Stainless Steel Pipe Flanges Overview
Amardeep Steel supplies ASTM A182 stainless steel flanges in all major grades F304, F304L, F316, F316L, F317L, F321, F347, F904L from ½" to 48" NB, Class 150# to 2500#. ISO 9001:2015 certified with EIL approval for PSU projects. Ready inventory: weld neck, slip-on, blind, socket weld flanges. Delivery to 60+ countries with full Mill Test Certificates (EN 10204 3.1/3.2). Stock pricing for bulk orders, request quote for project-specific requirements.
As recognised stainless steel flange suppliers in India, Amardeep Steel maintains ready inventory of all major grades F304, F304L, F304H, F316, F316L, F316H, F317L, F321, F321H, F347, F347H, F310, F310S, F446, and F904L in sizes from ½ inch NB to 48 inch NB and pressure classes from 150# to 2500# (PN6 to PN64). Every flange ships with original Mill Test Certificates (3.1/3.2) and complete heat and lot traceability.
Whether you require high-pressure ASTM A182 weld neck flanges for refinery piping, low-carbon 316L flanges for welded systems, or 904L flanges for aggressive acid environments, Amardeep Steel delivers with competitive pricing, fast turnaround, and proven export capability to 60+ countries. Contact us today for a current stainless steel flange price list and technical consultation.
Table of Contents
- Stainless Steel Flanges Price List & Cost Factors
- Material of Construction - Stainless Steel Flanges
- Types of Stainless Steel Flanges
- Stainless Steel Flanges by Standard
- Stainless Steel Flanges by Grade
- Full Specification
- SS Flange Dimensions
- Chemical Composition
- Mechanical Properties
- Pressure Rating Chart
- Applications
- Why Choose Amardeep Steel
- Frequently Asked Questions
Certifications & Approvals
Amardeep Steel maintains the highest quality standards with internationally recognised certifications:
- ISO 9001:2015 Certified Quality Management System
- PED 2014/68/EU Certified for European Pressure Equipment
- EIL (Engineers India Limited) Approved for PSU/Refinery Projects
- IBR (Indian Boiler Regulations) Certified
- NABL-Accredited Testing Laboratory for in-house quality verification
- Approved Vendor: HPCL, BPCL, IOC, ONGC, major EPCs
Every flange shipment includes original Mill Test Certificates (EN 10204 3.1/3.2) with complete heat and lot traceability. We perform PMI testing, hydrostatic pressure testing, ultrasonic testing, and radiography as per ASME standards before dispatch.
Manufacturing Capabilities & Facilities
Amardeep Steel operates an integrated manufacturing facility for stainless steel flanges with comprehensive in-house capabilities:
Material Grade Price Impact
- SS 304/304L: Base reference price (most economical general-purpose grade)
- SS 316/316L: 15–20% premium over 304 (marine, chloride resistance)
- SS 317L: 25–30% premium over 304 (higher molybdenum for acids)
- SS 321/347: 10–15% premium over 304 (high-temperature stabilised)
- SS 904L: 80–100% premium over 304 (super austenitic for severe corrosion)
Size & Pressure Class
- Larger NPS and higher pressure classes increase weight exponentially
- Example: 6" 150# WN flange ≈ 9.8 kg; 6" 900# WN flange ≈ 28 kg
- Price scales with material weight plus machining complexity
Stock vs Custom Manufacturing
- Stock sizes (up to 12" NB in 150#/300#): Immediate availability at standard pricing
- Custom sizes/pressure classes: 10–15 working day lead time, quote-based pricing
- Bulk orders (100+ pieces same spec): Volume discount 8–12% available
Certification & Testing
- Standard MTC (EN 10204 3.1): Included in base price
- Third-party inspection (Lloyds, SGS, TUV): Additional charges apply
- EIL-approved material for PSU projects: Premium pricing for compliance documentation
Contact us for real-time pricing as stainless steel flange costs fluctuate with LME nickel, chromium, and molybdenum rates. Share your specification (grade, size, pressure class, quantity) to sales@amardeepsteel.com or call for a project-specific quotation within 24 hours.
