Stainless Steel Flanges
Introduction & Importance
Stainless Steel Flanges are critical components used to connect pipes, valves, pumps, and other equipment in a piping system, ensuring both strength and leak-proof performance. Designed for ease of installation and removal, flanges allow quick access for cleaning, inspection, or modification of pipelines, making them indispensable in industries that demand precision and reliability. Their robust construction, combined with the inherent properties of stainless steel, makes them resistant to corrosion, high pressure, and extreme temperatures, ensuring long service life in even the harshest operating conditions.
Material Grades & Properties
These flanges are commonly manufactured from stainless steel grades such as A182 F304/304L, F316/316L, Duplex 2205, and Super Duplex 2507, offering excellent corrosion resistance against a wide range of chemicals, seawater, and aggressive media. Each grade has specific advantages—304 for general use, 316 for enhanced resistance to chlorides, and Duplex/Super Duplex for exceptional strength and stress corrosion cracking resistance. The non-reactive nature of stainless steel also ensures hygienic performance, which is why these flanges are widely adopted in food processing, pharmaceuticals, petrochemicals, oil & gas, and marine industries.
Types, Standards & Applications
Stainless Steel Flanges are available in multiple types, including Weld Neck, Slip On, Blind, Socket Weld, Threaded, and Lap Joint, each designed to meet distinct installation and operational needs. They are manufactured in compliance with international standards such as ANSI/ASME, DIN, EN, and BS, ensuring global compatibility and reliability. Their versatility makes them suitable for high-pressure pipelines, offshore structures, chemical plants, power generation facilities, and water treatment systems. With superior strength, precision machining, and durability, stainless steel flanges play a vital role in maintaining secure connections and smooth operations across a wide spectrum of industrial applications.
Stainless Steel Flanges – Specifications & Details
Specifications & Details
We manufacture and export a complete range of Stainless Steel Flanges in various face types such as Raised Face (RF), Flat Face (FF), Ring-Type Joint (RTJ), Lap Joint Face (LJF), Male & Female (M&F), and Tongue & Groove (T&G). These flanges are precision-engineered to meet diverse industrial requirements, ensuring leak-proof connections, durability, and long service life in high-pressure and corrosive environments.
Material Grades & Manufacturing
Standard: ASTM A182 / ASME SA 182 (SS 304, SS 316, Duplex, Super Duplex, High Nickel Alloys, Carbon Steel, Alloy Steel, etc.)
Manufacturing: Forged, Screwed, Threaded, Plate-cut
- Stainless Steels: 304/L/H/N, 316/L/H/N/Ti, 321/H, 310S, 347/H, 317L, 904L
- Duplex & Super Duplex: UNS S31803, S32205, S32750, S32760, F51, F53, F55
- High Alloys: Inconel, Monel, Hastelloy, Nickel Alloys, 17-4PH, 254SMO
- Carbon & Alloy Steels: ASTM/ASME A105, A350 LF2, A694, F11, F22, F91
Dimensional Range & Pressure Classes
- Sizes: ½” (15NB) to 48” (1200NB)
- Class Ratings: 150#–2500#
- DIN: PN6–PN160
- JIS: 5K–63K
- Dimensions: DN15–DN1500 (150–600#), DN15–DN1000 (900#), DN15–DN600 (1500#), DN15–DN300 (2500#)
International Standards
- ASME / ANSI: B16.5, B16.36, B16.47A/B, B16.48, B16.34
- DIN / EN / ISO: DIN, EN-1092, ISO 7005-1, PN, GOST
- BS / JIS / API: BS 4504, BS 10, BS 1560-3.1, JIS B2220, API 605
- Other: IS, SAE, CSN, UNI, EU
Surface Treatments
- Sand Blasting / Sand Rolling
- Oil Black Paint or Transparent Yellow
- Cold & Hot Dip Galvanized
- Anti-Rust Coatings
- Zinc-Plated & Custom Finishes
Supply & Logistics
- Origin: India, Japan, Korea, USA, Europe, Russia, Ukraine (No China)
- Ports: Mumbai & Nhava Sheva / Kalamboli
- Delivery: 7–15 working days
- Payment: T/T, L/C, PayPal, Western Union, Trade Assurance
- Samples: Free sample for ready stock
Testing & Quality Assurance
- Raw Material Certificates (EN 10204/3.1B)
- Mechanical & Chemical Verification
- Radiography (100%) & X-Ray
- Ferrite, Hardness & Impact Tests
- Intergranular Corrosion Testing
- PMI, PT, UT, HIC, SSC & Metallurgical Analysis
- Third Party Inspection (TPI)
Applications & Industries
- Oil & Gas Refineries
- Petrochemical & Chemical Plants
- Power & Nuclear Industries
- Water Treatment & Desalination
- Marine & Shipbuilding
- Pharmaceutical & Food Processing
- Metallurgy, Gas, and Engineering
Face Types
RF, FF, RTJ, LJF, M&F, T&G
Manufacturing
Forged, Screwed, Threaded, Plate-cut
Lead Time
7–15 working days, depends on quantity
Reports
TPI, Radiography, EN 10204/3.1B
Applications Across Industries
- Oil & Gas: High-pressure pipelines, refineries, and offshore platforms.
