Quick wins for a faster PC:
Repair Windows errors before they cause bigger problemsFix Now →Scan for outdated or missing drivers - takes under a minuteDriver Scan →Clear out junk files and repair common Windows errorsFree Scan →Some links on this page are affiliate links: if you buy through them we may earn a commission, at no extra cost to you.
A flange is a projecting rim, lip, or ridge on a component. Depending on its design, it can strengthen a part, provide a surface for attaching another part, or guide movement. In industrial piping, a flange is commonly used to bolt a pipe or piece of equipment to a matching component, often with a gasket between the faces.
What does a flange do?
The word “flange” describes a feature, not one universal part with one job. A flange can reinforce a component, create an attachment surface, or help guide movement; its purpose depends on the component’s design. In piping, the term usually refers to a component or rim at the end of a pipe or piece of equipment that forms part of a bolted connection.
As an Amazon Associate I earn from qualifying purchases.
Free tools Windows power users keep installed
One-click scans. No signup required.
A pipe flange makes a joint that can be assembled and, when required, separated for maintenance. Bolts draw the matching flange faces together. A gasket may sit between those faces to provide a static seal. The connection is a system: the flange, mating face, gasket, bolts, connected equipment, and assembly all affect whether the joint is suitable and leak-tight.
Flanges also appear in structural and mechanical designs, where their functions can differ from a pipe flange’s. The piping examples below explain one common industrial use; they are not a definition of every flange.
Popular on Amazon
- Read Before You Buy — No Video Output: These adapters support charging and USB 2.0 data transfer, but cannot transmit video signals. Except for standard USB webcams (which use USB data only), they are not compatible with HDMI/DisplayPort cables, video-capable USB-C hubs, or docking stations with video output.
- Convert USB-A Ports to USB-C: Designed to connect USB-C earphones, cables, flash drives, card readers, and other USB-C accessories to standard USB-A ports. Plug-and-play with no drivers or software required.
- Aluminum Alloy Housing: Built with a sturdy aluminum alloy shell that aids in heat dissipation and protects against daily wear and scratches. Designed to maintain a stable and secure connection.
- Compact & Travel-Friendly: The ultra-compact design allows the adapter to stay plugged into your device without blocking adjacent ports or adding bulk, reducing wear and tear on your original USB ports.
- 12-Month Warranty: Backed by a 12-month manufacturer warranty for peace of mind. Designed to meet strict quality control standards for reliable everyday performance.
How does a pipe flange connection work?
Two compatible flanges are positioned face to face and joined with bolts. Where the joint design calls for a gasket, it is placed at the sealing interface; tightening the bolting compresses the joint components to form the connection. The exact assembly requirements depend on the flange and joint design, service conditions, and applicable procedures.
A flange connection can be useful when pipes or equipment need to be joined in a way that allows access for maintenance. But bolting parts together does not, by itself, establish that the connection is safe or leak-tight. A correctly specified joint needs compatible components and an appropriate assembly process.
ASME’s PCC-1 guidance addresses pressure-boundary bolted flange joint assemblies using ring-type gaskets located entirely within the bolt-hole circle. It also covers troubleshooting joints that do not provide leak-tight performance and guidance on training and qualification for bolted-joint assemblers. That scope illustrates why a flange should be understood as part of an engineered joint, rather than as a standalone guarantee of sealing.
What are the types of pipe flanges?
Common flange names describe either how a flange connects to the pipe or the shape of its sealing face. Those are separate classifications: a connection type does not tell you the face type, and a face type does not tell you how the flange is attached.
Also popular on Amazon
- 5-in-1 USB-C Hub: Experience comprehensive connectivity featuring a Power Delivery input, two USB-A 2.0 ports, a USB-A 3.0 port, and an HDMI port. (Note: The USB-C power delivery input port is only for connecting an external wall charger to power your laptop and cannot power peripheral devices.)
- 90W Pass-Through Charging: Achieve optimal charging with 90W pass-through power to your laptop, supported by a total input of 100W, with the hub reserving 10W for operational efficiency. (Note: Wall charger not included.)
- Quick Data Transfers: Accelerate your productivity with rapid data transfers using a high-speed 5Gbps USB 3.0 port and two 480Mbps USB 2.0 ports.
- 4K HDMI Display: Enhance your visual experience with a hub capable of delivering 4K resolution at 30Hz in both mirror and extend modes. Please note that this hub is compatible with MacBook (macOS 12 and newer), Windows 10 and 11, ChromeOS, and laptops equipped with DP Alt Mode and Power Delivery. Note: This device is not compatible with Linux.
- What You Get: Anker USB-C Hub (5-in-1, 4K HDMI), welcome guide, 18-month warranty, and our friendly customer service.