Request a detailed stainless steel flange price list →
Stainless Steel Flanges Price List & Cost Factors
Stainless steel flange prices vary based on grade, size, pressure class, and order quantity. At Amardeep Steel, we provide transparent factory-direct pricing with no hidden charges.
- SS 304/304L: Base reference price (most economical general-purpose grade)
- SS 316/316L: 15-20% premium over 304 (marine, chloride resistance)
- SS 317L: 25-30% premium over 304 (higher molybdenum for acids)
- SS 321/347: 10-15% premium over 304 (high-temperature stabilised)
- SS 904L: 80-100% premium over 304 (super austenitic for severe corrosion)
- Larger NPS and higher pressure classes increase weight exponentially.
- Stock sizes up to 12" NB in 150#/300# are available immediately; custom sizes require 10-15 working days.
- Standard MTC (EN 10204 3.1) is included in base price; third-party inspection and EIL documentation may add charges.
Contact us for real-time pricing as stainless steel flange costs fluctuate with LME nickel, chromium, and molybdenum rates. Share your specification (grade, size, pressure class, quantity) to sales@amardeepsteel.com or call for a project-specific quotation within 24 hours.
Request a detailed stainless steel flange price list →
Material of Construction - Stainless Steel Flanges
| Material | Standard | Grades |
|---|---|---|
| Stainless Steel Flanges | ASTM A182 / A240 | F304, 304L, 304H, 316, 316Ti, 316H, 316L, 316LN, 309S, 309H, 310S, 310H, 317, 317L, 321, 321H, 347, 347H, 201, 202, 904L |
| Alloy Steel Flanges | ASTM A182 | F1, F5, F9, F11, F22, F91 |
| Carbon Steel Flanges | ASTM A105 | Gr. F42, 46, 52, 56, 60, 65, 70 |
Types of Stainless Steel Flanges by Amardeep Steel
Amardeep Steel supplies all standard and custom types of SS flanges and stainless steel pipe flanges to suit every piping configuration.
Weld Neck Flanges
The Weld Neck Flange features a long tapered hub that provides reinforcement, distributes stress along the pipe wall, and reduces leakage risk under cyclic loading. Preferred for offshore oil platforms, refinery piping above 600# rating, and steam headers.
Slip-On Flanges
The Slip-On Flange slides over the pipe and is fillet-welded on both faces. It is cost-effective and easy to install for low-to-medium pressure applications.
Blind Flanges
A Blind Flange is a solid disc used to close a pipeline end, nozzle, or vessel opening. Essential for commissioning, hydrostatic testing ports, and future connection points.
Socket Weld Flanges
The Socket Weld Flange accepts the pipe in a socket and is fillet-welded externally, producing a smooth bore for small-bore high-pressure piping.
Screwed / Threaded Flanges
Threaded flanges connect without welding, making them suitable for hazardous environments and low-pressure small-bore systems requiring frequent disassembly.
Lap Joint Flanges
Lap Joint Flanges are used with stub ends, allowing free rotation for easy bolt-hole alignment and frequent dismantling in food and beverage service.
Orifice Flanges
Orifice Flanges are matched pairs used with orifice plates for accurate flow measurement in oil, gas, petrochemical, and water utility metering.
Spectacle Blind Flanges
Spectacle Blind Flanges combine a blind and spacer ring for positive isolation or flow by rotating the unit 180 degrees during shutdown and maintenance.
Additional Flange Types
- Reducing Flanges — Connects two pipes of different nominal sizes in a single fitting.
- Ring Type Joint (RTJ) Flanges — Metal-to-metal seating for extreme pressure/temperature service.
- Groove & Tongue Flanges — Precision-machined mating faces for contained gasket sealing.
- Plate Flanges — Flat plate flanges, cost-effective for low-pressure / non-standard sizes.
- Flat Face Flanges — Full-face gasket contact, ideal for cast-iron mating equipment.
