AISI 4130 API 6A 5K Flange Forging

Description

Forged Flanges Description and Product Overview

TIPTOP produces forged flanges using high-quality raw materials and advanced forging processes, including open die forging and closed die forging. These forged steel flanges are primarily used as high-strength, pressure-bearing sealing connectors in oil and gas wellhead systems.

API 6A wellhead forged flange products, such as AISI 4130 carbon steel forged flanges, are designed to connect critical equipment including casing heads, tubing heads, blowout preventers (BOP), Christmas trees, tees, and manifolds. They are not simply pipe connectors, but essential pressure boundary components that ensure sealing integrity and structural reliability under extreme pressure, effectively preventing blowouts and leakage accidents.

As a typical forging a flange application, forged construction provides superior grain flow, strength, and fatigue resistance compared with cast products, making forged carbon steel flanges the preferred solution for API 6A 5K wellhead service.

Classification of API 6A Forged Steel Flanges

TIPTOP steel forged flanges are classified according to material grade and service environment in compliance with API 6A requirements.

Classification by material performance grade:

The API 6A standard defines several material grades to match different operating conditions:

BB Grade – General service conditions
Representative material: ASTM A105 (carbon steel forged flanges)

DD Grade – Low-temperature service conditions
Representative material: ASTM A350 LF2 (low-temperature carbon-manganese steel)

EE Grade – High-strength service conditions
Representative materials: ASTM A182 F6a, F22, or high-strength low-alloy steels such as AISI 4130

FF Grade – Corrosion-resistant service conditions
Representative materials: ASTM A182 F316, F51 (2205 duplex stainless steel)

HH Grade – Sour service / H₂S environments
Representative materials include enhanced F22, super duplex stainless steels (F55, F61), or nickel-based alloys

Classification by forged flange structure type:

Blind flange

Weld neck flange

Socket weld flange

Threaded flange

Clamp connection hub / end

These configurations cover the majority of API 6A forged flanges used in wellhead and manifold systems.

Applications of Forged Carbon Steel Flanges

TIPTOP forged carbon steel flanges, including AISI 4130 API 6A 5K flange forgings, are widely used throughout the oil and gas well lifecycle wherever high-pressure, high-reliability connections are required.

Typical applications include:

Blowout Preventer (BOP) stack connections

Wellhead assemblies, including casing head to tubing head connections

Christmas tree flange connections

Choke and kill manifold systems

Special clamp-type connection components and hubs

These carbon steel forged flanges ensure long-term sealing performance and mechanical integrity under severe pressure and temperature conditions.

FAQ About Forging a Flange

Q1: What are the advantages of forged flanges compared with cast flanges?

For critical applications such as wellheads and high-pressure pipelines, forged flanges offer significantly higher strength, toughness, and reliability due to their refined grain structure and continuous metal flow. While cast flanges may be suitable for low-pressure or complex shapes, forged steel flanges are the mandatory choice for API 6A pressure-containing components.

Q2: What does PSL mean in API 6A forged flange selection?

PSL (Product Specification Level) indicates the strictness of quality control and inspection:

PSL-1: Basic requirements for general service

PSL-2 / PSL-3 / PSL-4: Increasingly stringent requirements, including higher CVN impact values, enhanced NDT, and full traceability

PSL-3 and PSL-4 require Product Verification Testing (PVT), where prototype forged flange products are destructively tested at pressures exceeding rated working pressure.

Q3: Can you manufacture custom forged flanges?

Yes. TIPTOP specializes in custom manufacturing of high-performance forged flanges in accordance with API 6A / ISO 10423 and NACE MR0175. We support customized forging a flange solutions by selecting appropriate material grades (such as AISI 4130), PSL levels, and forging specifications based on actual operating conditions and connection requirements.