- Chemical & Petrochemical: Corrosion-resistant connections for aggressive chemicals.
- Power Plants: Boilers, turbines, and high-temperature pipelines.
- Marine & Shipbuilding: Sea water systems and desalination plants.
- Water & Wastewater: Pipelines for potable water and treatment systems.
- Food & Pharmaceuticals: Hygienic connections for fluids and processing lines.
- Metallurgy & Heavy Industry: Steam, hot water, and process fluid pipelines.
ASME B16.5 Stainless Steel Slip-On Flanges – Dimensions
| Class | Pipe Size (DN / Inch) | Outside Dia (A, mm) | Bolt Circle (D, mm) | No. of Bolts (L) | Bolt Dia (mm) | Flange Thickness (B, mm) | Hub Dia (G, mm) | Inside Dia (K, mm) | Raised Face Height (H, mm) | Stud Bolt (Dia x Length) |
|---|---|---|---|---|---|---|---|---|---|---|
| 150 | ½” / 15 | 30 | 90 | 4 | 15.9 | 9.6 / 11.2 | 35.1 | 60.3 | 14 / 15.6 | ½” x 55 |
| 300 | ½” / 15 | 38 | 95 | 4 | 15.9 | 12.7 / 14.3 | 35.1 | 66.7 | 21 / 22.6 | ½” x 65 |
| 600 | ½” / 15 | 38 | 95 | 4 | 15.9 | 14.3 / 20.7 | 35.1 | 66.7 | 22 / 28.4 | ½” x 75 |
| 900 | ¾” / 20 | 38 | 120 | 4 | 22.2 | 22.3 / 28.7 | 35.1 | 82.6 | 32 / 38.4 | ¾” x 110 |
| 1500 | ¾” / 20 | 38 | 120 | 4 | 22.2 | 22.3 / 28.7 | 35.1 | 82.6 | 32 / 38.4 | ¾” x 110 |
| 2500 | … | … | … | … | … | … | … | … | … | … |
Notes:
- Top row values exclude raised face height; bottom row values include raised face height.
- Slip-On Flanges are welded inside and outside for durability and leak-proof performance.
- Dimensions follow ASME B16.5 standards, ensuring global compatibility.
- Suitable for oil & gas, chemical, power, marine, and water treatment industries.
- Table can be extended for larger sizes and higher pressure classes as needed.