Stainless Steel Flanges by Standard
|
Standard |
Description |
|---|---|
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Most widely used standard up to 24" NPS |
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European pressure flange standard |
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German standard (PN6–PN100) |
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British Standard tables A–H |
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British Standard metric flanges |
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Japanese Industrial Standard |
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For Indian PSU/refinery projects |
Stainless Steel Flanges by Grade
We stock all popular ASTM A182 grades. Full specifications, chemical composition, and pricing available on request.
|
Grade |
UNS No. |
Key Characteristic |
|---|---|---|
|
S30400 |
General purpose, food grade |
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S30403 |
Low carbon, weld sensitisation |
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S30409 |
High-C, creep resistance |
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S31000 |
High temp up to 1150°C |
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S31008 |
Low-C 310, oxidation resist. |
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S31600 |
Marine & acid resistance |
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S31603 |
Low-C, welded applications |
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S31609 |
High-temp elevated service |
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S31700 |
Better corrosion vs 316 |
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S31703 |
Low-C 317, pitting resist. |
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S32100 |
Ti-stabilised, sensitisation |
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S32109 |
Hi-C, creep strength |
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S34700 |
Nb+Ta stabilised |
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S34709 |
Elevated temp service |
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S44600 |
Ferritic, high-temp oxidation |
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N08904 |
Super austenitic, strong acids |
Stainless Steel Flanges - Full Specification
| Parameter | Details |
|---|---|
| Material Standard | ASTM A182 / ASME SA182 |
| Dimensional Standards | ANSI/ASME B16.5, B16.47 Series A & B, B16.48, BS4504, BS 10, EN-1092, DIN, JIS |
| Size Range | 1/2" (15 NB) to 48" (1200 NB) - custom sizes on request |
| Pressure Classes | 150#, 300#, 400#, 600#, 900#, 1500#, 2500#; PN6, PN10, PN16, PN25, PN40, PN64 |
| Facing Types | Raised Face (RF), Flat Face (FF), Ring Type Joint (RTJ), Tongue & Groove (T&G), Male & Female |
| Grades Stocked | F304, 304L, 304H, 316, 316L, 316H, 317L, 310, 310S, 321, 321H, 347, 347H, 446, 904L, 201, 202 |
| Testing | PMI, Hydrostatic, Radiography, UT, MPT/DPT, Spectro Analysis, NACE MR-0175 |
| Certifications | ISO 9001:2015, PED 2014/68/EU, EIL, IBR, NABL-accredited lab |
| Origin | India (Mumbai) - exported to 60+ countries |
SS Flange Dimensions - ASME B16.5 Class 150 Raised Face
| NPS | DN | Flange OD (mm) | Thk (mm) | SOW (kg) | WN (kg) | Blind (kg) | BCD (mm) | Bolts |
|---|---|---|---|---|---|---|---|---|
| 1/2" | 15 | 88.9 | 11.2 | 0.4 | 0.5 | 0.4 | 60.3 | 4 |
| 3/4" | 20 | 98.6 | 12.7 | 0.6 | 0.7 | 0.6 | 69.8 | 4 |
| 1" | 25 | 108 | 14.2 | 0.8 | 1.0 | 0.9 | 79.4 | 4 |
| 1-1/2" | 40 | 127 | 17.5 | 1.3 | 1.5 | 1.5 | 98.4 | 4 |
| 2" | 50 | 152.4 | 19 | 2.1 | 2.6 | 2.4 | 120.6 | 4 |
| 3" | 80 | 190.5 | 23.9 | 3.9 | 4.9 | 4.9 | 152.4 | 4 |
| 4" | 100 | 228.6 | 23.9 | 5.3 | 6.8 | 6.8 | 190.5 | 8 |
| 6" | 150 | 279.4 | 25.4 | 7.5 | 9.8 | 9.8 | 241.3 | 8 |
| 8" | 200 | 342.9 | 28.4 | 12.1 | 17.6 | 17.6 | 298.4 | 8 |
| 10" | 250 | 406.4 | 30.2 | 26.2 | 36.5 | 36.5 | 361.9 | 12 |
| 12" | 300 | 482.6 | 31.8 | 38.4 | 48.4 | 48.4 | 431.8 | 12 |
| 16" | 400 | 596.9 | 36.6 | 56.9 | 70.8 | 70.8 | 539.7 | 16 |
| 20" | 500 | 698.5 | 47.8 | 85.0 | 99.3 | 99.3 | 635.0 | 20 |
| 24" | 600 | 812.8 | 47.8 | 115 | 139 | 139 | 749.3 | 20 |
Full dimensional charts for all pressure classes available - use our Flange Weight Calculator.
