Stainless Steel Flanges Supplier & Manufacturer in India
Kalpaturu Piping Solutions is a leading stainless steel flange supplier and manufacturer in large quantities with a wide range of shapes, sizes and specifications to suit various and different needs of customers. With clients located across the world, Kalpataru Piping Solutions has established a good reputation for providing high-quality and dependable flanges that are in line with the international standards.
Our flanges division has an in-house fully integrated forge facility that can produce any type of pipe fitting, including stainless steel pipe flanges and butt welding fittings, and is also compliant with standards such as ASME/ANSI, EN, DIN, AFNOR, AWWA, GOST, BS, JIS, AS, MSS, SA and UNI. We also produce precision forged bars in order to complement our flange products.
Kalpataru Piping Solutions manufactures stainless steel flanges of sizes as small as 1/2 inch and 40 and above to serve the entire gamut of industry. A strict quality management system with several certifications and approvals supports our operations and makes sure that they adhere to the highest standards of the international standards. The certifications help us to provide our flanges to key industries such as oil and gas, petrochemical, power generation, and water treatment and marine sectors.
As a company that believes in being precise in engineering and long-lasting and satisfying customers, Kalpataru Piping Solutions remains a reliable company in terms of offering high-performance piping solutions that offer products that ensure reliability and efficiency in different applications in the world.
- What is Stainless Steel Flanges
- Stainless Steel Flanges Material Grades
- Specification of Stainless Steel Flanges
- SS Flanges Types
- Chemical Composition for F304 and F316 SS Flange
- Mechanical Properties of Stainless Steel Flanges
- Heat Treatment for SS Flange
- Welding Repair Requirements for Stainless Flange
- Applications of Stainless Steel Flanges
- People Ask About Stainless Steel Flanges Supplier
What is Stainless Steel Flanges
Stainless Steel Flanges (SS Flanges) are specialized mechanical components crafted from stainless steel, designed to join two sections of pipe or connect piping to equipment securely. They provide a strong, leak-proof junction and are widely used in piping systems across multiple industries.
Commonly, SS flanges are manufactured following standards such as ASTM A182, with popular grades including F304/L and F316/L. These flanges come in a variety of pressure ratings, typically ranging from Class 150 to Class 2500, making them suitable for both low and high-pressure applications. Stainless steel is favored over carbon steel due to its excellent corrosion resistance, durability, and polished appearance.
Key Stainless Steel Grades for Flanges:
- 304 Stainless Steel: Ideal for general-purpose applications; offers reliable corrosion resistance.
- 316 Stainless Steel: Provides superior resistance to corrosion, especially in harsh or marine environments.
- 410 Stainless Steel: Martensitic grade with high strength, often used where mechanical toughness is critical.
SS flanges are essential in industries such as chemical processing, oil and gas, water treatment, and food processing, where reliability, longevity, and resistance to corrosion are paramount. Their versatility and strength make them a crucial component in modern piping solutions.
Stainless Steel Flanges Material Grades
Specification of Stainless Steel Flanges
| Specification | Details |
| Material | Stainless Steel (SS) |
| Common Grades | SS 304, SS 304L, SS 316, SS 316L, SS 410 |
| Standards | ASTM A182, ASME B16.5, EN 1092, DIN, JIS, MSS, BS |
