Authored by Pankhuri

Manufacturing of Flanges
Manufacturing of Flanges

Understanding the Role of Flanges in Oil and Gas Operations

Flanges play a critical role in maintaining the infrastructure of the oil and gas industry. They are used to seal and connect various valves and pumps along with other components in a piping system. 

One of the key advantages of flanges is their ability to facilitate easy assembly and disassembly of pipeline components. This is particularly important in maintenance and repair activities.

Overall, they provide secure connections, prevent leaks, and ensure the safe and efficient transport of fluids and gases within the infrastructure.


Types of Flanges

Flanges come in various types and designs and the choice of flange type depends on the specific requirements of the application.

Weld-Neck Flange

This variety of flanges are used in high pressure environments and are suited to be used in repeat bending conditions.These flanges are designed to withstand elevated temperatures and maintain their structural integrity, making them suitable for high-temperature applications in refineries and processing facilities.

Weld neck flanges are connected to pipes by welding them together. Stainless steel, known for its good welding properties, is commonly used for making these flanges. They help reduce stress concentration and transfer stress from the flange to the pipe.

Interconnecting Pipes with Flanges
Interconnecting Pipes with Flanges

Slip-On Flange

Slip-on flanges are extremely common due to their cost effective nature. These flanges are designed to easily slide over the pipe, allowing for a simple and quick installation process.

The flange is typically welded both on the inside and outside to ensure a secure connection. They are typically designed for low-pressure and low temperature processes.

Lap Joint

A lap joint flange is used when space is limited when there is a need to dismantle pipes often. It has two parts: a stub end that’s welded to the pipe, and a separate backing flange that slides over the pipe.

The backing flange doesn’t touch the inside of the pipes, so it can be made from less expensive, tough materials like carbon steel, which can handle some corrosion. But the stub ends, the parts that touch the contents of the pipes, should be made from materials that resist corrosion well and have strong mechanical properties.

Large size flanges adjusted for leakage prevention
Large size flanges adjusted for leakage prevention

Threaded Flange

Threaded flanges are handy in situations requiring swift solutions. They come with threaded holes for easy and speedy attachment.

This threading mechanism enables the flange to be screwed onto the pipe, creating a tight and sealed connection.They are commonly found in systems where pipes transport water or air. Threaded flanges work best in situations with low pressure and moderate temperatures.

Blind Flange

Blind flanges are designed to block or “blind” the end of a pipeline, vessel, or equipment nozzle. These flanges have no openings or bores, meaning they completely seal the pipeline or vessel they are attached to.

They are useful when it comes to isolate sections of a pipeline or equipment during maintenance or repair, preventing the flow of fluids or gases.

Socket Weld Flange

Socket weld flanges are good for lower pressure and temperature situations. They’re attached to pipes by welding them on the outside. These are best for small pipes, but sometimes not ideal due to corrosion issues in some processes.

Manufacturing Flanges to Perfection 

Initial Steps:

  • Blanking
  • Machining
  • Drilling
  • Finishing

Production processes used:


The forging process typically involves several key steps, including selecting a standard steel billet, heating, shaping, and cooling. Forging methods encompass free forging, die forging, and ring forging. These techniques differ in terms of the quantity of forged components produced in each batch. Free forging is suitable for manufacturing basic components and sections in smaller quantities. It offers advantages such as high efficiency, rapid processing, ease of machining, and automation. Die forging, on the other hand, is characterised by higher production volumes, reduced machining requirements, and optimal material distribution, which enhances the durability of the components and extends their service life.


Casting is a process involving the pouring of molten metal into a specially designed cavity that matches the desired flange shape. Once the molten metal cools and solidifies, it takes on the shape of the flange. Most casting materials start as solid but are heated to a liquid state.The mould itself can be made from various materials, including sand, metal, or even ceramics.


The cutting process involves creating flanges by cutting a round plate with the desired inner diameter, outer diameter, and thickness directly from a middle plate. Subsequent steps include processing bolt holes and water lines. The size of these flanges is constrained by the width of the middle plate.

Flange Production
Flange Production


The method of cutting strips from a middle plate and subsequently rolling them into a circular shape is known as rolling. This technique is primarily employed in the production of larger flanges. Following the rolling process, the flanges undergo welding, flattening, and the addition of water lines and bolt holes.

Materials Matter: Choosing the Right Flange Material

  • Steel is the most prevalent material for flanges, appreciated for its high strength in demanding applications. 
  • Stainless steel, on the other hand, excels in scenarios where durability and resistance to corrosion are essential. 
  • Aluminium flanges find their niche in applications where both corrosion resistance and a lightweight structure are vital, such as in irrigation systems. 
  • Ductile iron is a cost-effective alternative to steel, boasting a higher yield strength. It’s especially favoured when the flange doesn’t directly interact with the medium, like in backing flanges, where cost-efficiency takes precedence.
Flanges fastened to seal pipeline
Flanges fastened to seal pipeline

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Our extensive, cutting-edge solutions offer manufacturing services that encompass CNC machining, 3D printing, Sheet metal fabrication, Injection moulding, and Vacuum casting.

If you’re looking for a manufacturer of flanges that meets the technical capabilities whilst incorporating quality control systems, contact us today! Optimise your operations with‘s expertise in manufacturing high performance components that meet industry standards.

Let us help you reach the optimal outcome for all your manufacturing requirements. To get started, simply email Alay Shah on with your specifications or fill out the form below.