The 90/10 copper-nickel alloy (UNS C70600) is the most widely used corrosion-resistant piping material in marine engineering and shipbuilding. As the critical connection points within seawater piping systems, these fittings directly determine the operational reliability and service life of the entire piping network. As a professional manufacturer of copper-nickel pipe fittings, Haomei Aluminum offers a comprehensive range of CuNi 90/10 butt-weld fittings and flanges. Both raw materials and finished product dimensions adhere to international standards, meeting the procurement requirements for seawater piping projects in global shipbuilding, offshore platforms, and coastal power plants.

Pipe Fittings Categories and Specifications

CuNi 90/10 pipe fittings cover all connection requirements for piping systems, forming a complete product portfolio.

The CuNi 90/10 elbow category includes 90° long-radius elbows, 45° elbows, and 180° U-bends; custom angles—such as 30° or 60°—are also available to accommodate specific directional changes or spatial constraints.

CuNi 90/10 tee offerings include both equal tees and reducing tees, facilitating efficient flow distribution and branching throughout the piping system.

CuNi 90/10 reducers include both concentric and eccentric types, facilitating a smooth transition between pipes of different diameters.

The CuNi 90/10 fittings also encompasses end caps, lap-joint stub ends, and copper-nickel flanges (including plate-type and weld-neck types), enabling a fully integrated piping system—pipes, fittings, and flanges—made from the same material.

All fittings are available in sizes ranging from DN15 to DN300 (NPS 1/2" to NPS 12") with wall thickness options including SCH40, SCH80, and custom specifications.

Dimensional tolerances strictly adhere to the ASME B16.9 standard for factory-made wrought butt-welding fittings, while raw materials comply with the ASTM B466 specification for seamless copper-nickel alloy pipes.

Key Advantages in Product Quality

All CuNi 90/10 pipe fittings are manufactured from seamless pipe blanks sourced from the same heat, ensuring precise control over chemical composition: 9.0%–11.0% nickel, 1.0%–1.8% iron, ≤1.0% manganese, with copper as the balance; impurity elements such as lead and zinc are strictly maintained below the maximum allowable limits.

In terms of forming processes, elbows are produced via medium-frequency hot-pushing, while tees are manufactured using hydraulic bulging combined with hot-pressing reinforcement. This ensures a continuous and intact metal grain flow; wall thinning on the extrados (outer arc) of elbows is kept within 10%, and the pressure-bearing capacity at the branch-main pipe junction is at least equal to that of the main pipe.

In the annealed state, the finished products exhibit a tensile strength of ≥275 MPa, a yield strength of ≥105 MPa, and an elongation of ≥30%. They offer excellent weldability, allowing for high-quality fusion welding with pipes of the same material during on-site installation.

In seawater environments, the surfaces of 90/10 copper nickel pipe fittings spontaneously form a dense passivation film, resulting in an annual corrosion rate of less than 0.02 mm under standard flow velocities. Furthermore, the material possesses inherent anti-fouling properties against marine organisms, ensuring a stable internal diameter during long-term operation, with a designed service life of over 20 years.

Quality Certification and Factory-Level Control

Haomei CuNi 90/10 pipe fittings has received factory approval from major classification societies, including DNV, ABS, and CCS, with full traceability maintained throughout the entire production process. Every batch undergoes rigorous quality inspections prior to dispatch—including spectral analysis of chemical composition, dimensional tolerance checks, liquid penetrant testing, and hydrostatic testing. For critical orders, additional services such as intergranular corrosion testing and third-party witnessed inspections are available. We provide EN 10204 3.1 mill test certificates for our products, with 3.2-level certificates available for third-party inspected items—fully meeting the requirements for marine vessel classification and offshore project acceptance.

Leveraging extensive experience in export supply, we offer integrated packages of CuNi 90/10 pipes and fittings from a single manufacturer. This ensures material consistency and optimal weld compatibility from the source, effectively eliminating the risk of galvanic corrosion that can arise from combining dissimilar materials. Haomei Aluminum provides a one-stop solution for copper-nickel piping systems; we maintain a ready stock of standard specifications and can accommodate everything from small-scale sample orders to full-container shipments, meeting the seawater piping system procurement needs of clients worldwide.