5 Important Questions to Ask About Pipe Flange

Most people need to learn what long weld neck flanges are and their use. Some people work in specific industries that encounter the flanges each day. Here you will understand everything you need to know about the basic flanges, including the long weld neck flanges.

Weld-neck flanges


Where do you use flanges the most?

A flange comes disc-shaped, and we use them mostly when building pipelines. According to the Pipeline and Hazardous Materials Safety Administration, 1,382,569 million miles of pipelines deliver oil and gas daily. Long weld necks and other kinds of flanges are a part of pipeline engineering. Flanges are one of the essential parts of pipeline engineering. We use them to connect pipes together and ensure the proper seal.

What is the function of flanges?

Flanges are useful to connect pipes and can also help connect chuck valves, T, and other pipeline parts. Therefore, we consider them a mechanical way to connect pipelines and their parts.

You can weld flanges sometimes, and in other cases, you can hold them together with the fasteners. It all depends on the pipeline engineering and where you can use the flange to determine how well you can connect them.

What are the different flange types?

There are many flanges designed for different purposes. For example, there are high hub flanges, expander flanges, long weld neck flanges, anchor flanges, blind flanges, and more. Within each kind of flange category, there are subcategories.

The metal material may vary, the sizes vary, and how the flange is attached may vary. You can get a lot to learn about the flanges. A proper flange is essential to get off the right seal. A too-large or too-small flange will throw the entire design off.

What is the height of the face in the raised face flange?

The height of the flange face should not be random but, instead, based on the flange ratings. For example, for 300# & 150#, the height of the raised face is 1/16”, which is approximately 1.6 mm, and above 300#, it is 1/4”, which is 6.35 mm.

What is the serration on the flange face, and what type is used on flange faces?

Flange faces could be serrated and smooth type. The flange face with small grooves is known as serration.

The serration is critical as it helps prevent leakages from the flange. Even small damage to the face may lead to the plant shutdown. Thus, if you are working with a flange, ensure to take measures and protect the flange while handling it.

Serration could be concentric or spiral rings. When we talk about concentric ring-type finishing, it is when the fluid used is of very low density. If you use the spiral-type finish with lower-density fluid, it may find a leakage path through the spiral cavity.


The above questions clearly define the pipe flange. The right source, like Texas Flange, will likely offer you a wide variety of high-quality flanges that will fit the project’s needs. Texas Flange will also be able to answer questions and make suggestions to ensure you get the right flange for your project. Call Texas Flange to learn more about our quality flange and how they enhance pipeline projects worldwide.

Variety of Flanges Available at Texas Flange

The type of flange used for a piping application usually depends on the required strength for the flanged joint. Flanges are used to weld connections. In addition, it helps to facilitate maintenance operations.

Let’s dive in to show the key types of flanges with pictures.

Forged Flanges

Welding neck flange

A welding neck flange features a long tapered hub that helps weld the pipe. The flange type is normally used in high/low temperatures and high-pressure applications requiring unrestricted flow if the piping system conveys the fluid.

The absence of pressure drops prevents the adverse effects of erosion/corrosion and turbulence of the metals in the flanged joint proximity.

Long welding neck

Long weld neck flanges are quite similar to weld neck flanges. However, it comes with the exception that the neck is extended and acts like a boring extension.

Long weld neck flanges are usually used on barrels, columns, or vessels.

Slip-on flange

You can connect the slip-on flange to the pipe or the fittings by the two fillet welds, one outside and one executed inside the flange cavity.

The bore size of the slip-on flange is large than the outside diameter for pipe connection, as the pipe has to slide inside the flange that you can connect by the execution of the fillet weld.

Threaded flanges

Threaded flanges are joined to the pipes by screwing the pipe onto the flange without the seam welds. Threaded flanges are available in sizes for up to four inches and multiple pressure ratings; however, they are used mostly in low-temperature applications and small-size piping in low-pressure-like air and water utility services.

Socket weld flange

You can connect socket weld flanges to pipes with the use of a single fillet weld executed on the outer flange side.

As per the ASME B31.1, to execute the flanged connection with a socket weld, the pipe must first insert the flange’s socket until it reaches the bottom of the flange. It then needs to be lifted by 1.6 mm and welded finally.

Lap joint flange

The lap joint flange features a flat face and is always useful in conjunction with the stub end. Lap joint flanges usually resemble the shape of slip-on flanges, except for the radius at the flange face crossing and the bore to accommodate the flanged portion of the stub end.

