Ductile Iron Flange / Backing Ring

Ductile Iron Flanges/Backing Rings are key components widely used in pipe connections. They are commonly used to connect pipes, valves, pumps, and other equipment, ensuring reliable sealing while withstanding certain pressure and mechanical stresses. Made of ductile iron and painted red, these flanges are commonly used in fire protection, water supply and drainage, and industrial fluid transportation.

Product Materials and Construction

Ductile iron is a type of cast iron produced through a spheroidizing process to produce spherical graphite. Compared to gray cast iron, it offers higher strength and toughness, approaching the performance of steel. Flanges or backing rings made of ductile iron ensure high strength and pressure resistance while also offering excellent processability and corrosion resistance.

Backing rings are commonly used with PE, PVC, HDPE plastic pipes to enhance connection strength and ensure a tight seal. Their inner hole is compatible with flange adapters, which are then bolted together to create a stable pipe connection.

Key Features

High Strength: Ductile iron boasts a strength exceeding 400 MPa, capable of withstanding high pipeline pressures.

Good Toughness: Compared to ordinary gray cast iron, it is less susceptible to brittle cracking, making it safer and more reliable.

Corrosion Resistance: Surface treatment typically includes epoxy resin spraying or red anti-rust paint, providing resistance to humid environments and chemical corrosion.

Reliable Sealing: Combined with sealing gaskets and bolts, these connections ensure leak-free pipe connections.

Easy Installation: Simple construction allows for easy installation and disassembly, reducing construction costs.

Wide Application: Suitable for connection to steel, HDPE, PVC, and other pipe materials.

Ductile Iron Flange / Backing Ring Applications

Fire Protection Systems: Red-painted Ductile Iron Flange / Backing Rings are commonly used for fire hydrants, sprinkler systems, and fire protection piping connections, complying with international fire protection pipe network standards.

Municipal Water Supply and Drainage: Widely used in tap water networks, sewage treatment plants, and drainage systems, ensuring stable water supply and drainage operations.

Industrial Piping: Suitable for fluid transportation in the petroleum, chemical, power, metallurgy, and other industries.

Agricultural Irrigation: Used in conjunction with PVC or HDPE pipes, they provide a reliable water supply for large-scale farmland irrigation systems.

Seawater and Freshwater Engineering: With excellent corrosion resistance, they are suitable for use in projects such as ports and marine aquaculture.

Common Standards and Sizes

To meet diverse market demands, Ductile Iron Flanges/Backing Rings are typically manufactured in accordance with the following international standards:

ANSI/ASME B16.5 (American Standard)

DIN 2501/EN 1092-2 (European Standard)

BS 4504 (British Standard)

ISO 7005 (International Standard)

JIS B2220 (Japanese Standard)

Sizes generally range from 1″ to 24″, with common pressure ratings such as PN10, PN16, and PN25. Customers can select the appropriate flange model based on pipe diameter, operating pressure, and specific operating conditions.

Ductile Iron Flange / Backing Ring Production Process

Ductile Iron Flange / Backing Rings are typically sand-cast, poured at high temperatures, annealed, and machined. Finally, they are sandblasted and coated with epoxy or anti-rust paint to ensure a smooth, uniform surface, corrosion resistance, and durability. Rigorous quality inspections include dimensional, strength, sealing, and coating adhesion testing to ensure product performance meets international standards.

Advantages and Value

High Cost-Effectiveness: Compared to carbon steel and steel flanges, they offer superior strength and durability for most applications.

Durability: They maintain excellent performance over time, even in outdoor and humid environments.

Wide Compatibility: They can be used with a variety of pipes and fittings to meet diverse project requirements.

High International Market Acceptance: Complying with multiple international standards, they are widely exported to markets in the Americas, Europe, the Middle East, and Southeast Asia.

Ductile Iron Flange / Backing Rings are high-strength, highly reliable, and corrosion-resistant pipe connection components, widely used in fire protection, municipal water supply and drainage, industrial, agricultural, and marine engineering applications. With its excellent performance, reasonable price and wide applicability, it has become an indispensable and important part of the global pipeline system.