Flange Material Grades
Austenitic Stainless Steel
- 304 / 304L / 304H / 304N
- 316 / 316L / 316H / 316N / 316Ti
- 321 / 321H, 309 / 309H, 310S
- 317 / 317L / 904L
- Standards: ASTM/ASME A182 F304, F304L, F304H, F316, F316L, F321, F321H, F347H
Super Stainless Steel
- F44, F904L, F317L
- High-performance stainless alloys for extreme corrosion resistance
Duplex & Super Duplex Steels
- UNS S31803, S32205, S32750, S32760
- ASTM A182 F51, F53, F55
- Ideal for high strength and stress corrosion environments
Nickel-Based Alloys
- Nickel Alloy: N4 / UNS N02201, N6 / UNS N02200
- Inconel: N06600, N06601, N06617, N06625, N07718, N07750, N08800, N08810, N08811, N08825, N09925, N08926
- Hastelloy & Monel: High corrosion resistance for extreme environments
Precipitation-Hardening Steels
- 254SMO / S31254
- 17-4PH, 17-7PH, 15-7PH
- High-strength steels with excellent corrosion resistance
Alloy Steels
- ASTM/ASME A182 F11, F12, F22, F5, F9, F91
- Suitable for high-temperature and pressure applications
Carbon Steels
- ASTM/ASME A105, A350 LF2, A694 / A694M, F42, F52, F56, F60, F65, F70
- Widely used for general industrial piping applications
Applications
- Used in petrochemical, marine, power, and chemical industries
- Ensures corrosion resistance, strength, and durability
Stainless Steel Flange Standards & Types
Overview
Our stainless steel flanges comply with international standards and are available in multiple types, sizes, and pressure ratings to suit a wide range of industrial applications. The standards ensure compatibility, safety, and reliability for high-pressure and corrosive environments.
ASME / ANSI Standards
- B16.5: Welding Neck, Slip-On, Socket Weld, Lap Joint, Threaded, RTJ, Blind, High Hub Blind – ½” – 48” (Class 300–2500)
- B16.36: Welding Neck, Slip-On (SORF), Threaded – ½” – 48” (Class 300–2500)
- B16.47 Series A & B: Welding Neck, Blind – 2” – 60” (Class 75–900, PN2.5–PN40)
British Standards
- BS 4504: Welding Neck, Hubbed Slip-On, Lapped Pipe End, Plate, Loose Plate, Hubbed Threaded, Blank – DN15–DN1200 (Class 150–2500)
- BS 10: Welding Neck, Slip-On Boss, Plate Slip-On, Screwed Boss, Blind – DN15–DN1000 (Tables D–H)
- BS 1560 (Boss Type): Welding Neck, Slip-On, Blind, Socket Weld, Screwed Boss, Lapped Flanges – DN15–DN1200 (PN6–PN100)
DIN / European
- Welding Neck, Slip-On, Blind, Threaded, Plate
- DN10 – DN4000
- PN2.5 – PN400
JIS / Japanese
- Welding Neck, Slip-On, Blind, Threaded
- DN10 – DN1200
- 5K – 63K
EN 1092-1 / European
- Plate, Blank, Loose Plate, Hubbed Slip-On, Welding Neck, Hubbed Threaded
- DN10 – DN4000
- PN6 – PN400
ISO / International
- Welding Neck, Slip-On, Blind, Threaded, RTJ
- DN10 – DN4000
- PN2.5 – PN400 / Class 75–2500
China / GB Standards
- Blind, Lap Joint, Plate, Welding Neck, Slip-On, Threaded, Long Welding Neck
- DN10 – DN1200
- 0.25 – 10 MPa
EN 1092-2 Stainless Steel Flange Weight Chart (kg)
This chart provides approximate weights for stainless steel flanges based on nominal pipe size and pressure class, covering all common flange types: Slip-On, Threaded, Socket Weld, Lap Joint, Blind, and Weld Neck Flanges.