When we talk about the lap joint flange, it can slip over the pipe and seats on the back of the stub end, and you can keep the two together by the pressure of the bolts.

Blind flanges

Contrary to all the flange types above, blind flanges do not have a center hole. Therefore, you can use the seal or blind in a pipeline or a pressure/valve vessel to block the fluid of the liquid.

Blind flanges need to withstand remarkable mechanical stress due to the system pressure and required bolting forces.

You can easily access the blind flanges to the pipeline, as they can be easily unbolted to let the operator execute the activities while inside the terminal end of the pipe.

Interestingly, while this flange type is easy to manufacture, it is sold at the average premium cost per kg compared to the other flange types.

Special types of flanges

The special types of flanges include:

1. Nipoflange

2. Weldoflange

3. Latroflange or Elboflange

4. Swivel flange

5. Expanding flange

6. Reducing flange


The flanges mentioned above are usually the top flanges available to us. However, you can get in touch with Texas flange if you are looking for top-quality flanges. You can also contact us for any queries regarding the flange function.

Define the Various Grades of Carbon Steel Flanges

Carbon steel flange and end flange connectors are made of carbon steel. Common standards include ASTM A694, ASTM A105N (SA105N), MSS SP-44, DIN 2533. When you accompany, pressure ratings are from class 150 to 2500.

Carbon Steel flange

Carbon steel has a carbon content of up to 2.1% by weight. AISI defines it as:

  • No alloy element (minimum content) is required, as of Va, Ti, Ni, Mo, Cr, etc.
  • The specified minimum of Cu shall not exceed 0.04%.
  • Maximum Mn 1.65%, Si 0.06%.

As the carbon element content increases, the steel becomes more robust and complex after the heat treatment. On the contrary, it becomes less ductile. When without any heat treatment, higher carbon reduces weldability.

Carbon steel may include alloy steel in case it is not helpful as stainless steel.

Different grades of carbon steel flanges

The main component in manufacturing carbon steel flanges is carbon and iron steel. The forged carbon steel flanges help connect pumps, valves, or other equipment—the grade of steel changes on the material and its carbon content.

The different grades of carbon steel flanges are ASTM A350, ASTM A516, ASTM A694, ASTM A182, and ASTM A105. About 1% to 2% is the weight of the carbon in the carbon steel flanges.

The increase in carbon content in the element makes steel stiffer and sturdier. It also makes things less ductile. Higher carbon may reduce weldability if not treated with high heat.

Carbon steel A105 Flanges

Carbon steel A105 flanges are forged steel piping components that are useful for flanges, fittings, and valves in pressure systems at higher temperatures. You can operate on carbon steel flanges between 0 degrees to 550 degrees.

It is suitable for marine engineering and hydrocarbon processes. It has been helpful in gas, oil, and nuclear power plants equipment, valves manufacturing, petrochemical plants, pump manufacturing plants, and other places.

Carbon steel A350 LF2 Low-temperature flanges

Carbon steel A350 LF2 flanges are made with ring-rolled carbon flanges, forged fittings, low alloy steel forged, and valves for low temperatures. These flanges come with extensive pressure resistance, strength, and durability.

The type of carbon steel flange provides machinability when it is forged and hardened. It offers moderate strength. It is mainly in high demand because of its high hardness.

Carbon steel low Alloy A182 Flanges

The carbon steel grade is helpful for stainless steel pipe flanges, valves, and other high-temperature services. The type of steel suits the low corrosion applications. These flanges do not wear out quickly. These flanges are widely used, mainly in the petroleum, paper, and chemical industries.

The features of these flange types suit the most as it stays for a more extended period. It does not require repair after the installation. If you purchase these products from the right place, it will help you ensure their durability.

Carbon Steel A694 flanges

It is the most carbon stress-reliant steel flange material. It suits the high-pressure transmission of oil and gas piping. The products made with this steel are usable in the high-yield service.

The manufacturers of this steel need to build steel that can withstand cryogenic, high temperatures. The high carbon content with heat treatment makes it less ductile. If there’s a lack of heat treatment, it may reduce its ability to weld.

Forged carbon steel flanges

There are different ways you can manufacture flanges. The most prominent way is to forge and cast it. Flanges are plate-like devices that can be added at the end of the pipe; a valve and fitting can put a piping system altogether.


The manufacturers develop flanges that are useful in fittings and pipes. Forged steel has the best mechanical properties than any other product. It has excellent use for industrial purposes. It is often used with an attachment of a valve at the pipe end. It also functions for outlets and inlets.