Stainless Steel Flanges - Chemical Composition (ASTM A182, %)
| Grade | C | Mn | P | S | Si | Cr | Ni | Mo / Other |
|---|---|---|---|---|---|---|---|---|
| 304 | 0.08 | 2.00 | 0.045 | 0.030 | 1.00 | 18-20 | 8-10.5 | - |
| 304L | 0.03 | 2.00 | 0.045 | 0.030 | 1.00 | 18-20 | 8-12.0 | - |
| 316 | 0.08 | 2.00 | 0.045 | 0.030 | 1.00 | 16-18 | 10-14 | Mo 2-3 |
| 316L | 0.03 | 2.00 | 0.045 | 0.030 | 1.00 | 16-18 | 10-14 | Mo 2-3 |
| 317L | 0.03 | 2.00 | 0.045 | 0.030 | 0.75 | 18-20 | 11-15 | Mo 3-4 |
| 310S | 0.08 | 2.00 | 0.045 | 0.030 | 1.50 | 24-26 | 19-22 | - |
| 321 | 0.08 | 2.00 | 0.040 | 0.030 | 1.00 | 17-19 | 9-12 | Ti >=5xC |
| 347 | 0.08 | 2.00 | 0.040 | 0.030 | 1.00 | 17-19 | 9-13 | Nb >=10xC |
| 904L | 0.02 | 2.00 | 0.045 | 0.035 | 1.00 | 19-23 | 23-28 | Mo 4-5, Cu 1-2 |
Stainless Steel Pipe Flanges - Mechanical Properties
| Grade | UNS | Tensile (ksi) | Yield (ksi) | Elongation | HB max | HRB max |
|---|---|---|---|---|---|---|
| 304 | S30400 | 75 | 30 | 40% | 183 | 88 |
| 304L | S30403 | 70 | 25 | 40% | 183 | 88 |
| 316 | S31600 | 75 | 30 | 40% | 217 | 95 |
| 316L | S31603 | 70 | 25 | 35% | 217 | 95 |
| 317L | S31703 | 75 | 30 | 35% | 217 | 95 |
| 310S | S31008 | 75 | 30 | 40% | 217 | 95 |
| 321 | S32100 | 75 | 30 | 40% | 183 | 88 |
| 347 | S34700 | 75 | 30 | 40% | 183 | 88 |
| 309S | S30908 | 75 | 30 | 40% | 217 | 95 |
ANSI/ASME B16.34 - Pressure Rating Chart (SS 304/316, psi)
| Temp °F | 150# | 300# | 400# | 600# | 900# | 1500# | 2500# |
|---|---|---|---|---|---|---|---|
| -20 to 100 | 275 | 720 | 960 | 1440 | 2160 | 3600 | 6000 |
| 200 | 230 | 600 | 800 | 1200 | 1800 | 3000 | 5000 |
| 300 | 205 | 540 | 720 | 1080 | 1620 | 2700 | 4500 |
| 400 | 190 | 495 | 660 | 995 | 1490 | 2485 | 4140 |
| 500 | 170 | 465 | 620 | 930 | 1395 | 2330 | 3880 |
| 600 | 140 | 435 | 580 | 875 | 1310 | 2185 | 3640 |
| 700 | 110 | 425 | 565 | 850 | 1275 | 2125 | 3540 |
| 800 | 80 | 405 | 540 | 805 | 1210 | 2015 | 3360 |
| 900 | 50 | 390 | 520 | 780 | 1165 | 1945 | 3240 |
| 1000 | 20 | 320 | 430 | 640 | 965 | 1605 | 2675 |
| 1100 | 20 | 255 | 345 | 515 | 770 | 1285 | 2145 |
Top Industries for Stainless Steel Flange Applications
Oil & Gas Industry – Extreme Service Flanges
Stainless steel flanges are mission-critical in upstream, midstream, and downstream oil & gas operations:
- Upstream (Exploration & Production): Offshore platforms experience saltwater spray, H2S exposure, chloride pitting. Recommended grades: SS 316L (sour service), Duplex 2205/2507 (high strength + corrosion). Subsea wellhead flanges: RTJ face type, Class 900–2500, -46°C to 120°C. Weld neck flanges mandatory for structural integrity under wave loading.
