Marine & Shipbuilding Industry

A double offset (or double eccentric) butterfly valve is a significant advancement over traditional concentric designs. The Koreyda double offset features a disc mounted on a shaft with two offsets:

Axis Offset: The shaft is positioned behind the centerline of the disc seat.

Centerline Offset: The shaft axis is offset from the pipeline centerline.

This ingenious geometry creates a cam-action during the final 10-15 degrees of closure. The disc seals against the seat with a tight, friction-free contact, eliminating wear and ensuring a bubble-tight shut-off even after thousands of cycles. For marine applications, this translates to unparalleled reliability in critical systems, reduced maintenance, and enhanced operational safety.

Key Details & Marine-Specific Features

Superior Sealing & Unidirectional/Bidirectional Capability

Koreyda marine valves are designed to provide bi-directional shut-off (upstream and downstream) or optimized uni-directional flow, depending on the system design (e.g., pump discharge, sea water lines).

Our proprietary seat materials—including durable EPDM, NBR, and high-grade PTFE—are formulated for excellent resistance to saltwater, hydrocarbons, ballast water, chemicals, and fire, complying with marine fire safety standards (e.g., FTP Code).

Robust Construction & Corrosion Defense

Body & Disc Materials: We offer a full range of corrosion-resistant materials including Duplex & Super Duplex Stainless Steel (316, 316L, 2205, 2507), Bronze, and Copper-Nickel (CuNi). All materials are selected for optimal performance in saline and offshore environments.

Advanced Coatings: For added protection in ballast and seawater systems, valves can be supplied with epoxy powder coatings or cathodic protection compatibility in mind.

Shafts: High-strength stainless steel shafts with a secure, anti-blowout design ensure integrity even under high-pressure surges.

Compact, Lightweight Design

The inherent space-saving profile of the butterfly valve is ideal for the cramped engine rooms and piping manifolds aboard ships. Koreyda valves provide a lower weight alternative to gate or globe valves, contributing directly to vessel weight savings and efficiency.

Optimal Flow Characteristics & Low Pressure Drop

The offset disc design minimizes turbulence and provides an excellent flow coefficient (Cv). When fully open, it creates a smooth, low-resistance flow path, which is crucial for pump suction and discharge lines, cooling water systems, and fuel oil transfer lines, reducing pump energy consumption.

Reliable Actuation for All Marine Systems

Valves can be fitted with marine-grade gear operators, pneumatic actuators (with solenoid valves and limit switches), or electric actuators.

All actuation options are available with IP67/IP68 waterproof ratings and certified coatings to withstand constant humidity, salt spray, and vibration.

Easy integration with centralized ship automation and control systems (IAS).

Typical Marine Applications for Koreyda Double Offset Valves

Seawater Cooling Systems: Main & auxiliary engine cooling, HVAC cooling.

Ballast Water Management Systems: Inlet, outlet, and recirculation lines.

Firefighting Systems (F&FF): Pump suction, deluge, and ring main lines.

Fuel Oil & Lubrication Oil Systems: Transfer, service, and return lines.

Bilge & Drain Systems.

Cargo Handling Systems on tankers and specialized vessels.

Fresh Water & Sanitary Systems.

Why Choose Koreyda for Your Marine Valving?

Marine Expertise: We design with the Rules of leading classification societies in mind (ABS, DNV, LR, BV, RINA, etc.) and support type approval processes.

Reliability at Sea: Our valves are built for zero-failure performance, ensuring system availability and crew safety.

Global Service Support: With an understanding of global port logistics, we provide timely technical support and spares service to keep fleets operational.