Aside from welding, flange welds are the second most often utilized means of connecting pipe systems to different equipment, valves, and other components of nearly any processing system.
Allowing for quicker disassembly and better access to system components is facilitated by the use of flanges in pipe systems.
If you’re new to flange weld design, this guide will provide you with a good grounding in its fundamentals.
Neck Flange Welding
A welding neck flange features a unique long tapered hub to enhance the union’s strength. However, while working under high pressure or at temperatures below zero, the joint will be put under a great deal of stress.
Flanges with taper are used to make the transition between pipe and fitting wall thicknesses easier. If the lines grow or other fluctuating pressures cause recurrent bending, this tool is important to have on hand.
In addition to reducing joint erosion and joint stress, the inner bore of these flanges, which is matched to the ID of the mating pipe or fitting, also has this effect. Turbulence is avoided at the junction because the flow is unrestrained. As a consequence of this method, erosion is reduced.
Radiographs are excellent for detecting defects in neck flange welding.
One full penetration V weld (Butt-weld) is all that is needed to join this flange type to a pipe or fitting (Tapered hub or high hub flanges).
There is also the long weld neck flange, which looks like the ordinary weld neck flange but is longer. It may be used in a variety of ways, including a barrel or column.
Slip-On flange
In terms of durability, slip-on flanges are inferior to neck flanges. This means that its predicted strength under internal pressure and life expectancy is significantly reduced.
Low-pressure applications where leaking isn’t a big issue might benefit from affordable and easy-to-install slip-on flanges.
Slip-on flanges have the added advantage of not necessitating a substantial amount of line longitudinal space to be placed.
Additionally, they are simpler to align thanks to the availability of a large variety of pipe diameters, and they do not require precision pipe cutting.
The connection to the pipe must be double-welded if there is no neck on which to rest it. Two filet welds are used on both the outside and inside of the flange.
The slide-on flange has the disadvantage of requiring both the pipe and the fitting to be welded before it can be put into use.
In order to employ flange and elbow or elbow/tee combinations, the straight end of the flange is required.
Use in high-pressure or hazardous material applications is not advised.
Socket Weld Flange
Socket Weld flanges were originally developed for high-pressure, small-diameter pipe systems.
It has the same static strength and fatigue strength as slip-on flanges, but it is 50 percent stronger than double-welded slip-on flanges in this regard.
Before arc or MIG welding, the flange or fitting must be separated from the pipe by at least 1/16′′ to 1/8′′.
By reducing the residual stress and enabling the pipe to expand on the inner side of the weld, this method keeps the fitting’s weld from cracking.
Flanges and pipes are connected by a single fillet weld that is visible from the outside.
Per ASME B31.1 1998 127.3, the pipe or tube must be inserted to its greatest length into the socket before welding. It’s time to get ready for welding! (E). After that, it’s taken out of the socket by about 1/16″ (1.6 mm) from the pipe’s end and disposed of.
Because the weld is on the exterior of the pipe, socket weld flanges are less likely to damage the pipe’s inside.
Threaded flange leakage is significantly minimized because of the lack of bevel prep required for socket weld flanges before welding.
This flange’s drawbacks include its need for a gap to be constructed.
- Welders with specialized training and welding machines with advanced control, such as Dekopro dual-voltawge welder, are needed to guarantee that the 1/16′′ gap is achieved.
- The second reason is that the expansion gap encourages cracking, particularly in anti-corrosive pipes like those made of stainless steel.
- Cracks between the pipe and the flange will lead to corrosion, which will need more maintenance.
- This flange is also prohibited in several procedures.
Lap Joint Flange
Lap joints have many similarities to other flanges; however, they do not have raised faces.
- They are joined together by a “Lap Joint Stub End.”
- These flanges resemble Slip-On flanges except in that the bore has a curved radius.
- Because of their flanged ends, stub ends are meant to be slid over the pipe.
- In order to allow the lap joint flange to move freely, the pipe’s stub end is then welded to the pipe.
Thus, they are suitable for low-stress circumstances.
Lap joint flanges provide a variety of advantages.
- The pipe may rotate freely around the flanges while dismantling for inspection and cleaning, making it simpler to align the opposing flange bolt holes.
- Because they are not in contact with the fluid, carbon steel flanges and corrosion-resistant pipes may be utilized, which might save a lot of money in the long run.