- Midstream (Transmission Pipelines): Long-distance natural gas pipelines require Class 300–600 flanges. SS 321 preferred for high-temperature sour gas service above 450°C. Spectacle blinds used for pipeline isolation during maintenance.
- Downstream (Refineries & Petrochemical): Catalytic cracker units: SS 347H flanges resist carbide precipitation at 600–850°C. Hydrotreating units: SS 317L for naphthenic acid corrosion resistance. Steam-out connections: Class 1500 weld neck flanges per ASME B31.3.
Amardeep Steel supplies EIL-approved stainless steel flanges for major Indian refineries including HPCL Vizag, BPCL Mumbai, and IOC Gujarat. All flanges meet NACE MR0175/ISO 15156 requirements for H2S service.
Chemical Processing
In chemical plants, SS flanges connect pipes and reactors handling acids, alkalis, and solvents. Grade 316 (with Mo) resists pitting and crevice corrosion. 904L and 317L are chosen for concentrated sulfuric and phosphoric acid service. Operating temperatures typically range from -20°C to 300°C with Class 150 to 900 flanges most common.
Food & Beverage Industry
SS 304 and 316L flanges are sanitary choices for dairy, brewery, beverage, and food processing piping. The smooth, non-porous surface prevents bacterial growth. 3-A and FDA-compliant electropolished finishes (Ra ≤ 0.8 μm) are available on request. Lap joint flanges are widely used to allow easy CIP/SIP disassembly.
Power Generation
321H and 347H flanges withstand creep at elevated temperatures in power plant boilers, heat exchangers, and steam headers operating at 550–750°C. 310S flanges are used in furnace and high-temperature combustion piping. Class 900 and 1500 weld neck flanges are standard for high-pressure steam lines.
Pharmaceutical & Biotechnology
Ultra-high purity 316L flanges with electropolished surfaces (Ra ≤ 0.4 μm) are specified for pharmaceutical reactors, bioreactors, CIP/SIP systems, and water-for-injection (WFI) distribution. All flanges meet ASME BPE and 3-A sanitary standards. Full documentation including material declaration and certificates of conformance provided.
Marine & Shipbuilding
316 and 317L stainless flanges resist seawater corrosion in ship piping, ballast systems, desalination plants, and offshore installations. Operating environments involve continuous seawater contact at up to 40°C. Copper-Nickel alloys (70/30, 90/10) are also available for severe marine service.
Why Choose Amardeep Steel as Your Stainless Steel Flange Supplier?
- 40+ Years Trusted Experience: Supplying HPCL, BPCL, IOC refineries since 1980s.
- Widest Grade Range: 304 to 904L, duplex, super duplex, alloy and carbon steel flanges under one roof.
- Mill-Direct Certification: Original MTCs (EN 10204 3.1/3.2) with every shipment.
- Custom Manufacturing: Non-standard sizes, special facings, and custom grades within 10-15 working days.
- Global Export Capability: Delivered to 60+ countries including UAE, Saudi Arabia, USA, UK, Germany, Singapore.
- Rigorous QA: PMI, hydrostatic, UT, radiography, MPT/DPT testing with NABL-accredited lab support.
- EIL & IBR Approved: Approved for major Indian PSU and refinery projects.
- Stock Availability: 5,000+ flanges in ready inventory covering 150#/300# in sizes 1/2" to 12" NB across 304/304L/316/316L grades.