| Pressure Class | Nominal Pipe Size | Slip-On | Threaded | Socket Weld | Lap Joint | Blind | Weld Neck |
|---|---|---|---|---|---|---|---|
| 150 | ½” | 1 | 1 | 2 | 1 | 2 | 2 |
| 150 | ¾” | 2 | 2 | 2 | 2 | 2 | 2 |
| 150 | 1” | 2 | 2 | 2 | 2 | 2 | 3 |
| 150 | 1¼” | 3 | 3 | 3 | 3 | 3 | 3 |
| 150 | 1½” | 3 | 3 | 3 | 3 | 4 | 4 |
| 150 | 2” | 5 | 5 | 5 | 5 | 5 | 6 |
| 150 | 2½” | 8 | 8 | 8 | 8 | 7 | 10 |
| 150 | 3” | 9 | 9 | 9 | 9 | 9 | 11.5 |
| 150 | 3½” | 11 | 12 | 11 | 11 | 13 | 12 |
| 150 | 4” | 13 | 13 | 13 | 13 | 17 | 16.5 |
| 150 | 5” | 15 | 15 | 15 | 15 | 20 | 21 |
| 150 | 6” | 19 | 19 | 19 | 19 | 27 | 26 |
| 150 | 8” | 30 | 30 | 30 | 30 | 47 | 42 |
| 150 | 10” | 43 | 43 | 43 | 43 | 70 | 54 |
| 150 | 12” | 64 | 64 | 64 | 64 | 123 | 88 |
| 150 | 14” | 90 | 90 | 90 | 105 | 140 | 114 |
| 150 | 16” | 106 | 98 | 98 | 140 | 180 | 140 |
| 150 | 18” | 130 | 130 | 130 | 160 | 220 | 165 |
| 150 | 20” | 165 | 165 | 165 | 195 | 285 | 197 |
| 150 | 22” | 185 | 185 | 185 | 245 | 355 | 225 |
| 150 | 24” | 220 | 220 | 220 | 275 | 430 | 268 |
| 300 | ½” | 2 | 2 | 3 | 2 | 2 | 2 |
| 300 | ¾” | 3 | 3 | 3 | 3 | 3 | 3 |
| 300 | 1” | 3 | 3 | 3 | 3 | 4 | 4 |
| 300 | 1¼” | 4.5 | 4.5 | 4 | 4.5 | 6 | 5 |
| 300 | 1½” | 6.5 | 6.5 | 6 | 6.5 | 7 | 7 |
| 300 | 2” | 7 | 7 | 7 | 7 | 8 | 9 |
| 300 | 2½” | 10 | 10 | 10 | 10 | 12 | 12 |
| 300 | 3” | 13 | 14 | 13 | 14.5 | 16 | 18 |
| 300 | 3½” | 17 | 17 | 17 | 17 | 21 | 20 |
| 300 | 4” | 23.5 | 24 | 22 | 24 | 28 | 26.5 |
| 300 | 5” | 29 | 31 | 28 | 28 | 37 | 36 |
| 300 | 6” | 39 | 39 | 39 | 39 | 50 | 45 |
| 300 | 8” | 58 | 58 | 58 | 58 | 81 | 69 |
| 300 | 10” | 81 | 81 | 81 | 91 | 124 | 100 |
| 300 | 12” | 115 | 115 | 115 | 140 | 185 | 142 |
| 300 | 14” | 165 | 165 | 165 | 190 | 250 | 206 |
| 300 | 16” | 210 | 220 | 190 | 234 | 315 | 250 |
| 300 | 18” | 253 | 280 | 250 | 305 | 414 | 320 |
| 300 | 20” | 315 | 325 | 315 | 375 | 515 | 400 |
| 300 | 22” | 370 | 370 | 370 | 435 | 640 | 465 |
| 300 | 24” | 490 | 490 | 475 | 550 | 800 | 580 |
Notes: Slip-On, Threaded, Socket Weld, Lap Joint, Blind, and Weld Neck flange weights are approximate and follow EN 1092-2 standards. Actual weight may vary slightly depending on manufacturer and material grade.
