Exploring Flanges: Types and Applications
If you’re in the piping industry, you’ve likely encountered the term “Flanges” before. But what exactly are they, and why are they so crucial in piping systems? In this comprehensive guide, we delve into the world of Flanges, exploring their types, materials, and applications.
What is a Flange?
Flanges are crucial components used to connect pipes, valves, pumps, and other equipment in piping systems, ensuring a secure and efficient flow. Unlike other types of fittings, flanges are bolted together, providing easy access for cleaning, inspection, or modification. Available in various types and sizes, such as slip-on, weld neck, blind, and socket weld flanges, they cater to diverse piping requirements. Flanges are designed to withstand high pressure and temperature conditions, making them ideal for a wide range of industrial applications, including oil and gas, petrochemical, and construction projects. At Fortune Fittings Pvt. Ltd., we offer high-quality flanges that meet stringent quality standards, ensuring reliable and leak-proof connections for your piping systems.
Materials Used in Flanges
Flanges are crucial components in piping systems, connecting pipes, valves, and equipment securely. Made from materials like stainless steel, carbon steel, alloy steel, and cast iron, flanges offer durability and corrosion resistance. Common types include slip-on, weld neck, blind, and socket weld, each suited to specific piping requirements. These materials ensure that flanges meet high-quality standards for reliable and leak-proof connections, essential in industries like oil and gas, petrochemicals, and construction.
Types of Flanges
Flanges are essential in connecting pipes, valves, pumps, and other equipment in piping systems. They come in various types, each designed for specific applications and requirements. Here are some common types of flanges:
1. Slip-On Flange: This flange slips over the pipe and is welded both inside and outside for a secure fit. It is easy to install and suitable for low-pressure applications.
2. Weld Neck Flange: Recognized for its long, tapered hub that provides reinforcement, this flange is welded directly to the pipe, making it ideal for high-pressure and high-temperature applications.
3. Blind Flange: Used to seal the end of a piping system or pressure vessel opening, this flange does not have a bore and is excellent for pressure testing and inspection.
4. Socket Weld Flange: The pipe is inserted into a socket end and then welded in place. This flange is typically used for smaller sizes and high-pressure systems.
5. Threaded Flange: Featuring a threaded bore, this flange screws onto a pipe with matching threads, eliminating the need for welding. It is suitable for low-pressure and non-critical applications.
6. Lap Joint Flange: Used in conjunction with a stub end, this flange is not welded or fixed to the pipe. It is ideal for systems requiring frequent disassembly and inspection.
7. Ring-Type Joint Flange (RTJ): This flange has a groove for a metal ring gasket, creating a tight seal. It is used in high-pressure and high-temperature applications.
8. Reducing Flange: Allows for connecting pipes of different diameters. It provides a transition in size without the need for a separate reducer fitting.
These flanges are designed to meet various industry standards, ensuring reliability and performance in diverse applications.
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Flanges: A Dominating Player in the Market
Fortune Fittings Pvt. Ltd. has established itself as a leading manufacturer and exporter of high-quality flanges in India, serving industries such as chemical processing, oil and gas, and power generation with a wide range of sizes from NPS ½ to NPS 48. Flanges are crucial for connecting pipes, valves, and pumps, ensuring secure and leak-resistant joints. Committed to stringent quality standards, Fortune Fittings Pvt. Ltd. is your trusted partner for all flange and piping needs.
ASME B16.47 Flanges Types and Applications
Flanges are crucial for connecting pipes, valves, and pumps, ensuring secure and leak-resistant joints. Our extensive product range includes:
- Slip-On Flanges
- Weld Neck Flanges
- Blind Flanges
- Socket Weld Flanges
- Orifice Flanges
- Ring-Type Joint Flanges (RTJ)
- Threaded Flanges
- Lap Joint Flanges
- Spectacle Blind Flanges
- Paddle Blind Flanges
- Ring Spacer Flanges
- Backing Ring Flanges
- Nipoflange
- Weldoflange
- Forged Flanges
- Raised Face Flanges
- Flat Face Flanges
- Series A Flanges
- Series B Flanges
- Tongue and Groove Flanges
- Male and Female Flanges
- Pipe Flanges
- Welded Flanges
- Plate Flanges
- Screwed Flanges
- Reducing Flanges
- DIN Flanges
- ANSI Flanges
- Metal Flanges
- ASME Flanges
- Long Weld Neck Flanges
- Steel lap joint Flanges
- ASTM Flanges
- Round Flanges
- Puddle Flanges
- PN Flanges
- Forged Steel Flanges
Optimizing Your Piping System with Flanges
Optimizing your piping system with flanges is crucial for ensuring efficiency, reliability, and leak-proof connections in various industrial applications. Flanges, including types such as slip-on, weld neck, blind, socket weld, threaded, lap joint, and ring-type joint (RTJ), play a pivotal role in connecting pipes, valves, and pumps. They provide robust, durable joints that withstand high pressure and temperature variations, making them indispensable in industries like chemical processing, oil and gas, and power generation. By selecting the right flange type and material, you enhance the performance and longevity of your piping system, ensuring seamless operations and reduced maintenance costs. Fortune Fittings Pvt. Ltd. offers an extensive range of high-quality flanges, designed to meet stringent quality standards and cater to diverse industrial needs.