- Flanges may be saved from systems that are quickly degrading or corroding and repurposed.
Stub End
As a backing flange for lap joints, Stub Ends are often employed. However, they may also be used for slip-on applications.
There are stub ends available for purchase in most pipe diameters. The three choices are A, B, and C.
- The support flange for the lap joint may be machined to fit Type A
- In the case of Type B, a normal slide-on flange is needed
- Whereas Type C may make use of lap or slip joints
Size and tolerance requirements are specified in the ASME B16.6-9 standard. All Stub Ends must meet MSS SP43 specifications.
Threaded Flange
As a result, no welding is required in order to attach the pipe to its threaded flange.
This is accomplished by the use of corresponding threads.
- Using a seal weld in conjunction with the flange’s threaded connection isn’t always essential.
- Threaded fittings are still available in a broad variety of diameters and pressure ratings for use in smaller pipe sizes up to 4.00′′.
- In situations where the thickness of the wall is critical, a threaded flange or fitting is suitable because of the thread.
- Small wall thicknesses make threading difficult.
Threaded steel pipe used in steam or water systems with pressures more than 100 psi and temperatures greater than 220°F must be seamless and meet the requirements of ASME B36.10 schedule 80.
The two pipe ends may be sealed with a lens pad and sealing surface in addition to the two types of threaded flanges.
A threaded flange is mostly used in the production of ammonia.
Conclusion
Flange weld dimensions are more important than a flange’s functional design when it comes to influencing a pipe system’s construction, maintenance, or upgrade.
However, you must take into account how the flange is attached to the pipe and the gaskets used to guarantee adequate size.
One style of flange weld does not meet all situations. Choosing the right flange design for your pipe system and intended use can assure dependable operation, a long service life, and the most cost-effective option.
Mercer Industries 730030 Pipe Marking & Cutting Guide 2 3/8"
Product DescriptionFour pipe marking tools in 1, now one tool for all your marking tasks. Saddle cut, 45 degrees, 22-1/2 Degree and 90 Degree.
Spring loaded hinge keeps guide secure on pipe
Accurate angle slots create precise markings for professional results
Crafted from 16 GA. Epoxy coated steel for durability and strength
Reusable over and over again
Product Details| Brand: | Mercer Industries |
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| Model #: | 730030 |
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| Warranty: | 90 day warranty against manufacturer defects |
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| Size: | 2 3/8" |
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| Dimensions: | 4.5 X 2.375 X 2.375 inches (Length X Width X Height) |
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| Price: | $15.54 |
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Mercer Industries 730030 Pipe Marking & Cutting Guide 2 3/8"
Mercer Industries 730030 Pipe Marking & Cutting Guide 2 3/8"
$7.65
@ Amazon.com (Save 15%)
Product DescriptionProduct Details| Brand: | |
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| Dimensions: | 7 X 4.25 X 0.5 inches (Length X Width X Height) |
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| Price: | $7.65 (Save 15%) |
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Sawyer Mfg Company - Pipefitter's Handbook (Yellow Book) - Comprehensive Guide for Pipe Dimensions, Welding Specs & Fittings - Durable Reference for Field & Workshop
Mercer Industries 730030 Pipe Marking & Cutting Guide 2 3/8"
Product DescriptionIncludes (1) 1-5/8" Guide, (1) 1-7/8" Guide, (1) 2-3/8, (1) 2-7/8, (1) 3-1/2, (1) 4-1/2
Cuts at 45°, 90°, 22.5°, and saddle cut
Lightweight yet durable metal construction
Magnetic., flexible "forever hinge"
Product Details| Brand: | NationWide Products-Pipe Pro |
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| Model #: | 1-5/8, 1-7/8, 2-3/8, 2-7/8, 3-1/2, 4-1/2 |
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| Color: | Multicolor |
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| Price: | $109.99 |
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NationWide Products-Pipe Pro 6Piece Magnetic Metal Pipe Cutting Guide Kit, Steel
Mercer Industries 730030 Pipe Marking & Cutting Guide 2 3/8"
Product DescriptionFits 1-3/4" Tube – Ensure you choose the correct size for your project.
Fits 44.45mm O.D. – Metric compatibility for precision fit.
Spring Temper Stainless Steel Pins – Provides durability and accuracy for repeated use.
6061 Aluminum Inner Core – Lightweight yet strong for professional-grade performance.
Rugged ABS Housing – Built to withstand tough shop and field conditions.