EN 1092-2 Stainless Steel Flange Weight Chart (400 lb and above)
| Pressure Class | Nominal Pipe Size | Slip-On | Threaded | Socket Weld | Lap Joint | Blind | Weld Neck |
|---|---|---|---|---|---|---|---|
| 400 | ½” | 2 | 2 | 2 | 2 | 2 | 3 |
| 400 | ¾” | 3 | 3 | 3 | 3 | 3 | 3.5 |
| 400 | 1” | 3.5 | 3.5 | 3.5 | 3.5 | 4 | 4 |
| 400 | 1¼” | 4.5 | 4.5 | 4.5 | 4.5 | 6 | 4.5 |
| 400 | 1½” | 6.5 | 6.5 | 6.5 | 6.5 | 8 | 8 |
| 400 | 2” | 8 | 8 | 8 | 8 | 10 | 10 |
| 400 | 2½” | 12 | 12 | 12 | 11 | 15 | 14 |
| 400 | 3” | 15 | 15 | 15 | 14 | 20 | 18 |
| 400 | 3½” | 21 | 21 | 21 | 20 | 29 | 26 |
| 400 | 4” | 26 | 26 | 26 | 25 | 33 | 35 |
| 400 | 5” | 31 | 31 | 31 | 29 | 44 | 43 |
| 400 | 6” | 44 | 44 | 44 | 42 | 61 | 57 |
| 400 | 8” | 67 | 67 | 67 | 64 | 100 | 89 |
| 400 | 10” | 91 | 91 | 91 | 110 | 155 | 125 |
| 400 | 12” | 130 | 130 | 130 | 152 | 226 | 175 |
| 400 | 14” | 191 | 191 | 191 | 210 | 310 | 233 |
| 400 | 16” | 253 | 253 | 253 | 280 | 398 | 295 |
| 400 | 18” | 310 | 310 | 310 | 345 | 502 | 360 |
| 400 | 20” | 378 | 378 | 378 | 420 | 621 | 445 |
| 400 | 22” | 405 | 405 | 405 | 455 | 720 | 505 |
| 400 | 24” | 539 | 539 | 539 | 615 | 936 | 640 |
| 600 | ½” | 2 | 2 | 2 | 2 | 3 | 3 |
| 600 | ¾” | 3 | 3 | 3 | 3 | 4 | 4 |
| 600 | 1” | 4 | 4 | 4 | 4 | 4 | 4 |
| 600 | 1¼” | 5 | 5 | 5 | 5 | 6 | 6 |
| 600 | 1½” | 7 | 7 | 7 | 7 | 8 | 8 |
| 600 | 2” | 9 | 9 | 9 | 9 | 10 | 12 |
| 600 | 2½” | 13 | 13 | 13 | 12 | 15 | 18 |
| 600 | 3” | 16 | 16 | 16 | 15 | 20 | 23 |
| 600 | 3½” | 21 | 21 | 21 | 20 | 29 | 26 |
| Pressure Class | Nominal Pipe Size | Slip-On | Threaded | Socket Weld | Lap Joint | Blind | Weld Neck |
|---|---|---|---|---|---|---|---|
| 900 | ½” | 6 | 6 | 6 | 6 | 4 | 7 |
| 900 | ¾” | 6 | 6 | 6 | 6 | 6 | 7 |
| 900 | 1” | 7.5 | 7.5 | 7.5 | 7.5 | 9 | 8.5 |
| 900 | 1¼” | 10 | 10 | 10 | 10 | 10 | 10 |
| 900 | 1½” | 14 | 14 | 14 | 14 | 14 | 14 |
| 900 | 2” | 22 | 22 | 22 | 21 | 25 | 24 |
| 900 | 2½” | 31 | 31 | 31 | 25 | 32 | 31 |
| 900 | 3” | 36 | 36 | 36 | 29 | 35 | 36 |
| 900 | 4” | 53 | 53 | 53 | 51 | 54 | 53 |
| 900 | 5” | 83 | 83 | 83 | 81 | 87 | 86 |
| 900 | 6” | 110 | 110 | 110 | 105 | 115 | 110 |
| 900 | 8” | 172 | 172 | 172 | 190 | 200 | 187 |
| 900 | 10” | 245 | 245 | 245 | 277 | 290 | 268 |
| 900 | 12” | 326 | 326 | 326 | 371 | 415 | 372 |
| 900 | 14” | 400 | 400 | 400 | 415 | 520 | 562 |
| 900 | 16” | 459 | 459 | 459 | 488 | 619 | 685 |
| 900 | 18” | 647 | 647 | 647 | 670 | 880 | 924 |
| 900 | 20” | 792 | 792 | 792 | 868 | 1107 | 1164 |
| 900 | 24” | 1480 | 1480 | 1480 | 1659 | 2099 | 2107 |
| 1500 | ½” | 6 | 6 | 6 | 6 | 4 | 7 |
| 1500 | ¾” | 6 | 6 | 6 | 6 | 6 | 7 |
| 1500 | 1” | 8 | 8 | 8 | 8 | 9 | 9 |
| 1500 | 1¼” | 10 | 10 | 10 | 10 | 10 | 10 |
| 1500 | 1½” | 14 | 14 | 14 | 14 | 14 | 14 |
| 1500 | 2” | 25 | 25 | 25 | 25 | 25 | 25 |
