Carbon Steel Flanges
The most common material grade in use today is A105 forged carbon steel, with sizes ranging from 1/2“ – 24” in ASME B16.5, 26” – 60” in ASME B16.47, and 26” – 96” in B16.1 (for temperatures ranging from ambient up to 1,000 Fahrenheit and pressure between 20 – 6,170 psi). The wide temperature and pressure range makes carbon steel flanges an attractive solution for several industrial applications, and have proven to be one of the least expensive pricing options.
Modern carbon is a common steel with carbon content up to 2.1% by weight and primarily alloyed with iron. The term “carbon steel” may also be used to call out steel which does not have a large amount of chromium or nickel. The carbon content can vary for A105 with a maximum allowable of 0.35 as a percentage composition. As the carbon content increases, the steel hardens and increases in strength through heat treatment processes. Many common treatment techniques in the industry are quenching, tempering, and normalizing. As carbon steel is treated, it become less ductile and brittle. This makes it slightly more difficult to shape and weld, however the trade off in field service is often considered worth the extra effort to form the necessary weld seals.
For trace elements, no alloy element (minimum content) is required, specifically in reference to molybdenum, nickel, chromium, titanium, and vanadium.
For more detail, the chemical composition of A105 carbon steel pipe flanges is as follows
Other Carbon Steel Flanges
Mechanical requirements are as follows. Please note the tensile and yield strength requirements are minimums which can be surpassed as desired.
We also offer variants of carbon steel flanges which would traditionally be made in ASTM A105.
Options made from plate include A515-70, A516-70, and both in the normalized condition. These are typically used to make line blank style flanges per ASME B16.48. In addition, we have A36 plate and A285 Grade C plate when the superior overall properties of 515/516 are less of a concern. You will often find A36 plate steel used for smaller waterworks type flanges, as well as custom ring and disc flanges made for one-off applications.
If your application calls for low temperature service, consider A350 LF2 forged carbon flanges (with Charpy V-Notch Impact Tests at -50°F) or the superior LF3 (CVNs at -150°F). These are very similar to A105 in most ways, but are rated for colder ambient utilization.
Distinguishing Forged Steel Flanges from Cast Iron Flanges
Manufacturing Costs: The forging process tends to be more costly than cast iron.
Complex Profiles: Cast iron can be molded to accommodate intricate and complex shapes.
Uniformity: Forging results in flanges less likely to have irregularities or deformities.
Application: Cast iron flanges are primarily utilized for non-pressure pipelines, whereas forged steel flanges are preferred for high-pressure pipelines.
Precision: High-precision cast iron flanges are produced using centrifugal machines, surpassing standard cast flanges.
Cut and Strength: Forged steel flanges are more easily cut and possess higher tensile strength.
Performance: Overall, forged steel outperforms cast iron flanges due to its superior shape and lower carbon content, which reduces susceptibility to rust.
Products
Texas Flange stocks a wide variety of flanges in all sizes and specifications.
ANSI Flanges
ASME Flanges
AWWA Flanges
Pipe Flanges
Industrial Flanges
Oil & Gas Industry Flanges
Custom Flanges
Petrochemical Flanges
Texas Waterworks Flanges
Ring Joint Flanges
Large Industry Standard Flanges
Metric System Flanges
Plumbing And Mechanical Industries Flanges
Industrial Pumps, Valves And Vessels
Manufacturing Industries Flanges
Heating Systems Industries Flanges
Flange Food And Beverage Industries Flanges
Frequently Asked Questions (FAQs)
The difference between a lap joint flange and a slip-on flange lies in their design and functionality. A lap joint flange consists of two parts: a stub end, which is welded to the pipe, and a loose backing flange that can rotate freely around it.
In contrast, a slip-on flange is a single-piece component that slides over the pipe and is welded in place, providing a simpler and more cost-effective connection. Slip-on flanges are commonly used in low-pressure applications where frequent dismantling is not required.
The difference between a swivel flange and a lap joint flange is that a swivel flange consists of two separate components: a rotating ring flange and a welded hub or collar that is attached to the pipe.
A lap joint flange also has two parts, but it uses a stub end rather than a welded hub, and its backing flange is loose rather than fully rotating like a swivel flange.
Lap joint flanges are not recommended for high-pressure applications because the design does not provide the same strength or seal integrity as other flanges, such as welded or slip-on flanges, in high-pressure environments.
In applications where there is severe vibration or significant movement (such as in machinery or dynamic systems), lap joint flanges may not provide the necessary seal integrity or stability, as the loose flange may shift or loosen under intense vibration.
Weld the stub end (a part of the lap joint flange) securely onto the pipe using the appropriate welding method. Slip the loose flange over the stub end. The loose flange can rotate, allowing you to align it with the bolt holes on the other side of the pipe or flange.
Position the flange so that it fits over the stub end with the bolt holes properly aligned with the corresponding holes on the other flange.
Insert the bolts through the aligned holes of both flanges and tighten them evenly using the specified torque, ensuring a secure connection.