How to Use Long Weld Neck Flanges in Industrial Applications

Today in the US, hundreds of billions of tons of liquid petroleum products and trillions of tons of cubic feet of natural gas are crisscrossing the nation in the pipe that needs to be connected. For the majority of connections, the long weld neck flange is the one that does the job.

Weld-neck flanges

Weld neck pipe comes in two different neck sizes: long weld neck flange and standard weld neck flange. This blog will discuss the long weld neck flange and its use in industrial applications.

Meaning of a long weld neck flange

Long weld neck flanges (known as LWN) comes with an extended neck that acts as a boring extension. It is also longer compared to the standard weld neck flange.

Welded neck flanges are easy to recognize because they have a long tapered hub that reduces the size from the pipe to the fitting. Industrial long weld neck flanges are also useful in high-pressure industrial applications and high-temperature situations.

Long weld neck flanges are often useful in the petrochemical, gas, and oil industries. They come with nozzles and are useful in replacing the pipes. While a standard weld neck flange’s tip has a weld prep at its neck, long weld neck flanges come in a variety of lengths, with the most common being 9 inches, 12 inches, and 16 inches.

Unfortunately, lengths are based on the parts for every application, so there’s no universal standard length existence for these industrial-long neck flanges.

Long weld neck flanges come with the beveled flange to fit right with the pipe for added strength. Long weld neck flange connections help to improve the pipe flow. Additionally, piping systems are safer when reinforced with long weld neck flanges. It is the type of flange that helps balance the temperature and pressure changes in the liquid that flows in the pipeline.

Long weld neck flanges are often found as anchors in the water mains. The reason is that they can withstand higher pressures; you can connect larger networks of pipes, like those in a factory. You can also use long weld neck flanges in the expansion bends or to reduce or extend pipe sizes.

Why choose long weld neck flanges?

Industrial long weld neck flanges offer additional reinforcement that standard weld neck flanges do not. The long neck guides the pipe into the flange, giving them extra strength.

The extra assurance helps to ensure the safety of the structure, environment, and people when high-pressure fluids and high-temperature are involved. The structure reinforcement provided by an industrial-long weld neck flange is crucial to the stability and safety of industrial and high-pressure commercial systems.

The function of long weld neck flanges

The long weld neck flanges are useful in the following places:

Large pipe networks

Industrial long weld neck flanges are the safest and best choice, whether it is a water main, gas main, or another large piping network. Large networks need high pressure to keep everything in the pipes moving. It results in the strain on smaller pipes and may end up damaging if not accounted for correctly, and this is where industrial long weld neck flanges help.

Office complexes and apartment buildings

Like with any other large pipe network, high pressures are required to keep everything on the move. For that reason, you will commonly find long weld neck flanges that lead into these buildings.

Volatile or hazardous fluids

Wild temperature swings from sub-zero to near-boiling and high pressures may wear on the pipes and fittings used to transport the fluid. Long weld neck flanges may help cut costs by reinforcing the pipes used in high-pressure, high-temperature situations.


Industrial long weld neck flanges are game-changers for high-temperature, high-pressure, or otherwise dangerous amounts of fluid that need transportation. The added strength lent by these pieces helps to ensure the stability, security, and safety of the piping and structures that industrialists depend on daily.

Our team at Texas Flange is experienced, knowledgeable, and ready to assist you with any questions about the best products for your project. Give us a call today!

What is the Function of Flanges and How Do They Work?

The flange industry is wide, and it offers customers a reliable way to connect pipe systems with the various valves, equipment, and other components of virtually any processing system. Flanges are the second most used joining method after welding.

Custom Pipe Flange Fittings

If you use flanges, it adds flexibility when you need to maintain piping systems. It also allows for easy disassembly and improved access to system components.

A typical flanged connection is comprised of three parts:

  • Bolting
  • Gasket
  • Pipe flanges

In many cases, specific bolting and gasket materials are made from the same or approved materials as the piping components you wish to connect. For example, stainless steel flanges are the top choice among some of the most common flanges. However, flanges are available in a wide range of materials, so matching them with your needs is crucial.

Other common flange materials include Chrome Moly, Inconel, Monel, and many others, depending on the application.

The best option for your needs depends on the system in which you intend to use the flange and your specific requirements.

Common flange types and characteristics

Flanges are not a one-type-fits-all kind of solution. If we keep the sizing aside, matching the ideal flange design to your piping system and intended usage will help to ensure optimal pricing, a long service life, and reliable operation.