| 1500 | 2½” | 36 | 36 | 36 | 35 | 35 | 36 |
| 1500 | 3” | 48 | 48 | 48 | 47 | 48 | 48 |
| 1500 | 4” | 73 | 73 | 73 | 75 | 73 | 73 |
| 1500 | 5” | 132 | 132 | 132 | 140 | 140 | 132 |
| 1500 | 6” | 165 | 165 | 165 | 170 | 160 | 165 |
| 1500 | 8” | 260 | 260 | 260 | 286 | 302 | 275 |
| 1500 | 10” | 436 | 436 | 436 | 485 | 510 | 455 |
| 1500 | 12” | 667 | 667 | 667 | 749 | 775 | 690 |
| 1500 | 14” | 940 | 940 | 940 | 890 | 975 | 940 |
| 1500 | 16” | 1250 | 1250 | 1250 | 1250 | 1300 | 1250 |
| 1500 | 18” | 1625 | 1625 | 1625 | 1475 | 1750 | 1625 |
| 1500 | 20” | 2050 | 2050 | 2050 | 1775 | 2225 | 2050 |
| 1500 | 24” | 2825 | 2825 | 2825 | 2825 | 3625 | 3325 |
| 2500 | ½” | – | 7 | – | 7 | 7 | 8 |
| 2500 | ¾” | – | 9 | – | 8 | 10 | 9 |
| 2500 | 1” | – | 12 | – | 12 | 12 | 13 |
| 2500 | 1¼” | – | 18 | – | 17 | 18 | 20 |
| 2500 | 1½” | – | 25 | – | 24 | 25 | 28 |
| 2500 | 2” | – | 38 | – | 37 | 39 | 42 |
| 2500 | 2½” | – | 55 | – | 53 | 56 | 52 |
| 2500 | 3” | – | 83 | – | 80 | 86 | 94 |
| 2500 | 4” | – | 127 | – | 122 | 133 | 146 |
| 2500 | 5” | – | 210 | – | 204 | 223 | 244 |
| 2500 | 6” | – | 323 | – | 314 | 345 | 378 |
| 2500 | 8” | – | 485 | – | 471 | 533 | 576 |
| 2500 | 10” | – | 925 | – | 897 | 1025 | 1068 |
| 2500 | 12” | – | 1300 | – | 1262 | 1464 | 1608 |
EN 1092-1 Stainless Steel Forged Flanges – Chemical Composition
| SS Grade | C (max/min) | Mn (max) | Si (max) | P (max) | S (max) | Cr (min/max) | Mo (max) | Ni (min/max) | N (max) |
|---|---|---|---|---|---|---|---|---|---|
| 304 | 0.08 max | 2.0 max | 0.75 max | 0.045 max | 0.030 max | 18.0–20.0 | 0.0 | 8.0–10.5 | 0.10 max |
| 304L | 0.03 max | 2.0 max | 0.75 max | 0.045 max | 0.030 max | 18.0–20.0 | 0.0 | 8.0–12.0 | 0.10 max |
| 304H | 0.04 min – 0.10 max | 2.0 max | 0.75 max | 0.045 max | 0.030 max | 18.0–20.0 | 0.0 | 8.0–10.5 | 0.10 max |
| 304N | 0.08 max | 2.0 max | 0.75 max | 0.045 max | 0.030 max | 18.0–20.0 | 0.0 | 8.0–10.5 | 0.10–0.16 |
| 316 | 0.08 max | 2.0 max | 0.75 max | 0.045 max | 0.030 max | 16.0–18.0 | 2.0–3.0 | 10.0–14.0 | 0.10 max |
| 316L | 0.03 max | 2.0 max | 0.75 max | 0.045 max | 0.030 max | 16.0–18.0 | 2.0–3.0 | 10.0–14.0 | 0.10 max |
| 316H | 0.04 min – 0.10 max | 2.0 max | 0.75 max | 0.045 max | 0.030 max | 16.0–18.0 | 2.0–3.0 | 10.0–14.0 | 0.10 max |
| 316N | 0.08 max | 2.0 max | 0.75 max | 0.045 max | 0.030 max | 16.0–18.0 | 2.0–3.0 | 10.0–14.0 | 0.10–0.16 |
| 316Ti | 0.08 max | 2.0 max | 0.75 max | 0.045 max | 0.030 max | 16.0–18.0 | 2.0–3.0 | 10.0–14.0 | 0.07–0.12 |
| 321 | 0.08 max | 2.0 max | 0.75 max | 0.045 max | 0.030 max | 17.0–19.0 | 0.0 | 9.0–12.0 | 0.10 max |
| 321H | 0.04 min – 0.10 max | 2.0 max | 0.75 max | 0.045 max | 0.030 max | 17.0–19.0 | 0.0 | 9.0–12.0 | 0.10 max |
| 309 | 0.08 max | 2.0 max | 0.75 max | 0.045 max | 0.030 max | 22.0–24.0 | 0.0 | 12.0–15.0 | 0.10 max |
