Jan. 13, 2025
Steel flanges are a commonly used tool when it comes to piping of any sort. There is a range of different styles and types of flanges. Taking the time to learn about specific types might assist you in finding the flange that is going to work for you and for the job you have in mind.
Weld neck flanges are a type of flange that has a neck that has the ability to move the location of the pipe tension. The flange can help to reduce the overall pressure that gathers at the bottom of the flange to help reduce it. This type of flange has a hub and a tapered neck that is going to be easy to spot and identify.
The neck of the flange is meant to help offer shielding for high-pressure situations as well as for large temperature shifts from high to low. The neck passes through the wall thickness directly from the pipe.
These flanges are most often used in high-pressure pipes or those that need the pressure to be distributed at the connection so that it does not bust or compromise the seam. This type of flange is one that is most often used for high pressure pipes, and you can get flanges with longer or shorter nozzles. This all depends on what you need it for and what the overall pressure is going to be.
Looking at an example, if you have a pipeline that is under 2,000 PSI, this pressure is rather high, so you would need to ensure that where you are joining sections of pipe together, the pressure does not build up and does not focus on that weak point. A weld neck flange or nozzle flange is going to help distribute that pressure and take it away from the joint so that it is less likely to burst and less likely to experience damage.
When choosing your pipe flange, it is always best to look at the different types of flanges that are out there and determine which flange is going to work best for your needs. These flanges are going to be widely varied and with careful inspection, you can find that flange fitting your job and your particular needs.
Flanges have many types like - Welding Neck, Slip On, Socket Weld, Lap Joint, Threaded, and Blind flange. Here are few description about flanges.
Welding Neck Flange - Welding Neck Flanges are easy to recognize at the long tapered hub, that goes gradually over to the wall thickness of a pipe or fitting.These flanges are bored to match the inside diameter of the mating pipe or fitting so there will be no restriction of product flow.
Slip on Flange - The calculated strength from a Slip On flange under internal pressure is of the order of two-thirds that of Welding Neck flanges, and their life under fatigue is about one-third that of the latter.
Socket Weld Flange - Socket Weld flanges were initially developed for use on small-size high-pressure piping. Their static strength is equal to Slip On flanges, but their fatigue strength 50% greater than double-welded Slip On flanges.
Slip on flange has equal static strength as Socket weld strength. Still, Socket connection is more powerful than slip on flange. Above information, I have taken after reviewing may companies like CHW Forge, Bharat, Maharashtra Forgings and many more.
4
moltenmetal
(Chemical)
31 May 16 12:17
Quote (ramprakash11)
Slip on Flange - The calculated strength from a Slip On flange under internal pressure is of the order of two-thirds that of Welding Neck flanges
Rubbish.
Slip-on flanges have the same B16.5 pressure ratings as the other types- so unless you're designing outside a piping code, any "calculated strength under internal pressure" is pretty much meaningless.
The stress intensification factors used in flexibility and fatigue analysis are of course different. Anything attached with fillet welds rather than full penetration welds is going to suffer from this problem. The benefit of fillet welds though is substantially higher welding productivity. Radiography of a socket-welded joint doesn't tell you anything useful so doing it is a waste of time- you can see that as a benefit or a disadvantage depending on your perspective.
Socket welding flanges, like most socket welding components, are used to 2" NPS and no higher. Socket welding flanges rely on one fillet weld so their SIFs are quite unfavourable. They also have a huge crevice for the initiation of corrosion and to store material to ensure that you can never really clean the piping. But they find lots of successful use in small lines.
Slip-ons have a smaller raised face (with an ID greater than the OD of the pipe), which means that if you use spiral wound gaskets, you need to use special dimensions. They require two welds, but don't have the crevice. They also allow easy adjustment for alignment during fitting.
Rubbish.Slip-on flanges have the same B16.5 pressure ratings as the other types- so unless you're designing outside a piping code, any "calculated strength under internal pressure" is pretty much meaningless.The stress intensification factors used in flexibility and fatigue analysis are of course different. Anything attached with fillet welds rather than full penetration welds is going to suffer from this problem. The benefit of fillet welds though is substantially higher welding productivity. Radiography of a socket-welded joint doesn't tell you anything useful so doing it is a waste of time- you can see that as a benefit or a disadvantage depending on your perspective.Socket welding flanges, like most socket welding components, are used to 2" NPS and no higher. Socket welding flanges rely on one fillet weld so their SIFs are quite unfavourable. They also have a huge crevice for the initiation of corrosion and to store material to ensure that you can never really clean the piping. But they find lots of successful use in small lines.Slip-ons have a smaller raised face (with an ID greater than the OD of the pipe), which means that if you use spiral wound gaskets, you need to use special dimensions. They require two welds, but don't have the crevice. They also allow easy adjustment for alignment during fitting.
