The Different Types of Flanges and Their Use

Flanges are elements that are used for interconnecting pipes as well as attaching pipes to valves, pumps, and other related components. Commonly used for a variety of plumbing applications, there are numerous flange designs that one may take advantage of for varying requirements. Each flange will typically differ in its design, materials, testing, and certification, allowing them to benefit certain needs. In this blog, we will discuss the primary types, allowing you to have a better understanding of all the available options.

Steel Flanges

Steel flanges are often built to one of two standards, those of which are the ASME 16.5 and ASME B16.47 standard. The latter covers two series, the A and B series, and the A series is known for being heavier and thicker than their counterpart while exhibiting the same pressure and size. Series B steel flanges, meanwhile, are relied on for refurbishment applications in particular. If steel flanges are to be implemented within hydraulic systems, they will often be governed under SAE standards.

Aluminum Flanges

Aluminum flanges are typically cast components, and they may be procured in similar forms as compared to steel flanges. Oftentimes, aluminum flanges will facilitate the construction and assembly of aluminum handrails, and such flanges can be weldable or clamp-on types. For the welding of aluminum flanges, a MIG or TIG process will be carried out.

Threaded Flanges

For low- or medium-pressure applications, threaded flanges are an optimal choice. As compared to other flange types, threaded flanges are desirable for their ease of field installation. Furthermore, they are also known for being cost-efficient and easy to transport.

Welded Flanges

Welded flanges, or weld-on flanges, are components that come in the form of lapped, weld neck, socket weld, ring-type joint, and slip-on variations. Each subtype differs in its capabilities, all being rated by pressure and temperature. As an example of their individual uses, lapped flanges are a type that can freely spin, typically being used in assemblies where there is a need for frequent disconnections. To establish welded flanges on an assembly, butt welding or socket welding is carried out. Socket welding will often produce components that are weaker, though they are often preferred over threaded flanges for high-end applications.

Plastic Flanges

While many of the aforementioned components are made of metallic materials or similar substances, plastic flanges are an option that may be used as well. Such flanges are often used for plastic or steel piping, while some are specifically designed for use in water. For PVC piping, flanges will be constructed to meet Schedule 40 and 80 dimensions. If reinforcement is required, fiber may be added to the flange.

Miscellaneous Flanges

While all the aforementioned types are the primary variations that are commonly used, there are other options that one may acquire to optimally fulfill their needs. Roof flanges are an example of these miscellaneous types, those of which are used in vent stacks that need to pass through the shingles of a roof. Microwave flanges are another example, utilized for waveguide applications. Finally, applications related to automotive and aerospace industries may necessitate the use of specialized products.


Whether you require steel flanges, aluminum flanges, or other various types, there is no better alternative to Paragon Purchasing. Paragon Purchasing is a premier supplier of aviation, NSN, and electronic parts that serve a diverse set of applications. Take the time to explore our expansive catalogs of parts, and you may utilize our RFQ service to request quotes for your comparisons with ease. With our steadfast commitment to providing customers with parts of the highest quality and caliber, we proudly operate with AS9120B, ISO 9001:2015, and FAA AC 00-56B certification and accreditation. Give us a call or email at your earliest convenience, and see how we can fulfill all your part needs with time and cost savings. 


November 20, 2023

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