJ), and other sealing surfaces depending on the sealing and installation requirements . This is all managed under the TOBO Brand promise, which guarantees strict adherence to material specifications, dimensional accuracy, and performance validation .
Precision Manufacturing and ISO 9001 Certification
All flanges are manufactured at TOBO's ISO 9001:2015-certified facility, where raw materials are forged, heat treated, CNC machined, and tested under strict quality control procedures . The entire manufacturing process, from material sourcing and bonding/cladding technology to final machining and testing, is governed by this certified quality management system .
Key quality features include :
Uniform grain structure through controlled forging
Smooth sealing surfaces to ensure leak-proof assembly
Strict dimensional accuracy per ASME/DIN standards
Hydrostatic and pressure testing upon request
Material test reports (MTRs) , EN 10204 3.1 / 3.2 certifications
The ISO 9001 certification provides clients with absolute assurance of process control, traceability with full Material Test Reports for both the C71500 and A105 materials, inspection rigor including in-process and final inspections, and a systemic approach to continuous improvement .
TOBO also offers third-party inspection by SGS, TUV, BV, or customer-appointed agencies for added confidence on high-value or critical projects .
Target Applications: Solving High-Stakes Engineering Challenges
This hybrid flange is specifically designed for critical interfaces in aggressive environments :
Offshore Oil & Gas: Ideal for topside piping on platforms and FPSOs where seawater cooling lines (CuNi side) connect to carbon steel firewater or utility systems (A105 side). It eliminates the need for a separate, problematic carbon steel-to-CuNi transition weld in the field .
Desalination & Power Plants: Perfect for connecting high-grade CuNi condenser tubing or brine heater piping to carbon steel header systems or pump casings .
Marine & Naval Vessels: For seawater intake and overboard discharge systems, providing a durable, corrosion-resistant connection point at the interface with the ship's steel hull or structural piping .
Chemical Processing: In systems where a specific corrosive process stream in CuNi piping must interface with a carbon steel utility or support system .
Cooling Systems: For power stations, marine engines, and industrial process cooling requiring long-term corrosion resistance .
Market Impact and Industry Validation
"The introduction of a factory-customized, bi-metallic C71500/A105 flange is a game-changer for project engineering," stated a senior materials engineer for a global offshore engineering firm. "It solves a major corrosion management and cost challenge at a single flange face. Instead of specifying an expensive solid CuNi flange or managing the metallurgical complexity of a field weld between dissimilar metals, we can now specify a single, certified, fit-for-purpose component from TOBO. The ISO 9001 certification gives us the documentation and confidence required for class-approved projects" .
This product exemplifies the shift in advanced manufacturing from supplying discrete commodities to delivering engineered application solutions. It reduces total installed cost, mitigates lifecycle corrosion risk, and simplifies procurement and logistics for complex projects .
Sustainable and Recyclable Engineering
Another advantage of copper alloy flanges is their environmental sustainability. Copper and its alloys are 100% recyclable without loss of performance, making them ideal for companies pursuing ESG goals or participating in green building certifications such as LEED or BREEAM .
TOBO's supply chain ensures traceability of raw materials and supports circular economy initiatives. Customers are provided with data on recycled content, energy-efficient manufacturing, and lifecycle performance, helping them meet project-specific compliance and sustainability targets .
Conclusion: Redefining the Interface in Corrosive Service
The launch of the Factory Customized C71500/A105 Raised Face Weld Neck Flange by TOBO represents a significant leap in practical materials engineering. By intelligently combining two world-class materials into a single, customizable, and certified component, TOBO is providing the market with a smarter, more economical, and more reliable solution for one of the most critical points in any piping system: the flange connection .
This innovation empowers engineers to design with greater confidence for harsh environments, ensuring longevity, safety, and performance at the most vulnerable interfaces. It is not merely a new product; it is a new standard for durable connections in the world's most demanding industries .
About TOBO Industrial Solutions:
TOBO is a leader in the design and manufacture of specialized fluid handling components and forged products for critical service in the energy, marine, and chemical sectors. Focused on metallurgical expertise and advanced manufacturing, TOBO provides engineered solutions where standard components fall short. With over 15 years of experience in copper alloy applications, their engineers assist clients in material selection, design optimization, and cost-reduction strategies—making TOBO a valuable partner, not just a supplier .