LittleInch
(Petroleum)
31 May 16 13:39
You really need to back up your statement and look closely at whatever reference you got that from. There is a lot of difference between guidelines and "rules of Thumb" and what is officially permitted by the code.
I agree with everything molten metal says.
ramprakash.You really need to back up your statement and look closely at whatever reference you got that from. There is a lot of difference between guidelines and "rules of Thumb" and what is officially permitted by the code.I agree with everything molten metal says.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
bimr
(Civil/Environmental)
31 May 16 22:48
Slip-on Flanges. Slip-on flanges are preferred to weld-neck flanges by many users because of their initial low cost and ease of installation. Their calculated strength under internal pressure is about two-thirds of that of weld-neck flanges. They are typically used on low-pressure, low-hazard services such as fire water, cooling water, and other services. The pipe is &#;&#;double-welded&#;&#; to both the hub and the bore of the flange, but, again, radiography is not practical. MP, PT, or visual examination is used to check the integrity of the weld. When specified, the slip-on flanges are used on pipe sizes greater than NPS 2¹&#;&#; (DN 65).
Flange Types. Several different flange types are permitted by the standards listed in Table C7.5, as principally covered by ASME B16.5. These include different types of attachment to the pipe including threaded, lapped, and welded as covered in more detail by Chap. A2 of this handbook. Of the welded type, most flanges are the butt-welded, slip-on, or socket-welded types. The majority of flanges are butt- welded, which are more commonly referred to as the welding neck flange. Socket- welded flanges are typically limited to small-diameter connections less than NPS 2 (DN 50). Slip-on flanges fit over the outside diameter of the pipe and are attached with fillet welds at both the pipe end and off the hub end of the flange.
Typical restrictions on the use of slip-on flanges include:
&#; While available in most pressure classes, slip-on flanges are more typically limited to Class 300 or lower pressure rating in process plant piping. The available raised face gasket seating area can preclude commonly used gaskets in the case of slip- on flanges for higher class piping.
&#; They are limited to services with design temperatures below 750°F (400°C).
&#; They should not be used where the specified corrosion allowance exceeds 0.125 in (3 mm).
Many pipe designers are reluctant to use slip-ons for higher pressures, since (1) the joint between the flange and pipe is not as strong as in the welding neck type; and (2) the junction of the flange and pipe is more susceptible to corrosion.
http://www.wmhuittco.com/images/Article_2_Piping_D...
From Piping Handbook by Mohinder L. Nayyar:Slip-on Flanges. Slip-on flanges are preferred to weld-neck flanges by many users because of their initial low cost and ease of installation. Their calculated strength under internal pressure is about two-thirds of that of weld-neck flanges. They are typically used on low-pressure, low-hazard services such as fire water, cooling water, and other services. The pipe is &#;&#;double-welded&#;&#; to both the hub and the bore of the flange, but, again, radiography is not practical. MP, PT, or visual examination is used to check the integrity of the weld. When specified, the slip-on flanges are used on pipe sizes greater than NPS 2¹&#;&#; (DN 65).Flange Types. Several different flange types are permitted by the standards listed in Table C7.5, as principally covered by ASME B16.5. These include different types of attachment to the pipe including threaded, lapped, and welded as covered in more detail by Chap. A2 of this handbook. Of the welded type, most flanges are the butt-welded, slip-on, or socket-welded types. The majority of flanges are butt- welded, which are more commonly referred to as the welding neck flange. Socket- welded flanges are typically limited to small-diameter connections less than NPS 2 (DN 50). Slip-on flanges fit over the outside diameter of the pipe and are attached with fillet welds at both the pipe end and off the hub end of the flange.Typical restrictions on the use of slip-on flanges include:&#; While available in most pressure classes, slip-on flanges are more typically limited to Class 300 or lower pressure rating in process plant piping. The available raised face gasket seating area can preclude commonly used gaskets in the case of slip- on flanges for higher class piping.&#; They are limited to services with design temperatures below 750°F (400°C).&#; They should not be used where the specified corrosion allowance exceeds 0.125 in (3 mm).Many pipe designers are reluctant to use slip-ons for higher pressures, since (1) the joint between the flange and pipe is not as strong as in the welding neck type; and (2) the junction of the flange and pipe is more susceptible to corrosion.