Flanges Dimensions
Dimensions Weld Neck Flanges & Stud Bolts
ASME B16.5
OTHER DIA | NPS 1/2 – O.D. 21.3 | |||||
CLass | 150 | 300 | 600 | 900 | 1500 | 2500 |
DIA A | 30 | 38 | 38 | 38 | 38 | 43 |
DIA D | 90 | 95 | 95 | 120 | 120 | 135 |
THK B | 11.2 | 14.3 | 20.7 | 28.7 | 28.7 | 36.6 |
DIA G | 35.1 | 35.1 | 35.1 | 35.1 | 35.1 | 35.1 |
DIA K | 60.3 | 66.7 | 66.7 | 82.6 | 82.6 | 88.9 |
H | 47.6 | 52.6 | 58.4 | 66.4 | 66.4 | 79.4 |
NO. L | 4 | 4 | 4 | 4 | 4 | 4 |
DIA L | 15.9 | 15.9 | 15.9 | 22.2 | 22.2 | 22.2 |
Stud Bolts Diameter x Length | ||||||
DIA (in) | 1/2 | 1/2 | 1/2 | 3/4 | 3/4 | 3/4 |
lgth (mm) | 55 | 65 | 75 | 110 | 110 | 120 |
- IMPORTANT! please read this short article
Dimensional Tolerances of Weld Neck Flanges ASME B16.5

Dimensions Slip On Flanges & Stud Bolts
ASME B16.5
OTHER DIA | NPS 1/2 ID 22.3 | |||||
CLass | 150 | 300 | 600 | 900 | 1500 | 2500 |
DIA A | 30 | 38 | 38 | 38 | 38 | … |
DIA D | 90 | 95 | 95 | 120 | 120 | … |
THK B | 11.2 | 14.3 | 20.7 | 28.7 | 28.7 | … |
DIA G | 35.1 | 35.1 | 35.1 | 35.1 | 35.1 | … |
DIA K | 60.3 | 66.7 | 66.7 | 82.6 | 82.6 | … |
H | 15.6 | 22.6 | 28.4 | 38.4 | 38.4 | … |
NO. L | 4 | 4 | 4 | 4 | 4 | … |
DIA L | 15.9 | 15.9 | 15.9 | 22.2 | 22.2 | … |
Stud Bolts Diameter x Length | ||||||
DIA (in) | 1/2 | 1/2 | 1/2 | 3/4 | 3/4 | … |
lgth (mm) | 55 | 65 | 75 | 110 | 110 | … |
- IMPORTANT! please read this short article
Dimensional Tolerances of Weld Neck Flanges ASME B16.5
Outside Diameter * Tolerances not listed in ASME B16.5 2013≤24 = 1.6 mm (0.06 in)>24 = ±3.2 mm (±0.12 in) Inside Diameter ≤ 10 = ± 0.8 mm≥ 12 = + 1.6 mm / – 0 mm Outside Diameter of Hub ≤ 12 = + 2.4 mm / – 1.6 mm≥ 14 = ± 3.2 mm Diameter of Counterbore Same as for Inside Diameter Drilling Bolt Circle = 1.6 mmBolt Hole Spacing = ± 0.8 mm Eccentricity of Bolt Circle ≤ 2.1/2 = 0.8 mm max.≥ 3 = 1.6 mm max. Thickness ≤ 18 = + 3.2 mm / – 0≥ 20 = + 4.8 mm / – 0 Length thru Hub ≤ 18 = + 3.2 mm / – 0.8 mm≥ 20 = + 4.8 mm / – 1.6 mm Diameter of Contact Face 1.6 mm Raised Face = ± 0.8 mm6.35 mm Raised FaceTongue and Groove / Male-Female± 0.4 mmDimensions Socket Weld Flanges & Stud Bolts
ASME B16.5
OTHER DIA | NPS 1/2 ID=22.3 F=9.5 | |||||
CLass | 150 | 300 | 600 | 900 | 1500 | 2500 |
DIA A | 30 | 38 | 38 | … | 38 | … |
DIA D | 90 | 95 | 95 | … | 120 | … |
THK B | 11.2 | 14.3 | 20.7 | … | 28.7 | … |
DIA G | 35.1 | 35.1 | 35.1 | … | 35.1 | … |
DIA K | 60.3 | 66.7 | 66.7 | … | 82.6 | … |
H | 15.6 | 22.6 | 28.4 | … | 38.4 | … |
NO. L | 4 | 4 | 4 | … | 4 | … |
DIA L | 15.9 | 15.9 | 15.9 | … | 22.2 | … |
Stud Bolts Diameter x Length | ||||||
DIA (in) | 1/2 | 1/2 | 1/2 | … | 3/4 | … |
lgth (mm) | 55 | 65 | 75 | … | 110 | … |
- ID 2 = Depending on the wall thickness of the pipe, must bespecified by the purchaser.