Connection and configuration types
| Type | What it describes |
|---|---|
| Weld neck | Has a tapered neck and connects to the pipe with a butt weld. |
| Slip-on | Slides over the pipe and is attached with fillet welds. |
| Blind | Closes an opening rather than connecting two open pipe ends. |
| Socket-weld | Accepts the pipe in a socket. |
| Lap-joint | Uses a stub end as part of the connection. |
| Threaded | Screws onto threaded pipe. |
These descriptions provide basic orientation, as summarized in API International’s supplier guide; they are not a substitute for the design code or specification that applies to a real installation. The names indicate different connection arrangements, so a reader should not treat two flange types as interchangeable just because they serve the same general purpose.
Sealing-face types
| Face type | What the name describes | Selection consideration |
|---|---|---|
| Flat-face | A flat mating surface. | The SAPIA guideline says flat-face flanges are used with other flat-face flanges and are mainly used with cast-iron equipment, valves, and special equipment. Treat that as guidance from that document, not a universal rule. |
| Raised-face | A raised sealing area on the flange face. | SAPIA describes this face as widely used. The correct gasket and matching joint details still depend on the application. |
| Tongue-and-groove | Mating faces with complementary tongue and groove features. | Compatibility of the two mating faces and the specified joint design matters. |
| Ring-joint | A face designed for a ring-type gasket arrangement. | The gasket and face must match the applicable design and service requirements. |
Face geometry affects the gasket interface, so selecting a flange based only on its nominal pipe size or connection style is not enough. A face that does not match the mating component or specified gasket arrangement may not form the intended joint.
Recommended Free Tools
What is the difference between a raised-face and flat-face flange?
A raised-face flange has a raised sealing area, while a flat-face flange has a flat mating surface. The distinction is about the face geometry and gasket interface, not how the flange attaches to the pipe.
The SAPIA guideline describes raised-face flanges as widely used, and says flat-face flanges are used with other flat-face flanges and mainly with cast-iron equipment, valves, and special equipment. Those are statements in SAPIA’s August 2021 industry guideline, not universal selection instructions. For a specific joint, use the applicable design standard and equipment requirements to establish compatible faces and gasket details.
Also popular on Amazon
- Sleek 7-in-1 USB-C Hub: Features an HDMI port, two USB-A 3.0 ports, and a USB-C data port, each providing 5Gbps transfer speeds. It also includes a USB-C PD input port for charging up to 100W and dual SD and TF card slots, all in a compact design.
- Flawless 4K@60Hz Video with HDMI: Delivers exceptional clarity and smoothness with its 4K@60Hz HDMI port, making it ideal for high-definition presentations and entertainment. (Note: Only the HDMI port supports video projection; the USB-C port is for data transfer only.)
- Double Up on Efficiency: The two USB-A 3.0 ports and a USB-C port support a fast 5Gbps data rate, significantly boosting your transfer speeds and improving productivity.
- Fast and Reliable 85W Charging: Offers high-capacity, speedy charging for laptops up to 85W, so you spend less time tethered to an outlet and more time being productive.
- What You Get: Anker USB-C Hub (7-in-1), welcome guide, 18-month warranty, and our friendly customer service.
What do flange pressure classes mean?
A pressure class is not a universal pressure value that can be read without context. ASME B16.5 sets pressure-temperature ratings alongside requirements for materials and other flange details, so the allowable rating depends on the relevant material and temperature rather than the class number alone.
ASME’s B16.5 product page describes coverage of pipe flanges and flanged fittings from NPS 1/2 through NPS 24. Within that scope, it lists classes 150, 300, 400, 600, 900, and 1500 for the size range, and class 2500 through NPS 12. These are standard scope details, not a conversion table from class to one operating pressure. Do not infer an allowable pressure from a class label without the applicable material, temperature, size, and code context.
Which flange standards apply?
Flange standards define the scope and requirements for particular products and sizes; there is not one universal flange size system. ASME’s standards committee listing gives the current edition dates and scope labels for two relevant standards.
| Standard | Scope stated by ASME | Edition information |
|---|---|---|
| ASME B16.5 | Pipe flanges and flanged fittings, NPS 1/2 through NPS 24; ASME’s product page also describes pressure-temperature ratings, materials, dimensions, tolerances, marking, testing, and methods of designating openings. | ASME’s committee page lists B16.5-2025, issued May 30, 2025. The product page with the scope details is labeled for the 2017 edition. |
| ASME B16.47 | Large-diameter steel flanges, NPS 26 through NPS 60. | ASME’s committee page lists B16.47-2025, issued May 30, 2025. |
ASME describes B16.5 as covering pressure-temperature ratings, materials, dimensions, tolerances, marking, testing, and opening designations. It also says the standard includes recommendations and requirements related to bolting, gaskets, and flange joints, and is used alongside other B16 standards and pressure-equipment or piping codes. The governing code, jurisdiction, and adopted edition depend on the application; confirm them for the installation rather than assuming that a standard title alone settles every requirement.