Here are the most commonly available flange types:

Threaded flanges

It is also known as a screwed flange and has a style with thread inside. The flange bore fits with the matching male thread on the fitting or pipe. The threaded connections mean you can avoid welding in many use cases. If you simply match the threading o the pipes, you wish to connect.

Socket-weld flanges

Ideal for small pipe diameters in low-pressure and low-temperature scenarios, socket-weld flanges feature a connection where you place the pipe into the flange and then secure the connection with a single multi-pass fillet weld. As a result, it makes the style simpler to install compared to other welded flange types while avoiding the limitations associated with the threaded ends.

Slip-on flanges

Slip-on flanges are quite common and are available in large-size ranges. It can accommodate systems with high flow rates and throughput. You intend to connect if you match the flange to the outer pipe diameter. Installation is slightly more as you will need to fillet the weld on both sides to secure the pipe flange.

Lap joint flanges

Lap joint flanges require butt welding of the stub end to the fitting or pipe with a backing flange to create a flanged connection. The design makes this style popular for use in systems with physical systems or space that requires frequent maintenance and dismantling.

Weld neck flanges

Weld neck flanges need butt welding for installation. However, its performance, integrity in the systems with multiple repeat bends, and the ability to use them at high temperatures and high pressure make them a top choice for processing piping.

Blind flanges

Useful for isolation or terminating piping systems, blind flanges are essentially boltable blank discs. When you install them properly and combine them with the correct gaskets, it can achieve an outstanding seal that is easy to remove when needed.

Specialty flanges

The flanges types listed above are quite common. However, various specialized flange types are available to suit various environments and uses. Other options include reducing flanges, orifice, expanding flanges, weld flanges, and nipo flanges.

Flange Facing Types: Making the connection

The design is just a start when you consider the ideal flange for your piping system. Face types are another characteristic that greatly impacts your flanges’ service life and final performance.

Facing types determine the gaskets required to install the characteristics and the flange related to the seal created.

Common face types include:

  • Flat Face (FF)
  • Raised Face (RF)
  • Ring Joint Face (RTJ)
  • Tongue and Groove (T&G)
  • Male & Female (M&F)

Most face types offer one of the two finishes: smooth or serrated. Choosing between the options is crucial as it will determine the optimal gasket for a reliable seal. In general, smooth faces work best with metallic gaskets, while serrated faces help create stronger seals with soft material gaskets.

Flanges Dimensions: The Proper Fit

Apart from the functional flange design, flange dimensions are the most likely factor that impacts the flange choices when updating, maintaining, or designing a piping system. First, however, you must consider how the flange interfaces with the pipe and the gaskets in use to ensure proper sizing.

Common considerations include:

  • Nominal bore size
  • Pipe size
  • Bolt circle diameter
  • Thickness
  • Outside diameter

Flange classification and service ratings

The above characteristics will influence how the flange performs across various environments and processes.

Flanges are often classified based on their ability to withstand pressures and temperatures. It is designated using a number and either ‘class,’ ‘lb,’ or ‘#’ suffix. These suffixes are interchangeable but will differ based on the vendor or region.

Common classifications include:

  • 150#
  • 300#
  • 600#
  • 900#
  • 1500#
  • 2500#

Flange markings and standards

To make the comparison easy, flanges fall under global standards established by the ASME (American Society of Mechanical Engineers) – ASME B16.5 & B16.47.

If you are attempting to verify or replace the existing parts, all flanges must include the markers, typically on their outer perimeter, to aid in the process.


The above guide offers you a solid foundation of the basics of flange design and how to choose the ideal flange for your piping system. However, with a wide range of stainless steel flanges or other available flange materials, it is impossible to list every consideration, detail, or configuration.

You can contact Texas flange if you want the best quality flanges or have any queries regarding the flange function.

Different Types of Flanges for Piping

A flange is a device that is useful for connecting two pipes. It can also help connect the pipe to a choke, valve, tee, or other equipment to form a piping system.

The flanges are pipeline elements that allow the assembly of the parts. It is an element supplied as a separate part or a part attached from the factory to an element such as a pump, valve, or another.

The flange is a type of coupling that can join two lines together with the help of gaskets and bolts in between them. The flange is not something that will individually make the joint. Instead, it can be described as the combination of two flanges or the bolting of two flanges. There would be a gasket in between these flanges.

