Marine Flange Castings | Foundry | Exporter

Flanges are the core connectors of ship pipelines. Ships rely on them to achieve stable connection of pipelines. QD is a reliable partner in the field of marine flange castings.

Core functions of marine flanges

Flanges are detachable components used to connect pipes, valves, pumps and other equipment in ship piping systems. Their main functions include:

• Sealed connection: Bolt fastening makes the pipe interface fit tightly. Prevent leakage of seawater, fuel oil, steam and other media.
• Bearing pressure: Withstand the pressure shock of the medium in the pipeline. Maintain the stability of the connection under the conditions of ship turbulence and vibration.
• Simplified maintenance: The detachable design facilitates pipeline maintenance and replacement of components. Reduce ship downtime.
• Adapt to multiple systems: Adapt to different systems of the ship such as cooling, lubrication, hydraulics, exhaust, etc. Meet the needs of diversified media transmission.

Common materials for flange castings

Flanges need to withstand seawater corrosion, high temperature and pressure, and vibration shock. So, material selection is crucial. The following are common materials and their characteristics:

Material Type	Typical grades	Core Advantages	Applicable scenarios
Carbon Steel	Q235b	Good plasticity and toughness. Good weldability. Easy to process	Fresh water pipeline. Low pressure fuel system
Stainless Steel	304L	Atmospheric corrosion resistance. Oxidation resistance. Excellent toughness	Above deck piping. Fresh water cooling system
	316L	Strong seawater corrosion resistance. Good welding performance	Seawater cooling system. Desulfurization tower pipeline
Alloy Steel	35CrMoV	High strength. Good impact resistance	High-pressure hydraulic systems. High-pressure valve components
Copper Alloy	ZCuAl8Mn13Fe3Ni2	High corrosion fatigue strength. Good casting performance	Marine air conditioning system. High pressure valve body
Duplex Steel	2205	High strength and corrosion resistance. Resistant to stress corrosion cracking	Deep sea exploration equipment pipelines. High salt fog environment

Note: Common materials not listed in the table include: cast iron, cast steel, etc.

QD recommends the most suitable material solution for customers based on the media type, pressure level and environmental conditions. Ensure that the flange is stable and reliable during long-term navigation.

Lost foam casting process

Lost foam casting is suitable for castings with complex structures and high dimensional accuracy requirements. QD’s lost foam casting process has the following characteristics:

• High dimensional accuracy: The dimensional tolerance of castings can reach CT7-CT8 level. Surface roughness Ra≤12.5μm. Reduce the amount of subsequent processing.
• Large design freedom: Flanges with complex inner cavities and special-shaped structures can be cast. No need to split parts. Improve overall strength.
• Wide material adaptability: Compatible with various materials such as carbon steel, stainless steel, alloy steel, etc. Meet the needs of different ship systems.
• High production efficiency: High mold reuse rate. Strong batch production stability. Shorten delivery cycle.

QD lost foam casting production process:

1. Make a foam model: Make a polystyrene foam mold according to the flange size. Combine into a module.
2. Apply paint: Apply refractory paint on the surface of the foam mold. After drying, a protective layer is formed;
3. Modeling and pouring: Put the module into the sand box. Fill with dry sand and vibrate to compact. Pour the molten metal directly. The foam mold vaporizes and disappears.
4. Sand removal and cleaning: Remove the molding sand after cooling. Get the flange blank.
5. Inspection and processing: Through spectral analysis, water pressure test and other inspections. Machining as needed.

QD’s customized services and post-processing capabilities

Ship flanges need to adapt to different ship types (such as bulk carriers, container ships, yachts) and system requirements. Standardized products are difficult to meet all scenarios. QD provides full-process customization services:

• Flexible adaptation: Supports customization of flange size, pressure level (such as PN16, PN40), and sealing surface type (raised face, concave-convex face, tongue-and-groove face) according to drawings.
• Small batch customization friendly: No high mold fees are required. The minimum order quantity can be as low as 50 pieces. Meet the small batch needs of ship repair and modification.
• One-stop service: From material selection, structure optimization, mold design to finished product delivery. Dedicated personnel throughout the process. Reduce communication costs.

Perfect post-processing capabilities:

QD also provides a full range of post-processing services. Improve the performance and aesthetics of flange castings:

• Stainless steel flanges: Through electrolytic polishing and mirror polishing. Improve surface finish and enhance corrosion resistance.
• Carbon steel flanges: Galvanized and painted to form a protective film. Adapt to humid environments.
• High-precision parts: Fine-finished by CNC lathes. Ensure the flatness of the flange sealing surface.
• Special demand processing: For deep-sea equipment flanges, nitriding treatment is provided to enhance surface hardness.

Collaboration with QD

1. Professional experience: More than 20 years of experience in the production of ship hardware castings. Served many domestic and foreign ship companies and shipyards. Familiar with the technical standards of various ship flanges (such as GB, ANSI, DIN).
2. Physical factory guarantee: Own 2 self-owned factories and 2 cooperative factories. Equipped with advanced production equipment and multiple production lines. Can directly control production quality and delivery time.
3. Full process coverage: In addition to lost foam casting, it also masters investment casting, sand casting and other processes. The optimal process can be selected according to the structural characteristics of the flange. Reduce production costs.

QD supplies high quality flange castings to the global marine industry. Whether you require a standardized product or a customized solution, QD can meet your needs.