ASME SB111 C68700 Heat Exchanger Tube For Marine Engines

ASME SB111 C68700 seamless tube is a copper alloy specifically engineered for high-velocity seawater service. With 1.8–2.5 % Al and trace As, it resists dezincification and impingement attack at flow velocities up to 3–4 m/s, making it the first-choice material for charge-air coolers, oil coolers and jacket-water coolers on marine diesel and gas-turbine engines.

On board main and auxiliary engines, C68700 tubes—supplied as straight or U-coils Ø6–110 mm × 0.5–3 mm wall—are fitted to plate-type or shell-and-tube coolers. A thermal conductivity of 109 W/(m·K) (three times that of stainless steel) removes piston-jacket heat quickly while keeping the cooler compact, and the annealed condition (UTS 360 MPa, El. 50 %) offers high resistance to vibration and thermal fatigue, greatly reducing leakage caused by high-velocity impingement or start-stop thermal cycling.

In addition, the alloy’s inherent bio-fouling resistance lengthens the interval between cleanings, and its excellent cold-bendability and weldability simplify on-board installation and replacement, meeting rules of IMO, LR and DNV. With more than 15 years of documented service life, ASME SB111 C68700 tubing has become a key enabler for ocean-going merchant, container and naval vessels to achieve long-voyage, low-maintenance and high-reliability engine cooling.