Also popular on Amazon
- Dual Converters, Infinite Potential：Includes 2× USB C male to USB A female adapters and 2× USB A male to USB C female adapters. Perfect for a wide range of uses—tablets with Bluetooth keyboards, expand USB ports on macbook, and more. Two different converters for all your daily needs
- Next-Level 10Gbps & 3A Charging: No more slow 480Mbps, this usb to usb c adapter has a transfer speed of up to 10Gbps, allowing you to do more transferring in less time. This usb adapter fits both USB A and USB C charger, supporting up to 3A fast charging
- Upgraded Exquisite Craftsmanship: With an aluminum alloy housing and metal connector, the usbc to usb adapter is extremely durable and sturdy. Rigorously tested to withstand more than 10,000 times of plugging and unplugging, ensuring long-lasting performance
- Widely Compatible: Transform any USB-C port into a USB-A port and USB-A port into a USB-C port, and connect up a wide range of USB-C(including MacBook, iPad Pro/Air/Mini, iPhone models with USB C ports, Samsung Galaxy series, and Google Pixel series. ) and USB A devices(including external hard drives, phones, mice, printers, and more)
- Please Note: To reach 10Gbps speed, keep the cable under 3.3 ft. For USB A Male to USB C adapters, try flipping the USB C connector. USB C Male to USB A adapters support bidirectional 10Gbps transfer within 3.3 ft
How do you choose a flange for a piping system?
Flange selection is a system decision: the part must suit the service and connect correctly to the other components. A product description or familiar type name alone cannot establish that fit.
- Identify the service. Establish the fluid or other service conditions, including the relevant pressure and temperature requirements.
- Confirm material compatibility. The flange material must suit the service and the connected equipment under the governing design requirements.
- Verify size and standard. Confirm the nominal size and the applicable standard, including whether the flange is within the stated scope of that standard.
- Match the connection arrangement. Determine how the flange connects to the pipe or equipment—such as by butt weld, fillet weld, socket, lap-joint arrangement, or threads—and whether the arrangement suits fabrication and maintenance needs.
- Match the sealing faces and gasket. Check the mating face geometry and the gasket specification together. Gasket selection depends on fluid, pressure, temperature, material, and connected equipment, according to the SAPIA guideline.
- Follow the governing assembly requirements. Use the applicable code and qualified procedures for bolting and joint assembly. Component labels alone do not establish that the finished joint will seal.
For a real installation, the jurisdiction, application, service conditions, governing code, and adopted edition all matter. A qualified engineering review and applicable assembly procedures are more appropriate than relying on a generic definition to specify a pressure-boundary joint.
Crashes, No Sound, or Screen Glitches?
Random freezes, missing sound and display glitches usually trace back to one bad driver. Find and replace yours safely.Free scan · under a minutePC Slower Than It Used to Be?
A free scan shows the junk files, broken settings and background clutter dragging Windows down - then fixes them in one click.Free scan · Windows 10 & 11Why can’t you choose a flange by its name alone?
Names such as “slip-on,” “weld neck,” or “raised-face” each describe only part of the design. The connection name explains how a flange joins to pipe or whether it closes an opening; the face name describes the sealing interface. Neither name, by itself, establishes material suitability, pressure-temperature rating, size compatibility, gasket choice, or compliance with the governing standard.
Likewise, a pressure class without material and temperature context is not enough to determine an allowable operating pressure. A reliable selection has to account for the whole joint and its operating conditions, not just one label on a flange.
Also popular on Amazon
- 5-in-1 Connectivity: Equipped with a 4K HDMI port, a 5 Gbps USB-C data port, two 5 Gbps USB-A ports, and a USB C 100W PD-IN port. Note: The USB C 100W PD-IN port supports only charging and does not support data transfer devices such as headphones or speakers.
- Powerful Pass-Through Charging: Supports up to 85W pass-through charging so you can power up your laptop while you use the hub. Note: Pass-through charging requires a charger (not included). Note: To achieve full power for iPad, we recommend using a 45W wall charger.
- Transfer Files in Seconds: Move files to and from your laptop at speeds of up to 5 Gbps via the USB-C and USB-A data ports. Note: The USB C 5Gbps Data port does not support video output.
- HD Display: Connect to the HDMI port to stream or mirror content to an external monitor in resolutions of up to 4K@30Hz. Note: The USB-C ports do not support video output.
- What You Get: Anker 332 USB-C Hub (5-in-1), welcome guide, our worry-free 18-month warranty, and friendly customer service.
What is a flange, in one sentence?
A flange is a projecting rim, lip, or ridge that can reinforce, attach, or guide a component; in piping, it commonly forms part of a bolted connection between pipes or equipment, often with a gasket at the mating faces.
Frequently Asked Questions
Can two flanges with the same nominal pipe size fit together?
Not necessarily. Nominal size is only one compatibility detail; the applicable standard, pressure class, face, material, and connection arrangement also need to match the intended joint.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
Does a flange always need a gasket?
No single answer applies to every flange design. A gasket may provide the static seal between mating faces, but the specified joint design determines whether one is used and which type is appropriate.
What does NPS mean in a flange standard?
NPS is the nominal pipe size designation used in the cited ASME standard scopes. It identifies a size designation, not a complete description of flange dimensions or pressure capability.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