Precision Pipe & Tube Fitting Tool – Achieve perfect contour fits for welding & fabrication.
Product Details| Brand: | Pipemaster |
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| Model #: | P-T175 |
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| Size: | Tube - 1-3/4" |
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| Color: | Silver |
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| Dimensions: | 7 X 4 X 4 inches (Length X Width X Height) |
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| Price: | $59.40 |
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P-T175 (1-3/4" Tube) – PipeMaster Contour Gauge Pipe & Tube Fitting Tool – Welding & Fabrication Notcher for Precise Coping & Joint Layout – Easy-to-Use Pipe Template
Mercer Industries 730030 Pipe Marking & Cutting Guide 2 3/8"
Product DescriptionIncludes (1) 1-5/8" Guide
Cuts at 45°, 90°, 22.5°, and saddle cut
Lightweight yet durable metal construction
Magnetic, Flexible "forever hinge"
Product Details| Brand: | Best Goods For You |
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| Model #: | 158M |
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| Color: | Green |
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| Price: | $20.99 |
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Pipe-PRO 158M Magnetic Metal Pipe Cutting Guide, 1-5/8 in, Steel
Mercer Industries 730030 Pipe Marking & Cutting Guide 2 3/8"
Product DescriptionWidely Applicable: The pipe cutting guide includes three sizes: 1-7/8"、2-3/8" and 2-7/8 ". The cutting of 22.5 °,45 °,90 °and saddle cut can meet the cutting needs of different pipe diameters and are suitable for pipeline installation, maintenance, and other fields
Precise Cutting: Using a metal cutting guide kit can ensure that the cut ends are neat, facilitating subsequent welding or connection work, reducing cutting errors, ensuring that the cutting surface is flat, smooth, and the size meets the requirements
Excellent Material: Pipe saddle cutting guide is made of sturdy materials that can withstand external forces and friction during the cutting process, making it easy to use
Easy to Use and Efficient: Pipe saddle template designed to be simple and user-friendly. Simply wrap the conduit around the pipe, mark along the conduit, and then remove the conduit for cutting, saving time and energy and improving work efficiency
After-Sale Service: If there is any dissatisfaction with the received goods, please take it easy . We will show you our sincere attitude and satisfactory solutions as soon as possible
Product Details| Brand: | Sthovd |
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| Model #: | Metal Cutting Guide Kit |
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| Price: | $32.48 |
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Sthovd Metal Cutting Guide Kit Includes Sizes: 1-7/8", 2-3/8", 2-7/8" Pipe Cutting Guide Cuts at 45°, 90°, 22.5°, and Saddle Cut, Steel-3Pcs
Mercer Industries 730030 Pipe Marking & Cutting Guide 2 3/8"
Product DescriptionUnique Transparent "Wrap Around and Mark" Design - This original transparent all-in-one pipe marking tool makes it easy for pipe fitters, plumbers and welders to mark pipes for cope cutting at most common angles. Simply wrap the wing around the pipe and join the sides together, then mark your selected angle using the clearly marked angle slots around the wing.
Easy 6-In-1 Maths Free Marking- Mark up pipe for cutting without the use of the welder's blue book, without any maths or extra marking. Simply wrap the pipe notcher around the pipe and make your choices pipe joining angles of 22.5, 30, 45, 60, 67.5 or 90 (cope) degrees.
Flexible and Polycarbonate Tuff - Being made from 0.4 mm clear polycarbonate makes this coping wing both super flexible and dimensionally stable, so it will not stretch, fray or warp over time. Polycarbonate is a strong plastic with a melting point of over 300 degrees Fahrenheit or 150 degrees Celsius for workshop survivability. Printing is with UV-cured and uv stable inks so will not fade or smear with time.
Easy Magnet Free Storage - Unlike bulky metal pipe saddle magnetic templates that take up room and attract loose screws, this pipe cutting guide stores flat taking up almost no room in the toolbox, or just slip this into the diary.
Stocked in the USA, UK & Australia: This Australian designed and manufactured tool is made from high quality and strong Easy Magnet Free Storage - Unlike bulky metal pipe saddle magnetic templates that take up room and attract loose screws, this pipe cutting guide stores flat taking up almost no room in the toolbox, or just slip this into the diary.