- IMPORTANT! please read this short article
Dimensional Tolerances of Socket Weld Flanges ASME B16.5
Outside Diameter * Tolerances not listed in ASME B16.5 2013≤ 24 = 1.6 mm> 24 = ± 3.2 mm Inside Diameter ≤ 10 = ± 0.8 mm≥ 12 = + 1.6 mm / – 0 mm Outside Diameter of Hub ≤ 12 = + 2.4 mm / – 1.6 mm≥ 14 = ± 3.2 mm Diameter of Counterbore Same as for Inside Diameter Drilling Bolt Circle = 1.6 mmBolt Hole Spacing = ± 0.8 mm Eccentricity of Bolt Circle ≤ 2.1/2 = 0.8 mm max.≥ 3 = 1.6 mm max. Thickness ≤ 18 = + 3.2 mm / – 0≥ 20 = + 4.8 mm / – 0 Length thru Hub ≤ 18 = + 3.2 mm / – 0.8 mm≥ 20 = + 4.8 mm / – 1.6 mm Diameter of Contact Face 1.6 mm Raised Face = ± 0.8 mm6.35 mm Raised FaceTongue and Groove / Male-Female± 0.4 mm Studs are measured parallel to the axis (L) from the first to the threadwithout the chamfers (points). S = free threads equals 1/3 time bolt dia Hex bolts are measured from under the head to the top of de boltDimensions Lap Joint Flanges & Stud Bolts
ASME B16.5
OTHER DIA | NPS 1/2 ID=22.9 r=3 | |||||
CLass | 150 | 300 | 600 | 900 | 1500 | 2500 |
DIA A | 30 | 38 | 38 | 38 | 38 | 43 |
DIA D | 90 | 95 | 95 | 120 | 120 | 135 |
THK B | 11.2 | 14.3 | 14.3 | 22.3 | 22.3 | 30.2 |
DIA K | 60.3 | 66.7 | 66.7 | 82.6 | 82.6 | 88.9 |
H | 16 | 22 | 22 | 32 | 32 | 40 |
NO. L | 4 | 4 | 4 | 4 | 4 | 4 |
DIA L | 15.9 | 15.9 | 15.9 | 22.2 | 22.2 | 22.2 |
Stud Bolts Diameter x Length | ||||||
DIA (in) | 1/2 | 1/2 | 1/2 | 3/4 | 3/4 | 3/4 |
lgth (mm) | 55 | 65 | 75 | 110 | 110 | 120 |
- IMPORTANT! please read this short article
Dimensional Tolerances of Lap Joint Flanges ASME B16.5
Outside Diameter * Tolerances not listed in ASME B16.5 2013≤ 24 = 1.6 mm> 24 = ± 3.2 mm Inside Diameter ≤ 10 = ± 0.8 mm≥ 12 = + 1.6 mm / – 0 mm Outside Diameter of Hub ≤ 12 = + 2.4 mm / – 1.6 mm≥ 14 = ± 3.2 mm Diameter of Counterbore Same as for Inside Diameter Drilling Bolt Circle = 1.6 mmBolt Hole Spacing = ± 0.8 mm Eccentricity of Bolt Circle ≤ 2.1/2 = 0.8 mm max.≥ 3 = 1.6 mm max. Thickness ≤ 18 = + 3.2 mm / – 0≥ 20 = + 4.8 mm / – 0 Length thru Hub ≤ 18 = + 3.2 mm / – 0.8 mm≥ 20 = + 4.8 mm / – 1.6 mm Diameter of Contact Face 1.6 mm Raised Face = ± 0.8 mm6.35 mm Raised FaceTongue and Groove / Male-Female± 0.4 mm Studs are measured parallel to the axis (L) from the first to the threadwithout the chamfers (points). S = free threads equals 1/3 time bolt dia Hex bolts are measured from under the head to the top of de boltDimensions Threaded Flanges & Stud Bolts
ASME B16.5
OTHER DIA | NPS 1/2 | |||||
CLass | 150 | 300 | 600 | 900 | 1500 | 2500 |
DIA A | 30 | 38 | 38 | 38 | 38 | 43 |
DIA D | 90 | 95 | 95 | 120 | 120 | 135 |
THK B | 11.2 | 14.3 | 20.7 | 28.7 | 28.7 | 36.6 |