| 309H | 0.04 min – 0.10 max | 2.0 max | 0.75 max | 0.045 max | 0.030 max | 22.0–24.0 | 0.0 | 12.0–15.0 | 0.10 max |
| 310S | 0.08 max | 2.0 max | 0.75 max | 0.045 max | 0.030 max | 24.0–26.0 | 0.0 | 19.0–22.0 | 0.10 max |
| 317 | 0.08 max | 2.0 max | 0.75 max | 0.045 max | 0.030 max | 18.0–20.0 | 3.0 | 11.0–14.0 | 0.10 max |
| 317L | 0.03 max | 2.0 max | 0.75 max | 0.045 max | 0.030 max | 18.0–20.0 | 3.0 | 11.0–14.0 | 0.10 max |
| 904L | 0.02 max | 2.0 max | 0.75 max | 0.045 max | 0.035 max | 19.0–23.0 | 4.0–5.0 | 24.0–26.0 | 0.10 max |
A182 Stainless Steel Flanges – Mechanical Properties
| SS Grade | Tensile Strength (MPa) min | Yield Strength 0.2% Proof (MPa) min | Elongation (% in 50mm) min | Hardness Brinell (HB) max | Hardness Rockwell B (HR B) max |
|---|---|---|---|---|---|
| 304 | 515 | 205 | 40 | 201 | 92 |
| 304H | 515 | 205 | 40 | 201 | 92 |
| 304L | 485 | 170 | 40 | 201 | 92 |
These mechanical properties define the minimum strength, elongation, and hardness of A182 stainless steel flanges, ensuring their durability in high-pressure, high-temperature, and corrosive environments. They are suitable for critical applications in chemical processing, power plants, oil & gas, and petrochemical industries. The elongation and hardness values indicate excellent toughness and resistance to deformation during installation and operation.
ANSI B16.5 Stainless Steel Flanges – Equivalent Grades
| SS Grade | UNS Number | Japanese JIS | Euronorm | Old British Standard |
|---|---|---|---|---|
| 304L | S30403 | SUS 304L | 1.4306 | 304S11 |
| 304 | S30400 | SUS 304 | 1.4301 | 304S31 |
| 304H | S30409 | - | 1.4948 | 304S51 |
This table provides approximate equivalents of common stainless steel flange grades according to different international standards. These comparisons help engineers and procurement teams identify functionally similar materials when working across global specifications. Always verify original standards for precise engineering and contractual requirements, as slight variations in composition or mechanical properties can affect flange performance in critical systems.
FAQs on Stainless Steel Flanges
1. What are stainless steel flanges used for?
Stainless steel flanges are used to connect pipes, valves, pumps, and other equipment in piping systems. They provide easy assembly and disassembly, ensuring leak-free connections in industries like oil & gas, chemical, petrochemical, power plants, shipbuilding, and water treatment.
2. What grades of stainless steel are commonly used for flanges?
Common grades include 304, 304L, 304H, 316, 316L, 321, 317L, and high-performance grades like Duplex, Super Duplex, Inconel, Hastelloy, and Monel. Selection depends on corrosion resistance, mechanical strength, and operating environment.