LittleInch
(Petroleum)
1 Jun 16 08:17
I don't much like slip on flanges, but you need something better than that before you consign them to only have 2/3 the "calculated strength under internal pressure".
yup - a guideline. A quote from a piping manual is not a calculation referenced back to anything.I don't much like slip on flanges, but you need something better than that before you consign them to only have 2/3 the "calculated strength under internal pressure".
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
KevinNZ
(Mechanical)
2 Jun 16 01:36
"Their calculated strength under internal pressure is about two-thirds of that of weld-neck flanges"
Where does this come from?
Use the pressure rating in the flange code which are the same for all flange types.
You can design custom flanges to the pressure vessel codes but you will be making your life hard if you start checking standard flange dimensions to code calculations.
As posted above, The only difference the pipe code looks at is SIFs for the flange type for pipe stress. There are also some size application limits, Pressure rating is not effected.
racookpe
(Nuclear)
2 Jun 16 14:13
Many times faster Field fit, more accurate field alignment (or correction of mis-alignment) from old pipes or old equiment, and the need for accomodating installation uncertainities are very big advantages. Sometimes.
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When it comes to flanges, choosing the right one for the job is important. Flanges in piping systems connect pipe sections and valves and offer easy access for maintenance. One of the most reliable and versatile flanges is the weld neck flange. When considering a weld neck flange for your project, the aluminum weld neck flange is an often overlooked option. In this blog post, we will dive deeper into the advantages of aluminum weld neck flanges and why they may be the right choice for your application.
Aluminum Weld Neck Flanges are pipe flanges typically used in piping systems to facilitate the connection between two piping sections. These flanges are welded together with a neck portion, allowing for increased strength and durability due to the full penetration weld joint. They come in different sizes and shapes depending on the applications they&#;re suited for.
One of the most significant benefits of aluminium weld neck flanges is their corrosion resistance. Aluminum is a highly corrosion-resistant material, and its use in flange manufacturing helps to reduce the risk of valve or pipeline failure. Aluminum weld neck flanges are suitable for use in corrosive environments, such as seawater, chemicals, or acidic gases that may cause other flanges to corrode over time.
Aluminum is also very lightweight and strong, making it perfect for use in applications where weight is a concern. Aluminium weld neck flanges are also more durable than other flanges, making them ideal for harsh and high-pressure applications. Their durability, coupled with their lightweight design, can prolong the life of a pipeline or valve.
Aluminum weld neck flanges are known for their ease of installation, and they are a perfect option when you need quick and easy access for maintenance or modification. In addition, they do not require any special tools or techniques for installation, making them easy to integrate into your system.
Aluminum weld neck flanges are a cost-effective solution for many applications because of their low material cost, long life span, and reduced maintenance requirements. This makes them a more affordable option than other more corrosion-resistant materials like stainless steel or titanium.
The sleek and streamlined design of aluminium weld neck flanges also makes them an aesthetically pleasing option. They are less noticeable than other flanges and can give your system a more polished and professional appearance.
When selecting the right flange for your piping system, aluminum weld neck flanges are an excellent choice for various industries and applications. Their corrosion resistance, lightweight design, easy installation and maintenance, cost-effectiveness, and streamlined design make them the perfect solution for many projects. If you are considering using aluminium weld neck flanges for your next project, reach out to a trusted manufacturer who can help you make the best decision for your industry and application.
Weld neck flanges, often referred to as welding neck flanges, are essential in piping systems that demand high durability, strength, and performance under extreme conditions. Their unique design and robust features make them indispensable in certain industries.
This guide explores the intricate design, performance benefits, material options, and applications of weld neck flanges. Keep on reading to know more about weld neck flanges.
Weld neck flanges are meticulously designed to provide superior performance, even in the most demanding applications. Their structural features offer optimal functionality and reliability.