DIA G | 35.1 | 35.1 | 35.1 | 35.1 | 35.1 | 35.1 |
DIA K | 60.3 | 66.7 | 66.7 | 82.6 | 82.6 | 88.9 |
H | 15.6 | 22.6 | 28.4 | 38.4 | 38.4 | 46.4 |
NO. L | 4 | 4 | 4 | 4 | 4 | 4 |
DIA L | 15.9 | 15.9 | 15.9 | 22.2 | 22.2 | 22.2 |
Stud Bolts Diameter x Length | ||||||
DIA (in) | 1/2 | 1/2 | 1/2 | 3/4 | 3/4 | 3/4 |
lgth (mm) | 55 | 65 | 75 | 110 | 110 | 120 |
- IMPORTANT! please read this short article
Dimensional Tolerances of Threaded Flanges ASME B16.5
Outside Diameter * Tolerances not listed in ASME B16.5 2013≤ 24 = 1.6 mm> 24 = ± 3.2 mm Inside Diameter Within Limits on Boring Gauge Drilling Bolt Circle = 1.6 mmBolt Hole Spacing = ± 0.8 mm Eccentricity of Bolt Circle ≤ 2.1/2 = 0.8 mm max.≥ 3 = 1.6 mm max. Outside Diameter of Hub ≤ 12 = + 2.4 mm / – 1.6 mm≥ 14 = ± 3.2 mm Diameter of Counterbore Same as forInside Diameter Thickness ≤ 18 = + 3.2 mm / – 0≥ 20 = + 4.8 mm / – 0 Length thru Hub ≤ 18 = + 3.2 mm / – 0.8 mm≥ 20 = + 4.8 mm / – 1.6 mm Diameter of Contact Face 1.6 mm Raised Face = ± 0.8 mm6.35 mm Raised FaceTongue and Groove / Male-Female± 0.4 mm Studs are measured parallel to the axis (L) from the first to the threadwithout the chamfers (points). S = free threads equals 1/3 time bolt dia Hex bolts are measured from under the head to the top of de boltDimensions Blind Flanges & Stud Bolts
ASME B16.5
OTHER DIA | NPS 1/2 | |||||
CLass | 150 | 300 | 600 | 900 | 1500 | 2500 |
DIA D | 90 | 95 | 95 | 120 | 120 | 135 |
B | 11.2 | 14.3 | 20.7 | 28.7 | 28.7 | 36.6 |
DIA G | 35.1 | 35.1 | 35.1 | 35.1 | 35.1 | 35.1 |
DIA K | 60.3 | 66.7 | 66.7 | 82.6 | 82.6 | 88.9 |
NO. L | 4 | 4 | 4 | 4 | 4 | 4 |
DIA L | 15.9 | 15.9 | 15.9 | 22.2 | 22.2 | 22.2 |
Stud Bolts Diameter x Length | ||||||
DIA (in) | 1/2 | 1/2 | 1/2 | 3/4 | 3/4 | 3/4 |
lgth (mm) | 55 | 65 | 75 | 110 | 110 | 120 |
- IMPORTANT! please read this short article
Dimensional Tolerances of Blind Flanges ASME B16.5
Outside Diameter * Tolerances not listed in ASME B16.5 2013≤ 24 = 1.6 mm> 24 = ± 3.2 mm Inside Diameter not applicable Outside Diameter of Hub ≤ 12 = + 2.4 mm / – 1.6 mm≥ 14 = ± 3.2 mm Outside Diameter of Hub ≤ 12 = + 2.4 mm / – 1.6 mm≥ 14 = ± 3.2 mm Drilling Bolt Circle = 1.6 mmBolt Hole Spacing = ± 0.8 mm Eccentricity of Bolt Circle ≤ 2.1/2 = 0.8 mm max.≥ 3 = 1.6 mm max. Thickness ≤ 18 = + 3.2 mm / – 0≥ 20 = + 4.8 mm / – 0 Length thru Hub ≤ 18 = + 3.2 mm / – 0.8 mm≥ 20 = + 4.8 mm / – 1.6 mm Diameter of Contact Face 1.6 mm Raised Face = ± 0.8 mm6.35 mm Raised FaceTongue and Groove / Male-Female ± 0.4 mm Studs are measured parallel to the axis (L) from the first to the threadwithout the chamfers (points). S = free threads equals 1/3 time bolt dia Hex bolts are measured from under the head to the top of de bolt