3. What are the main types of stainless steel flanges?
Key types include:
- Weld Neck Flange – ideal for high-pressure applications.
- Slip-On Flange – easy to install and economical.
- Socket Weld Flange – used for small-diameter pipes.
- Threaded Flange – no welding required.
- Lap Joint Flange – used with stub ends.
- Blind Flange – seals the end of a pipe.
- Weld Neck Flange – ideal for high-pressure applications.
- Slip-On Flange – easy to install and economical.
- Socket Weld Flange – used for small-diameter pipes.
- Threaded Flange – no welding required.
- Lap Joint Flange – used with stub ends.
- Blind Flange – seals the end of a pipe.
4. What are the international standards for stainless steel flanges?
Common standards include:
- ASME/ANSI B16.5 & B16.47 – US standards for flange dimensions and pressure ratings.
- EN 1092-1 & EN 1092-2 – European standards.
- DIN, ISO, JIS, BS – German, international, Japanese, and British standards.
- ASME/ANSI B16.5 & B16.47 – US standards for flange dimensions and pressure ratings.
- EN 1092-1 & EN 1092-2 – European standards.
- DIN, ISO, JIS, BS – German, international, Japanese, and British standards.
5. What is the pressure rating of stainless steel flanges?
Pressure classes vary by standard:
- ASME/ANSI: 150, 300, 600, 900, 1500, 2500 lb
- DIN/EN: PN 2.5 to PN 400
- BS: 150, 300, 400, 600, 900, 1500, 2500 lb
The pressure rating is determined by flange type, size, and material.
- ASME/ANSI: 150, 300, 600, 900, 1500, 2500 lb
- DIN/EN: PN 2.5 to PN 400
- BS: 150, 300, 400, 600, 900, 1500, 2500 lb
The pressure rating is determined by flange type, size, and material.
6. How is a stainless steel flange selected for an application?
Selection is based on:
- Pipe size and pressure rating
- Material grade (corrosion resistance and temperature limits)
- Flange type (weld neck, slip-on, blind, etc.)
- Applicable standards and certifications (ASME, EN, ISO, etc.)
- Pipe size and pressure rating
- Material grade (corrosion resistance and temperature limits)
- Flange type (weld neck, slip-on, blind, etc.)
- Applicable standards and certifications (ASME, EN, ISO, etc.)
7. What is the difference between 304, 304L, and 304H stainless steel flanges?
304 – standard austenitic grade.
304L – low carbon version, reduces risk of intergranular corrosion during welding.
304H – high carbon version, suitable for high-temperature applications. Mechanical properties and tensile strength vary slightly, as detailed in ASTM A182.
304L – low carbon version, reduces risk of intergranular corrosion during welding.
304H – high carbon version, suitable for high-temperature applications. Mechanical properties and tensile strength vary slightly, as detailed in ASTM A182.
8. What testing is done on stainless steel flanges?
Typical tests include:
- Chemical composition verification
- Mechanical tests – tensile, yield, elongation, and hardness
- Non-destructive tests (NDT) – radiography (RT), ultrasonic (UT), dye penetrant (PT)
- Third-party inspection for critical applications
- Chemical composition verification
- Mechanical tests – tensile, yield, elongation, and hardness
- Non-destructive tests (NDT) – radiography (RT), ultrasonic (UT), dye penetrant (PT)
- Third-party inspection for critical applications
9. How are stainless steel flanges protected during transport?
Flanges are typically coated or packed to prevent corrosion. Methods include:
- Oil coating
- Anti-rust paint
- Zinc plating or galvanizing
- Packaging with protective wrapping for safe delivery
- Oil coating
- Anti-rust paint
- Zinc plating or galvanizing
- Packaging with protective wrapping for safe delivery
10. Can stainless steel flanges be used in extreme environments?
Yes, high-grade stainless steel flanges (e.g., Duplex, Super Duplex, Inconel, Hastelloy) are designed for corrosive, high-pressure, and high-temperature environments such as offshore oil rigs, chemical plants, and power generation systems. Proper grade selection ensures long-term durability.