| Flange Types | Weld Neck, Slip-On, Blind, Socket Weld, Threaded, Lap Joint |
| Size Range | ½” to 40” (DN 15 – DN 1000) |
| Pressure Rating | Class 150, 300, 400, 600, 900, 1500, 2500 |
| Temperature Range | -50°C to 550°C (depending on grade and application) |
| Surface Finish | Smooth/Machined, RF (Raised Face), RTJ (Ring Type Joint), FF (Flat Face) |
| Applications | Oil & Gas, Petrochemical, Water Treatment, Food Processing, Marine, Chemical |
| Features | Corrosion resistant, durable, leak-proof, high strength, aesthetic finish |
SS Flanges Types
Slip On Flange
Socket Weld Flange
Stainless Steel 304 / 304L Flanges
Stainless Steel 310 / 310S Flanges
Stainless Steel 316 / 316L / 316Ti Flanges
Threaded Pipe Flange
Weld Neck Flange
Blind Pipe Flange
Lap Joint Flange
Chemical Composition for F304 and F316 SS Flange
| Grade/Identification Symbol | UNS Designation | Carbon | Manganese | Phosphorus | Sulfur | Silicon | Nickel | Chromium | Molybdenum | Columbium | Titanium | Other Elements |
| Low Alloy Steels | ||||||||||||
| F5C | K41455 | 0.15 | 0.30–0.60 | 0.030 | 0.030 | 0.50 | 4.0–6.0 | 0.44–0.65 | … | … | … | … |
| F9 | K90941 | 0.15 | 0.30–0.60 | 0.030 | 0.030 | 0.50–1.00 | … | 8.0–10.0 | 0.90–1.10 | … | … | … |
| F91 | K90941 | 0.08–0.12 | 0.30–0.60 | 0.020 | 0.010 | 0.20–0.50 | 0.40 | 8.0–9.5 | 0.85–1.05 | 0.06–0.10 | N 0.03–0.07, Al 0.02, Ti 0.01, Zr 0.01 | V 0.15–0.25 |
| F92 | K92460 | 0.07–0.13 | 0.30–0.60 | 0.020 | 0.010 | 0.50 | 0.40 | 8.50–9.50 | 0.30–0.60 | 0.04–0.09 | N 0.030–0.070, Al 0.02, Ti 0.01, Zr 0.01 | W 1.50–2.00, B 0.007–0.015 |
| F11, Class 1 | K11597 | 0.05–0.15 | 0.30–0.60 | 0.030 | 0.030 | 0.50–1.00 | … | 1.00–1.50 | 0.44–0.65 | … | … | … |
| F11, Class 2 | K11572 | 0.10–0.20 | 0.30–0.80 | 0.040 | 0.040 | 0.50–1.00 | … | 1.00–1.50 | 0.44–0.65 | … | … | … |
| F11, Class 3 | K11572 | 0.10–0.20 | 0.30–0.80 | 0.040 | 0.040 | 0.50–1.00 | … | 1.00–1.50 | 0.44–0.65 | … | … | … |
| F12, Class 1 | K11562 | 0.05–0.15 | 0.30–0.60 | 0.045 | 0.045 | 0.50 max | … | 0.80–1.25 | 0.44–0.65 | … | … | … |
| F12, Class 2 | K11564 | 0.10–0.20 | 0.30–0.80 | 0.040 | 0.040 | 0.10–0.60 | … | 0.80–1.25 | 0.44–0.65 | … | … | … |
| F21 | K31545 | 0.05–0.15 | 0.30–0.60 | 0.040 | 0.040 | 0.50 max | … | 2.7–3.3 | 0.80–1.06 | … | … | … |
| F22, Class 1 | K21590 | 0.05–0.15 | 0.30–0.60 | 0.040 | 0.040 | 0.50 | … | 2.00–2.50 | 0.87–1.13 | … | … | … |
| F22, Class 3 | K21590 | 0.05–0.15 | 0.30–0.60 | 0.040 | 0.040 | 0.50 | … | 2.00–2.50 | 0.87–1.13 | … | … | … |
| Austenitic Stainless Steels | ||||||||||||
| F304 | S30400 | 0.080 | 2.00 | 0.045 | 0.030 | 1.00 | 8.0–11.0 | 18.0–20.0 | … | … | … | N 0.10 |
| F304L | S30403 | 0.030 | 2.00 | 0.045 | 0.030 | 1.00 | 8.0–13.0 | 18.0–20.0 | … | … | … | N 0.10 |
| F316 | S31600 | 0.080 | 2.00 | 0.045 | 0.030 | 1.00 | 10.0–14.0 | 16.0–18.0 | 2.00–3.00 | … | … | N 0.10 |
| F316L | S31603 | 0.030 | 2.00 | 0.045 | 0.030 | 1.00 | 10.0–15.0 | 16.0–18.0 | 2.00–3.00 | … | … | N 0.10 |
| F321 | S32100 | 0.080 | 2.00 | 0.045 | 0.030 | 1.00 | 9.0–12.0 | 17.0–19.0 | … | … | … | … |
Mechanical Properties of Stainless Steel Flanges
| Grade Symbol | Tensile Strength, min, ksi [MPa] | Yield Strength, min, ksi [MPa] | Elongation in 2 in. [50 mm] or 4D, min, % | Reduction of Area, min, % | Brinell Hardness Number, HBW, unless otherwise indicated |
| Low Alloy Steels | |||||
| F5 | 70 [485] | 40 [275] | 20 | 35 | 143-217 |
| F9 | 85 [585] | 55 [380] | 20 | 40 | 179-217 |
| F91 | 90 [620] | 60 [415] | 20 | 40 | 190-248 |
| F92 | 90 [620] | 64 [440] | 20 | 45 | 269 max |
| F11, Class 1 | 60 [415] | 30 [205] | 20 | 45 | 121-174 |
| F11, Class 2 | 70 [485] | 40 [275] | 20 | 30 | 143-207 |
| F11, Class 3 | 75 [515] | 45 [310] | 20 | 30 | 156-207 |
| F12, Class 1 | 60 [415] | 32 [220] | 20 | 45 | 121-174 |