Experience & Expertise
Since 1980, Amardeep Steel has supplied stainless steel flanges to over 2,500 industrial projects including HPCL Vizag refinery modernisation (2019), ONGC offshore platforms (2021–2023), and international LNG terminals in UAE and Singapore.
Our metallurgical team includes 5 ASME-certified welding inspectors, 3 NACE-certified corrosion specialists, and 12 quality engineers with an average 15 years experience in stainless steel manufacturing.
“Supplied 2,400 Class 600 316L weld neck flanges for our Gujarat refinery expansion. Zero rejections, on-time delivery, excellent technical support.” — Procurement Head, Major Indian PSU Refinery
Member: Indian Stainless Steel Development Association (ISSDA), All India Manufacturers Organisation (AIMO). 100% payment protection through secure banking channels. Export documentation assistance including fumigation certificates, material test certificates, and country-specific compliance paperwork.
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Contact us for integrated material supply packages with unified MTC documentation and consolidated shipping.
Frequently Asked Questions - Stainless Steel Flanges
What is an SS flange?
Stainless steel flanges (SS flanges) are essential piping components - circular forged discs with bolt holes around the rim - that connect pipes, valves, pumps, and equipment in a pipeline system. They create a pressure-tight, removable joint sealed with a gasket. They are made from corrosion-resistant stainless steel alloys per ASTM A182 / ASME SA182.
What is the standard for stainless steel flanges?
The primary dimensional standard is ASME B16.5 (covering flanges up to 24" NPS) and ASME B16.47 (for larger diameters). Material is governed by ASTM A182 / ASME SA182. Pressure-temperature ratings are per ASME B16.34. Other applicable standards include ASME B16.48, EN 1092-1, DIN 2631-2638, JIS B 2220, and BS 4504.
What is the ASME code for stainless steel flanges?
ASTM A182 (ASME SA182) covers forged or rolled alloy and stainless steel pipe flanges, fittings, and valves for high-temperature service. Common ASTM A182 flange grades include F304, F304L, F316, F316L, F317L, F321, F347, and F904L.
What size range is available?
Stainless steel flanges are available from 1/2 inch (15 NB) to 48 inch (1200 NB) as standard. Larger custom sizes and half-pipe flanges are manufactured on request.
What is the difference between 304 and 316 stainless steel flanges?
SS 304 flanges (UNS S30400) are the most widely used general-purpose grade with good corrosion resistance. SS 316 flanges (UNS S31600) contain 2-3% molybdenum, providing significantly better resistance to chlorides, marine atmospheres, and acidic environments. 316L is the low-carbon variant preferred when welding is involved to prevent intergranular corrosion.
Does Amardeep Steel supply EIL-approved flanges?
Yes. We supply EIL Approved Flanges with complete MECON, EIL, and IBR documentation for refinery and petrochemical projects in India. We are registered with major PSUs including HPCL, BPCL, IOC, and ONGC approved vendor lists.
What is the lead time for custom stainless steel flanges?
Standard custom flanges (non-stock sizes/pressure classes) require 10-15 working days from order confirmation. Complex specifications or large-diameter flanges above 30" NB may require 3-4 weeks. Stock flanges (150#/300# up to 12" NB) ship same-day or next-day. Rush orders available for critical shutdowns.
Can you supply stainless steel flanges for NACE MR0175 sour service?
Yes. We supply NACE MR0175/ISO 15156 compliant stainless steel flanges for H2S environments. Material certificates include SSC test results and HIC test reports. Common grades: 316L, 317L, Duplex 2205.
What is the minimum order quantity for stainless steel flanges?
No minimum order quantity for stock items. Custom manufacturing typically requires minimum 10 pieces per specification for economical production, but we accommodate smaller quantities on request.
Do you provide third-party inspection for flanges?
Yes, we facilitate third-party inspection by Lloyds Register, SGS, TUV, Bureau Veritas, or any buyer-specified agency. Inspection can be conducted at our facility or at the port before shipment.
Request a Quote for Stainless Steel Flanges
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