The hallmark of a weld neck flange is its long-tapered hub. The latter ensures superior strength by evenly distributing stress along the length of the flange. This feature reduces the likelihood of mechanical failure, particularly in high-pressure or high-temperature systems.
A butt weld connection joins the flange to the pipe, creating a seamless and leak-proof joint. This method provides superior strength compared to other flange types, such as slip-on or socket weld flanges.
The bore diameter of a welding neck flange matches the pipe size, ensuring a smooth transition of flow and eliminating potential turbulence or pressure drops.
Weld neck flanges are available in standard sizes from 1/2&#; to 24&#;, with special custom sizes manufactured up to 60&#; to meet unique application requirements.
Weld neck flanges excel in high-pressure and high-temperature applications due to their advanced engineering and structural integrity.
A defining feature of weld neck flanges is the gradual tapering of their hub, a design that ensures optimal stress distribution. When subjected to internal pressures or fluctuating temperatures, piping systems often experience stress concentration at connection points. The tapered hub of the weld neck flange minimizes this risk by evenly dispersing stress along the length of the flange and into the pipe.
Weld neck flanges are engineered to handle substantial bending forces caused by external factors like:
One of the standout features of weld neck flanges is their ability to maintain a consistent bore diameter between the pipe and the flange. This precise alignment minimizes turbulence within the pipeline, ensuring:
The smooth interior surfaces of weld neck flanges, coupled with their precise alignment, result in minimal energy loss as fluids or gases traverse the system. A stable pressure profile within the system reduces the strain on pumps and compressors, ensuring consistent performance over time.
Weld neck flanges are crafted from a variety of materials to meet the diverse requirements of industrial applications. These include environments with corrosive chemicals, high temperatures, or extreme pressures.
Common Material Options Include:
Carbon steel is a widely favored material for weld neck flanges due to its strength, durability, and cost-effectiveness. This material is ideal for high-pressure systems operating in non-corrosive environments. Its key characteristics include:
Stainless steel weld neck flanges are renowned for their superior corrosion resistance and durability, making them suitable for challenging environments. Key benefits include:
Explore Stainless Steel Flange
Nickel alloys are the material of choice for the most extreme conditions, offering unmatched resistance to high temperatures and corrosive environments. Features include:
Duplex steel combines the best of both carbon steel and stainless steel, offering balanced strength and corrosion resistance. Its properties include:
Weld neck flanges stand out for their ability to handle high-stress and high-fatigue scenarios. Their superior strength and resilience make them an ideal choice for critical systems.
Designed to withstand cyclic loading and fluctuations, weld neck flanges are perfect for applications requiring frequent start-ups and shutdowns.
The butt weld connection and tapered hub design enhance their capacity to endure extreme internal pressures.
Systems with varying operating conditions, such as fluctuating temperatures and pressures, benefit from the structural integrity of weld neck flanges.
Unlike slip-on flanges, the design of weld neck flanges ensures that stress is distributed evenly, reducing the risk of material fatigue or failure.
The versatility and durability of weld neck flanges make them suitable for a wide range of industrial applications. They are particularly advantageous in environments that require strength and resilience.
Ideal Use Cases:
Weld neck flanges are used in pipelines and systems operating under high pressures, where leak prevention and durability are critical.
These flanges perform exceptionally well in cryogenic conditions, maintaining their structural integrity at sub-zero temperatures.
Their robust construction and material versatility make them reliable in high-temperature systems such as boilers, reactors, and steam pipelines.
Applications involving corrosive media, abrasive materials, or heavy mechanical loads benefit from the superior performance of weld neck flanges.
To ensure consistency and quality, weld neck flanges adhere to globally recognized standards. These standards define dimensions, pressure ratings, and material specifications. Common standards include:
Learn More Flange Dimensions>>>
Long&#;an Flange is a leading manufacturer of welding neck flanges, renowned for its innovation, quality, and customer-centric approach. Specializing in stainless steel flange production, Long&#;an ensures exceptional performance in corrosive and high-temperature environments.
Weld neck flanges are an indispensable component for systems requiring strength, reliability, and efficiency under extreme conditions. Their unique features, such as the long-tapered hub design, butt weld connection, and adherence to stringent standards, make them a preferred choice in high-pressure, high-temperature, and corrosive environments.
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