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Flanges Master Guide

Flanges connect pipes, valves, and other equipment in piping systems across various industries. They provide a convenient way to dismantle and reassemble the pipes for maintenance, repair, or modification. Moreover, they help reduce vibration and noise and distribute stress evenly across the joint.

Coastal Flange is a highly respected manufacturer and distributor of pipe flanges, offering a comprehensive range of products from 1/2″ to 200″ OD. We offer various flange types, including weld neck, slip-on, blind, lap joint, threaded, and socket weld flanges. Furthermore, we have state-of-the-art facilities at the heart of the oil, gas, and petrochemical industry in Jersey Village, Texas. This strategic location provides convenient access to rail, truck, air, and water transportation.

This guide will cover everything you need to know about flanges, including their types, welding process, benefits, and the industries that utilize them. We will also discuss the key considerations when choosing flanges for your application.

Types of Flanges

The following are different types of flanges and their uses:

Weld Neck Flange

The weld neck flange is a reliable choice for high-pressure and high-temperature applications due to its long, tapered hub that provides a leak-proof connection.

Slip-On Flange

Slip-on flanges are cost-effective and easy to install but not recommended for high-stress applications.

Blind Flange

Used to close the end of a pipe or valve, blind flanges come in various sizes and materials, providing a secure and leak-proof seal. They are also useful for inspecting and cleaning the piping system.

Lap Joint Flange

The lap joint flange consists of a stub end welded to the pipe and a backing flange that sits loosely over the stub end. This design allows easy alignment and bolting, making it suitable for low-pressure applications.

Threaded Flange

Threaded flanges are designed with internal threads that can be screwed onto the pipe. They are commonly used for low-pressure applications and are easy to install and dismantle.

Socket Weld Flange

The socket weld flange is a great option for high-pressure and high-temperature applications. Its socket-shaped end is welded to the pipe, creating a secure and leak-proof connection.

Steps To Follow in Welding Flanges

Flange welding is vital in industries where metal structures must be securely joined. To ensure that your welds are strong and secure, the following procedures must be followed:

Step 1: Preparing the Flanges

Start by cleaning the flanges thoroughly, removing any dirt, oil, or debris. Then, using a wire brush or grinder, remove any rust or scale from the surface of the flanges. Once the flanges are clean, place them together and align them correctly.

Step 2: Tack Welding

Tack welding creates small, temporary welds that hold the flanges in place while you complete the final weld. Use a Metal Inert Gas (MIG) or Tungsten Inert Gas (TIG) welder to create small welds around the circumference of the flanges. Be sure to avoid welding in the areas where the final weld will be placed.

Step 3: Final Welding

To create a strong and secure weld, it’s essential to use the correct welding technique and settings. During the final welding process, maintain a consistent speed and distance to ensure a uniform weld.

Step 4: Finishing the Weld

You can finish the weld by grinding it to create a smooth surface. You may also use a wire brush or grinder to remove rough edges or excess material from the weld. Once the weld is smooth, clean the flanges to remove debris or dust.

Benefits of Using Flanges in Piping Systems

The following are the advantages of using flanges in piping systems:


Flanges are versatile components used in various piping systems, including water, gas, oil, and steam. They are available in different materials and sizes, making them adaptable to other applications.

Ease of Installation and Maintenance

Installing flanges is quick and simple, involving aligning and bolting the components together. In addition, because flanges use bolts and nuts to connect, they can be easily detached, which reduces downtime for maintenance work.


Using flanges makes it possible to create complex piping configurations that would be difficult or impossible to achieve with other methods. Also, they allow for greater adaptability and flexibility in the design, making it easier to accommodate changes and modifications over time.

Sealing Reliability

Flanges provide a tight seal between two components, preventing leaks and reducing the risk of damage to the piping system. They also allow gaskets to be installed between them to provide additional sealing, further enhancing the system’s protection.


Flanges are a more cost-effective solution for piping systems compared to other components. They are also reusable, saving money in the long run and reducing maintenance and repair work costs.

Durability and Longevity

Flanges are made of high-quality materials that can withstand harsh operating conditions. They are resistant to corrosion, erosion, and wear, extending the life of the piping system.

Key Considerations in Choosing Flanges

Here are the factors that should be considered when choosing flanges:


Flanges are available in several materials, including carbon steel, stainless steel, and various alloys. The choice of material depends on the type of fluid or gas being transported and the environmental conditions to which the system will be exposed.

For instance, carbon steel flanges are commonly preferred for their affordability and versatility. However, you must consider using stainless steel or other corrosion-resistant alloys if the system operates in a corrosive environment.


When selecting a flange, it is essential to ensure it matches the pipe’s outer diameter. If the flange is too small, it may not be possible to attach it to the pipe. On the other hand, a too-large flange can cause leaks, which can be costly and dangerous.

Pressure Rating

The pressure rating depends on the material and size of the flange. For instance, a carbon steel flange with a 150-pound pressure rating is suitable for low-pressure applications, while a 300-pound is suitable for high-pressure applications.

Flange Face Type

Flanges are available in several face types, including flat face, raised face, and ring joint face. The flange face type determines the type of gasket used to seal the joint between the flange and the equipment.


Several other application-specific factors should be considered when selecting flanges. These include the temperature and pressure of the fluid or gas being transported, the frequency of maintenance, and the location of the piping system.

Industries Using Flanges

Here are some industries that commonly use flanges:

  • Oil and gas
  • Petrochemicals
  • Water treatment
  • Chemical processing
  • Power generation
  • Food and beverage
  • Pharmaceutical
  • HVAC (heating, ventilation, and air conditioning)
  • Construction and infrastructure
  • Marine and offshore
  • Mining and minerals processing
  • Agriculture
  • Aerospace and defense
  • Automotive
  • Medical and healthcare
  • Textile manufacturing
  • Waste management
  • Renewable energy
  • Industrial machinery and equipment manufacturing
  • Packaging and labeling

Trust Coastal Flange for All Your Flange Needs

Whether you need standard or custom flanges, Coastal Flange is your go-to source for all your pipe flange needs. We have 100 years of experience and thousands of flanges shipped each year! We use only the highest quality materials to ensure long-lasting, reliable performance.

Coastal Flange takes great pride in our products’ quality and exceptional customer service. We are committed to providing fast, reliable service at a price you can afford. Moreover, our team of experts is always available to answer any questions and assist you in selecting the right flanges for your project.

Contact us to learn more, or request a quote to get started!

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