The gasket between the flanges would give the bolts and seal a force required to seat the gasket and hold the joint together. The flange provides the surface for the gasket to seal and carry the applied force around the gasket. The joint may allow easy reassembly and removal or piping of components.

Flange characteristics

There are a few characteristics of flanges. These include:

# Holes are drilled accurately in the flange for easy assembly.

# The spot facing would ensure the seating of the fasteners

# To obtain maximum strength, the grain flow is controlled

# Unrestricted flow is obtained by accurate and smooth bore

# Good welding is facilitated by machined land and bevel

# To ensure true alignments, all faces are machined within tolerances

Uses of flanges

The need for flanges is increasing every day. Flanges are used for many industrial applications and are one of the best coupling methods to join two pipes. A flange would work properly if the components of the flange function in the right manner.

Flanged joints are useful for the ease of maintenance. Flanges are used when the joints need to dismantle. Specific pipeline maintenance needs it frequently, so the breakout flanges are useful at definite intervals on pipelines.

Need for a gasket in the valve and pipeline

A malleable gasket that could be hard or soft is inserted between the flanges to prevent leaks. Pressure is applied to the gasket by bolting or using a clamp to compress the gasket firmly at a place. The gaskets are made with different materials and can be selected per the process’s temperature and characteristics.

Gaskets are used in a valve to help prevent leakage in the closure mechanism. It also helps to prevent the leakage of fluid into the atmosphere. It is useful in the valves that allow the function of internal mechanisms. It depends on the separate fluid chambers like the pressure balance trim.

Types of flanges

There are different types of flanges for piping. These include:

flanges for piping

Weld neck flanges

The flange type is attached to the pipe by butt welding. These flanges are used for critical services. It is suitable to handle extreme temperatures and pressure because of these features. The flanges are useful mostly for refinery and petrochemical plants. The bores of both the flange and pipe match and it would reduce the erosion and turbulence inside the pipeline.

Slip-on flange

The flange is slipped over the pipe and gets a fillet welded. There will be two kinds of fillet welds, and these welds are at the outside and inside of the flange. The flange connection type is quite fragile compared to the weld neck flange.

Socket weld flange

It is the type of flange bored only at one side. These flanges are helpful for only small-bore lines. The bore of the pipe and bore are the same. Thus it possesses a good flow characteristic. The flange type will be welded to the ID of the pipe and counter board slightly larger than the OD of the pipe. It allows the pipe to be welded and inserted in place.

Threaded flanges

These flanges are made of steel and are useful for special applications. The main advantage of this flange is that you can connect it to the pipe without welding. However, in specific cases, a seal weld is useful in conjunction with the threaded connection.

Blind flanges

These flanges are useful to close the ends that need reopening later. In addition, the flanges are used to blank off the ends of pressure vessel openings, valves, and piping.

The construction of these flanges is done without a bore, from the standpoint of bolt loading and internal pressure. The blind flanges, which come in a larger size, are the most highly stressed flange types.

Lap joint flanges

The type of flange useful in the stub ends when piping costs much. The flanges are cost-effective; the stub must match the flange and pipe in an expensive pipe like stainless steel. The flange can be made of cheap carbon steel material.

Long weld neck flange

The type of flange is similar to the weld neck flanges, and one difference is that their neck is extended and acts as a boring extension. The flange is mostly used on barrels, columns, and vessels.

Orifice flanges

The flanges are useful when an orifice plate or flow nozzle needs an installation. Pairs of pressure tapings are machined into the orifice flanges. Thus it makes separate tappings or carriers in the pipe walls.

Whether you need weld neck flanges, blind flanges, or any other more specialized option, finding something that works well for you must not be tough. At Texas Flange, you get to take a look at different options here.

5 Best Tips to Use Steel Pipe Flanges For The First Time

A pipe flange is a mechanical device that serves the purpose of joining the pipes together. It can be in the form of a welding neck where it is welded to a pipe or other butt-weld fittings.

The threaded flange or flange collar is screwed to the flange with a companion pipe. Other methods include using a lap joint to make connections using a stub end, as well as the common slip-on and socket weld connections.

Steel pipe flanges

Here are five tips for using the steel pipe flange for the first time:

Slip-on flanges for low-pressure services

The preference of slip-on flanges is mainly by the users who prefer flanges that are easy to use, have less installation time, and have low cost.

In addition, they are helpful for non-critical low-pressure services like firewater, cooling water, and other non-challenging pipework owing to their strength being approximately 1/3 lower than that of a weld neck flange, depending on the assembly. The pipe gets welded to the flange hub and bore.

