ASTM B395/ ASME SB395 C68700 U Bend Copper & Copper Alloy Tube For Heat Exchanger

Copper and copper alloy U-bends are widely used in heat exchangers, condensers and cooling systems

Pure copper (UNS C12200/C10200)
Excellent thermal/electrical conductivity (thermal conductivity ~400 W/m·K).
Resistant to oxidizing acids (such as dilute sulfuric acid) and non-oxidizing environments.

Aluminum brass (UNS C68700)
Composition: Cu-Zn-Al (aluminum 1.5-2.5%).
Excellent resistance to seawater dezincification corrosion (Dezincification).
Inhibits biofouling and is suitable for marine environments.

Navy brass (UNS C44300/C44400)
Composition: Cu-Zn-Sn (tin 0.8-1.2%) + trace arsenic/antimony.
Resistant to seawater corrosion and better erosion resistance than pure copper.
Lower cost than copper-nickel alloy.

Copper-nickel alloy (e.g. C70600 90/10, C71500 70/30)
Composition: Cu-Ni-Fe (C70600: Ni 10%, Fe 1.5%).
Resistant to high-speed seawater erosion (≤4 m/s) and hydrogen sulfide corrosion.
Anti-biological fouling, high strength (tensile strength ~450 MPa).

Phosphor bronze (UNS C51000)
Composition: Cu-Sn-P (tin 5%, phosphorus 0.1-0.3%).
High strength, fatigue resistance, suitable for vibration environment.
Resistant to seawater and alkaline media.

Description

Corrosion Resistance:
Superior resistance to seawater, biofouling, and dezincification due to aluminum content.
Outperforms plain brass in saline and brackish environments.
Thermal Conductivity: High heat transfer efficiency for condenser/heat-exchanger systems.
Formability: U-bend geometry allows compact design in heat exchangers; annealed tubes resist cracking during bending.

Industry Application

Shipping and marine engineering Seawater condenser, cooler U-tube bundle High salt spray, biofouling, long-term immersion

Thermal/nuclear power plant Steam surface condenser, feedwater heater High temperature steam, circulating cooling water

Desalination plant Multistage flash (MSF) evaporator tube High temperature, high salt, chloride ion corrosion

Chemical equipment Acid-base medium heat exchanger (non-strong oxidizing environment) Medium and low concentration corrosive fluids