| F12, Class 2 | 70 [485] | 40 [275] | 20 | 30 | 143-207 |
| F21 | 75 [515] | 45 [310] | 20 | 30 | 156-207 |
| F22, Class 1 | 60 [415] | 30 [205] | 20 | 35 | 170 max |
| F22, Class 3 | 75 [515] | 45 [310] | 20 | 30 | 156-207 |
| Austenitic Stainless Steels | |||||
| F304 | 75 [515] | 30 [205] | 30 | 50 | … |
| F304L | 70 [485] | 25 [170] | 30 | 50 | … |
| F316 | 75 [515] | 30 [205] | 30 | 50 | … |
| F316L | 70 [485] | 25 [170] | 30 | 50 | … |
| F321 | 75 [515] | 30 [205] | 30 | 50 | … |
Heat Treatment for SS Flange
| Grade | Heat Treat Type | Austenitizing/ Solutioning Temperature, Minimum or Range, °F [°C] | Cooling Media | Quenching Cool Below °F [°C] | Tempering, Temperature, Minimum or Range, °F [°C] |
| Low Alloy Steels | |||||
| F5 | anneal | 1750 [955] | furnace cool | B | B |
| F5 | normalize and temper | 1750 [955] | air cool | B | 1250 [675] |
| F9 | anneal | 1750 [955] | furnace cool | B | B |
| F9 | normalize and temper | 1750 [955] | cool or liquid | B | 1250 [675] |
| F91 | normalize and temper or quench and temper | 1900-1975 [1040-1080] | air cool accelerated air | B | 1350-1470 [730-800] |
| F92 | normalize and temper | 1900-1975 [1040-1080] | air cool | B | 1350-1470 [730-800] |
| F11, Class 1, 2, 3 | anneal | 1650 [900] | furnace cool | B | B |
| F11, Class 1, 2, 3 | normalize and temper | 1650 [900] | air cool | B | 1150 [620] |
| F12, Class 1, 2 | anneal | 1650 [900] | furnace cool | B | B |
| F12, Class 1, 2 | normalize and temper | 1650 [900] | air cool | B | 1150 [620] |
| F21 | anneal | 1750 [955] | furnace cool | B | B |
| F21 | normalize and temper | 1750 [955] | air cool | B | 1250 [675] |
| F22, Class 1, 3 | anneal | 1650 [900] | furnace cool | B | B |
| F22, Class 1, 3 | normalize and temper | 1650 [900] | air cool | B | 1250 [675] |
| Austenitic Stainless Steels | |||||
| F304 | solution treat and quench | 1900 [1040] | liquidⁱ | 500 [260] | B |
| F304L | solution treat and quench | 1900 [1040] | liquidⁱ | 500 [260] | B |
| F316 | solution treat and quench | 1900 [1040] | liquidⁱ | 500 [260] | B |
| F316L | solution treat and quench | 1900 [1040] | liquidⁱ | 500 [260] | B |
| F321 | solution treat and quench | 1900 [1040] | liquidⁱ | 500 [260] | B |
Welding Repair Requirements for Stainless Flange
| Grade Symbol | Electrodes | Recommended Preheat and Interpass Temperature Range, °F [°C] | Post Weld Heat-Treatment Temperature Minimum or Range, °F [°C] |
| Austenitic Stainless Steels | |||
| F304 | E 308-15 or 16 | NR | 1900 [1040] + WQ |
| F304L | E 308L-15 or 16 | NR | 1900 [1040] + WQ |
| F316 | E 316-15 or 16 | NR | 1900 [1040] + WQ |
| F316L | E 316L-15 or 16 | NR | 1900 [1040] + WQ |
| F321 | E 347-15 or 16 | NR | 1900 [1040] + WQ |
- A. Except for Grades F91, F92, F93, F911, F122, F47, F48 and F49, electrodes shall comply with AWS Specification A5.4/A5.4M, A5.5/ A5.5M, A5.9/ A5.9M, A5.11/ A5.11M, A5.14/ A5.14M, A5.23/ A5.23M, or A5.28/ A5.28M.
- C. All repairs in F91 shall be made with one of following welding processes and consumables: SMAW, A5.5/ A5.5M E90XX-B9; SAW, A5.23/ A5.23M EB9 + flux; GTAW.
- D. All repairs in F92, F93, F911 and F122, shall be made using welding consumables meeting the chemical requirements for the grade in Table 2.
- G. WQ = water quench.
- NR = Not Required.
Applications of Stainless Steel Flanges
- Oil & Gas Industry: Pipelines, refineries, and offshore platforms.
- Petrochemical & Chemical Plants: High-temperature and corrosive fluid systems.
- Water Treatment Plants: Drinking water, wastewater, and desalination plants.
- Marine & Shipbuilding: Piping systems exposed to seawater.
- Food & Beverage Industry: Hygienic piping systems requiring corrosion-free materials.
- Power Generation: Steam, gas, and nuclear power plants for high-pressure connections