If you want to check on the integrity of the slip-on connection, a magnetic particle, a simple visual test, or a PT test are the approaches you can follow. You can use the slip-on flanges, which come in a variety of sizes greater than NPS ½ (DN 15).

Socket weld flanges in high-pressure pipe works

If you do high-pressure pipework below 2 inches (DN50), a socket weld flange is preferable when space is constrained. It would help if you filleted weld the pipe to the socket weld flange hub. A good welding flange experience is crucial to make the connection since a radiographic examination on the fillet weld is not easy to execute.

If, however, the connection is visual and critical, examination alone will not be enough if it carries out the magnetic failure or penetrates particle tests to check the connection strength.

Lap joint flange in high-cost material pipelines

The working of lap joint connections is good for pipelines that are in high-cost materials such as stainless steel and nickel alloys. It dramatically reduces the total cost of all flanged connections which is required. The stub end, which has been welded to the pipe, and the backing or lapped flanges are used to make a lap joint connection.

You may, for instance, use the stainless steel stub end combined with a carbon steel lap joint flange for a good welded connection at lower costs. This is becoming an increasingly common alternative as the volatility of steel prices becomes an issue.

Connecting weld neck flanges to the butt weld for good performance

There is a tapered hub on the weld-neck flanges. It comes with an end that’s finished as a butt weld and can be connected to butt weld pipe and fittings. You can examine the weld’s quality with ultrasound radiography or visually do it.

The welded connection of weld neck flange or pipe flange features good fatigue as well as mechanical stress performance.

Skilled professionals execute the pipe flange joint process

Trained personnel must be the ones to execute flange joint seals. It helps to prevent dangerous leaks from happening in the pipeline. With the first time use of steel pipes, a properly trained engineer must be the one to execute flange ring joint connections and reference the correct bolt torque data.


Steel pipe flanges are often the best solutions to your multi-stage pipe assemblies, but the material grade is also of concern. Stainless steel is a corrosion-resistant, durable, strong metal, making it an excellent choice for flange fittings in the gas and oil industry when carbon steel will not suffice. If you want more information on steel pipe flanges, contact Texas Flange.

Why Socket Weld Flange is the most recommended?

Socket weld flange has been around a lot in the industry and people are wondering about the reason for their popularity.

Here in this blog, we will dive deep into learning about socket weld flanges. Before anything, let’s first understand its meaning and, how it is distinct from other weld connections.

Meaning of socket weld flange

Socket-weld pipe flanges are typically useful on smaller sizes of high-pressure pipes. These pipe flanges are attached by inserting the pipe into the socket end and applying a fillet weld around the top. It allows for a smooth bore and better flow of the gas or fluid inside the pipe.

Slip-on pipe flange with a hub is a more common connection that comes with published specifications that range from ½” thru 24”.

Socket weld pipe flanges are usually provided with an RTJ facing, flat face, or raised face. When a raised face is necessary for socket weld pipe flanges, the standard height is 1/16” for socket weld pipe flanges under 400#. For socket weld pipe flanges of 400# and up, the standard socket weld pipe flange raised face height is ¼”.

In simple words, a socket weld is a pipe bridging component installed into a recessed area of fitting or flange. The socket can be considered a female member of the joint that harbors the pipe. It is also known as a fillet weld joint as it can be secured by only one fillet.

Applications of socket weld flanges

Socket weld flanges make a good fit for non-critical operations. It is a perfect choice to join small-diameter piping less than 2 NPS. It is not usually usable at daunting pressures and temperatures as it can only resist about half of the forces than that of buttweld.

These possess characteristics where it holds leakage resistance very high along with moderate structural strength. It is why, industries that carry dangerous, toxic liquids employ socket weld fittings.

Apart from this, it has moderate pressure tolerates that may help rank better than tee joint, edge joint, or lap joint. Therefore, it is preferably adopted in pressure conditions lesser than 600 psi. Along with slip ons, these socket connections do not exist per ASME/ANSI B16.5 in 2500# class

Useful in several industrial operations

Good calibration since the fitting is fixed and no additional fastening is required. As it does not require exclusive preparation to secure connections, the costs are cut down to half compared to the butt weld joints.

Apart from that socket weld also offers high strength. Thereby, it is leakage-proof compared to any other type of connection. A socket weld can be either a raised face or a flat-face linkage.