Product Details| Brand: | CLPA |
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| Model #: | 1" |
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| Size: | 1" |
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| Color: | Clear |
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| Price: | $19.95 |
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CLPA 1" Coping Wing Master: Ultimate Pipefitter and Welding Tool, Precision Pipe Saddle Template, Notcher & Cutting Guide, Ideal for Pipe Fitting - Marking & Coping Pipes from 22.5 to 90 Degrees
Mercer Industries 730030 Pipe Marking & Cutting Guide 2 3/8"
Product Description📐👷 【 Precisionflex Angle & Arc Marking Tool 】 Take the guesswork out of marking! This innovative tool lets you easily create sharp 90-degree angles and smooth curves on square or flat steel. Say goodbye to errors and enjoy precise craftsmanship with every project.
📐👷 【 All-in-One Metal Marking Tool 】 Save time and effort with a tool that combines measuring, marking, and bending functions. Whether you're working on metal, wood, or pipe, this tool helps you tackle every challenge with ease and efficiency.
📐👷 【 Pipe Angle Marking Made Easy 】 Perfect for welders and pipefitters, this tool makes marking straight lines around pipe or using a straight edge quick and accurate.
📐👷 【 Built to Last Angle Arc Marking Tool 】 Crafted from premium materials, this durable tool can handle even the toughest metalworking tasks. It's versatile enough to be used as a carpenter’s square, making it the perfect companion for any home improvement project.
📐👷 【 Boost Your Marking Welding Craftsmanship 】 Achieve excellence in metalworking and woodworking with this precision tool. Designed for maximum efficiency and accuracy, it ensures your projects meet the highest standards every time.
📐👷 【 Versatile & Easy to Use Pipe Cutting Guide 】 Ideal for DIY enthusiasts, engineers, carpenters, and decorators, this tool is perfect for round materials, 3D workpieces, and square wood. Looking for the ultimate gift for a DIY lover? This multi-angle ruler is a must-have addition to any toolbox.
Product Details| Brand: | Generic |
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| Model #: | Precisionflex Angle & Arc Marking Tool |
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| Color: | S+L |
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| Dimensions: | 11 X 3.9 X 0.1 inches (Length X Width X Height) |
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| Price: | $22.97 |
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Precisionflex Angle & Arc Marking Tool 2025 - New Square Steel Pipe Bend Welding Guide for Cutting - S+L
Mercer Industries 730030 Pipe Marking & Cutting Guide 2 3/8"
Product DescriptionCreates 4 different cutting guides at 45, 90, 22.5, and saddle cut
Save time and money with less waste and a better fit
Place template, trace template, remove template, and start cutting
Lightweight, durable, and every guide comes with a lifetime guarantee
Used for fencing, corrals, handrails, race cars, and more
Product Details| Brand: | Pipe Pro Guide |
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| Model #: | MEKIT-LG |
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| Warranty: | Parts = lifetime. |
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| Dimensions: | 5 X 4.5 X 6.25 Inches (Length X Width X Height) |
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| Price: | $41.99 |
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Pipe Pro Guide Na, MEKIT-LG, NA
Mercer Industries 730030 Pipe Marking & Cutting Guide 2 3/8"
Product DescriptionPrecision Engineering for Pipefitting & Welding: Eliminates guesswork when marking saddle notches on round pipes, ensuring seamless alignment for welding or joining pipes.
Save Hours on Every Project: Mark multiple pipes in minutes (even solo!) with the one-hand operation design—ideal for large-scale installations or DIY home upgrades.
User-Friendly Design: User-friendly operation, allowing even novice users to quickly master the tool and improve work efficiency.
Versatility Across Pipe Sizes & Applications: Adjustable templates fit nominal diameter from 20mm to 200mm (3/4'' to 8'') pipes (metal/PVC), eliminating the need for multiple tools.
DIYer-Friendly & Safe: Stop wasting time and money on imperfect pipe joints—get it right the first time.Reduces setup time and minimizes errors, allowing you to complete pipe cutting and marking tasks faster with precise results.
Product Details| Brand: | MCNULGUR |
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| Model #: | MC1818537 |
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| Size: | DN20mm - DN200mm |
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| Color: | Orange |
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| Price: | $14.99 |
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Pipe Pro Cutting Guide Kit - Saddle Joint Pipe Cutting Layout Tool for Metal Fabrication, Welding, Insulation Cutting, Pipe Fitting, and DIY Projects (Orange, DN20mm - DN200mm)
