Forged Steel Flange

Forged steel flange offers higher precision and better performance compared to cast flanges. It is widely used across various industries for connecting pipelines and equipment, especially in high-pressure and high-temperature environments.

Forged flanges are plate-type components, usually circular in shape, that are attached to the ends of pipes, fittings, valves, or other equipment. They facilitate easy assembly and disassembly of piping systems while providing excellent mechanical strength and reliability.

Connection Types:

Slip On Flange

Weld Neck Flange

Blind Flange

Socket Weld Flange

Lap Ring Joint

Threaded Flange

Raw Material for Forged Flange

Forged steel flanges are typically manufactured from pipe billets. The billet is cut and then repeatedly hammered to remove internal defects such as segregation and porosity in the ingot, resulting in a stronger and more reliable structure.

Material Standards

Forged steel flange materials are generally carbon steel, alloy steel, and stainless steel.

Stainless Steel: ASTM A182 F304, F316
Alloy Steel: ASTM A182 F5, F9, F11, F12, F21, F22
Carbon Steel: ASTM A105, ASTM A694 F42, F46, F52, F60, F65, F70, ASTM A350 LF2

ASTM Standards Overview

ASTM A182: Forged alloy & stainless steel piping components for pressure systems (flanges, fittings, valves).
ASTM A105: Carbon steel forged components for ambient and high-temperature pressure systems.
ASTM A350: Carbon and low alloy steel forgings for low-temperature service with notch toughness requirements.
ASTM A694: Carbon and alloy steel forgings for high-pressure transmission service.

Forged Flange Pressure Ratings

Class 150 lb
Class 300 lb
Class 600 lb
Class 900 lb
Class 1500 lb
Class 2500 lb

Advantages of Forged Steel Flange

High pressure resistance
Excellent temperature resistance
Superior durability
Easy installation and maintenance

Manufacturing Process

Forging typically follows these steps:

Selecting high-quality billet
Heating
Forming
Forging
Cooling

Manufacturing Standards Referred

ASME B16.5: Pipe flanges and flanged fittings dimensions
ASME B16.47: Large diameter flanges (NPS 26–60)
MSS-SP44: Steel pipeline flanges
API 605: Large diameter carbon steel flanges

Forging Methods

Forged steel flanges are produced using different forging techniques depending on production volume and quality requirements.

Free Forging

Low productivity but highly flexible, suitable for small batches and simple shapes.

Die Forging

The heated billet is placed into a forging die mounted on equipment, producing more precise and repeatable components.

Forged vs Cast Flange

Cast Iron Flange

Low cost and high production efficiency
Suitable for low/medium pressure systems
Complex shapes possible
May contain defects (porosity, cracks, inclusions)
Lower mechanical strength compared to forged flanges