Advantages of Socket weld flanges

Here are some advantages of socket weld flanges:

  • It can replace the threaded flange to minimize the risk of leakage.
  • It doesn’t require beveling before welding.
  • Welding work outside the pipe won’t penetrate the pipe bore.
  • It is recommended for applications where internal welding operations are tough. The sock-welded construction eliminates internal pockets while avoiding the warpage of welding heat and damage to the flange face caused by the weld spatter. It also has the same internal pressure as the sliding on the flange with better fatigue life.

Downsides of socket weld flanges

The only bargain here is that the socket weld flange has a gap requirement of 1.6mm towards the pipe portion that receives the joint, i.e., at the bottom of the pipe.

It is done to compensate for the expansion that happens during the thermal setting at the joint. However, the setting of excess metal at the joint makes the socket weld vulnerable and creates a hotspot for stress at the particular portion.


If you compare socket weld flange to any other weld, you can easily make out why it is relied upon and why its popularity is wide. Texas Flange is one of the leading exporters of a wide range of flanges. If you want to know more about socket weld or any other flange, you can contact us today, and our experts will help you select the best flange as per your preference.


Flanges Used In The Oil and Gas Industry

Connections through pipes are a crucial channel for transporting steam and fluids along with gas from refineries to factories or across continents as well. Flanges are one of the efficient components in a method to connect pipes. Along with forging connections in a piping system,

flanges regularly permit the worker with inspection points which are easy to modify and clean these systems. Different alloy grades are useful to produce various flanges that are a part of piping systems in the gas and oil industry.

Therefore, these flanges are required to not only be durable, but they must also be easy to install and maintain.


Below are a few of the commonly sighted flange types used in the gas and oil industry:

Weld Neck Flange

Useful in high-pressure environments, it is easy to recognize the weld neck flanges because of the beveled hub. Moreover, weld neck flanges are particularly well suited to be used in repeat bending conditions. These flanges are attached to a piping system by means of welding the pipe to the flange neck.

Therefore, stainless steel grades have good weldable properties preferred for its manufacture. Weld neck types not only reduce the stress concentration from the base of the hub but also aid the transference of stress from the flange to the pipe.

Slip-on Flange

Slip-on flanges are designed to be used in lower-pressure, low-temperature processes. These are favored by the engineers in the gas and oil industry due to their economical value in comparison to the weld neck flanges.

This kind of flange is slipped over the pipe, following which they are welded both on the outside and inside to increase its strength and prevent leakage.

Lap joint

A lap joint flange is a two-part attachment preferred to be used in processes where space constraints and frequent dismantling are primary requirements. In this type of attachment, the lap joint stub end is welded to the pipe, and the loose backing flange is used in conjunction to slip over the pipe or stub end.

As the backing flange is not in contact with the product in the piping systems, moderate corrosion resistance and less expensive material with high hardness like carbon steel is good to use. Also, the stub ends need to be highly corrosion-resistant material with good mechanical properties.

Threaded Flange

It is useful in circumstances where there’s a need for quick fixes. Threaded flanges or as referred to as screwed flanges are produced with threaded bores that aid in a fast and simple attachment.

A threaded flange is usually attached to the pipe without a need to carry out a welding operation due to the pre-existing threads. Typically, threaded flanges are seen in the processes where the pipes in the systems are used to transport water or air. Threaded flanges are best used in low-pressure environments and temperatures.

Blind Flange

The production of blind flange is done without a bore at the center and the main purpose of using it is to blank off the end of valves or piping systems or even pressure vessel openings.

Blind flanges could also be used in conjunction with any other flange to isolate a piping system in the gas and oil industry. Furthermore, they make an excellent manhole, especially if they perform the tasks of terminating the flow in the vessel or a piping system.

Socket Weld Flange

It is recommended to be used for low-temperature and low-pressure settings, the socket weld has a static strength that is equal to a slip-on flange. A socket-weld connection is made with the pipe by using a filler weld performed on the outside of the flange.

Socket weld flanges are designed to be used in processes where small bore piping is needed. However, due to some corrosion issues, it is best to avoid these in a few processes.

If you still have any doubts about how to select flanges for the oil and gas industry and what to look for, do let us know in the comment section or call us today!

What are Various Types of Flanges Used in Piping Applications?

The main use of flange is to connect pumps, pipes, valves, and other equipment to make a pipework system. Usually, flanges are threaded or welded, and you can connect two flanges by bolting them with gaskets and providing a seal that gives easy access to the piping system.

These flanges are available in many types like socket weld flanges, blind flanges, weld neck flanges, slip-on flanges, etc.

Here are various types of flanges used in piping systems that depend on other factors.

Types of flanges

Here are a few most important types of flanges available for piping applications:

Slip-on flanges

Slip on Flanges

The slip-on flange is a ring (with or without a hub) placed over the pipe’s end. The flange face extends from the end of the pipe by a sufficient distance to apply a welded bead to the inner diameter. As the name suggests, these flanges slip over a pipe and are known as slip-on flanges.

Weld neck flanges

Weld neck flange is also known as a high-neck flange or tapered hub flange. The weld neck flange has a neck that can properly transfer the pipe tension. It also helps to reduce the pressure gathered at the bottom of the flange. It is compatible with pipelines that operate at low or high temperatures and withstand high pressure.

Socket weld flanges

The socket weld flanges are connected on the outside just by a fillet weld. It is often not advisable for critical services. These are useful for the small-bore lines in your system. The static strength is equivalent to slip-on flanges, but the fatigue strength is 50 percent higher than double-welded slip-on flanges. Often used as an alternative to weld necks when space is a constraint.

Blind flanges

The production of blind flanges happens without a bore and is utilized to blank off the ends of pressure vessel openings, valves, and pipes. If you look from the point of view of bolt loading and internal pressure, the most overstressed flange types are blind flanges which are quite bigger.

Lap joint flanges

Lap joint flanges are useful with stub ends when the pipe is made of expensive material. E.g., a carbon steel flange can be added to the stainless steel pipe system as the flanges do not come into contact with the substance in the pipe.

Threaded flanges

A Note On Orifice Unions - ASMEANSI B16.36

Threaded flanges look identical to slip-on flanges, but the key difference is that the threaded flange is bored out to match the inside diameter of the particular pipe. The threaded flange is a type of flange that has taper pipe threads in its bore conforming to ASME B1.20.1 and is helpful in piping systems.

Materials useful to manufacture flanges

Pipe flanges can be manufactured from many different materials that depend on the piping material and requirements of the application. Selection depends on the factors such as economy, flow pressure, operating temperature, and environmental corrosion. Some of the most common materials include the following:

Carbon steel

It is steel alloyed usually with carbon. The high strength and hardness increase with carbon content, lower melting point, and ductility. This is the most common material grade.

Alloy steel

It is steel alloyed with one or more elements that change or enhance the properties of steel. Common alloys include chromium, molybdenum, nickel, vanadium, and manganese.

Stainless steel

It is steel alloyed with chromium in amounts above 10%. Chromium enables stainless steel to have a much higher corrosion resistance than carbon steel which rusts readily from air and moisture exposure.

Cast irons

Iron when it is alloyed with silicon, carbon, and several other alloys makes cast iron. Silicon forces carbon out of the iron and forms a black graphite layer on the exterior of the metal. Cast irons have good machinability, castability, and fluidity.


It is a low-density, ductile, and malleable metal with medium strength. It has better corrosion resistance compared to any other typical alloy and carbon steel. It is most useful during flange construction that requires low weight and strength.


It is an alloy of zinc and copper and often comes with additional elements such as tin or lead. It is characterized by good conductivity, cold ductility, high-temperature ductility, and good strength.


(Note we do not offer polymer grade materials but have written on them for your benefit below)

Polyvinyl chloride or PVC is a thermoplastic polymer that is easy to assemble, durable, and inexpensive. It is resistant to both biological and chemical corrosion. The addition of plasticizers makes it more flexible and soft.

Performance Features

Performance features are the flange properties that may be dependent on many other factors but are essential to consider. The properties include the following:


It is the toughness or strength of a pipe flange under pressure or stress. Durability is dependent on the flange compatibility and the flange design with the pipes and the material strength.

Easy of assembly

It is a qualitative measure of the efficiency of the disassembly and assembly process. For applications with flange used as a fix or temporary attachment, the ease of setting up and taking down is crucial.


It is the heaviness or mass of the flange. It is dependent on the material density and size. Industrial buyers must consider the strength of the pipe or pipe support while dealing with high or large-density flanges.


You can make out from the above different types of flanges, manufacturing, and performance features. You can choose the right steel flange manufactured from different materials like stainless steel, low alloy steel, carbon steel, duplex steel, or many more.

Choosing the right flange with the right material and knowing the elements that it faces during the application that uses the piping method is critical. We hope that this blog will help you identify the key things before purchasing flanges. To learn more about flange basics, visit https://www.texasflange.com/flange-basics/