316/316L Stainless Steel Flanges

Corrosion Resistance: Excellent resistance to pitting and crevice corrosion in chloride-containing environments, seawater, and aggressive chemical media, thanks to 2–3% molybdenum content.

Weldability and Formability: The low carbon content of 316L prevents intergranular corrosion after welding; flanges are suitable for all standard welding processes.

Full Range of Types: Weld neck (WN), slip-on (SO), blind (BL), socket weld (SW), threaded (TH), lap joint (LJ), plate flanges, and orifice flanges.

Pressure Ratings: Available in Class 150, 300, 600, 900, 1500, and 2500 (PN6 to PN400 in metric equivalents).

Mechanical Strength: High tensile and yield strength combined with excellent ductility, suitable for high-pressure pipelines and critical bolted connections.

International Certifications: Flanges can be certified by ABS, BV, DNV, LR, GL, RINA, CCS, KR, and NK, and comply with NORSOK, PED, and ASME standards for global projects.

These standards ensure that our 316/316L stainless steel flanges meet global requirements for chemical composition, mechanical properties, dimensional tolerances, and pressure-temperature ratings.

The lower carbon content in 316L minimizes carbide precipitation during welding, providing enhanced resistance to intergranular corrosion compared to standard 316, especially in high-temperature or welded service environments.

Heat Treatment Condition:
All flanges are solution annealed at 1040–1080°C followed by rapid cooling (water quenching). This treatment restores full corrosion resistance, relieves internal stresses from forging, and enhances ductility, ensuring reliable performance in demanding chemical, marine, and offshore applications.

*Reference: ASME B16.5 – 316 stainless steel. De-rating factors apply for higher temperatures. For 316L the ratings are similar at lower temperatures.*

Standard Dimensions: ASME B16.5 for sizes up to 24″, and ASME B16.47 Series A/B for large diameters up to 60″. EN 1092-1 dimensions available upon request.

Raw Material Selection: High-quality 316/316L stainless steel bars or billets from certified mills (Baosteel, TISCO, POSCO, Outokumpu).

Cutting & Heating: Material is cut to precise weight and induction-heated to forging temperature.

Forging: Hot forged using hydraulic presses or hammer forging to shape the flange blank.

Heat Treatment: Solution annealing at 1040–1080°C followed by water quenching.

Machining: CNC lathes and milling machines produce precise dimensions, bolt holes, and facing surfaces (RF, RTJ, etc.).

Marking: Laser or stamping with grade, size, class, heat number, and standard (e.g., ASTM A182 F316L, ASME B16.5).

Inspection & Testing: Dimensional check, PMI, hardness, and NDT as required.

Surface Treatment: Pickling, passivation, or oil coating to prevent corrosion during storage/transport.

Each flange facing is inspected for surface roughness, concentricity, and absence of scratches or tool marks.

Chemical Analysis: PMI 100% verification using XRF spectrometer.

Mechanical Testing: Tensile, yield, elongation, hardness (per ASTM A370).

Dimensional Inspection: Bore diameter, OD, bolt circle, bolt hole alignment, hub thickness, flange face flatness.

NDT: Liquid Penetrant Testing (PT) for surface defects; Ultrasonic Testing (UT) for internal flaws upon request.

Hydrostatic / Pneumatic Testing: Applicable for special orders.

Intergranular Corrosion Test: ASTM A262 Practice E for 316L.

Third-Party Inspection: SGS, BV, DNV, TUV, or LR on customer request.

Chemical & Petrochemical: Acid transfer lines, reactor connections, heat exchanger flanges.

Marine & Offshore: Seawater cooling pipe flanges, ballast system connections, desalination plants (ABS/BV/DNV/LR certified).

Pharmaceutical & Food: Sanitary flanges with smooth finishes for clean service.

Power Generation: Condenser and boiler flanges, steam lines.

Water Treatment: Reverse osmosis, high-purity water distribution.

Oil & Gas: Wellhead flanges (API 6A), pipeline flanges for sour service (NACE MR0175 available).

Construction & Infrastructure: Structural flange connections for large-diameter piping.

Small flanges (≤4″): Packed in heavy-duty cartons with moisture barrier paper.

Medium & large flanges (≥6″): Wooden crates or pallets, each flange separated by foam padding.

Protection: Plastic end caps for bore; rust inhibitor oil applied to surfaces.

Labeling: Each flange individually tagged with grade, size, class, heat number, and standard.

Womic Steel’s Delivery Strengths:

Ready stock: Class 150 and 300 flanges in sizes 1/2″–24″ – dispatch within 24 hours.

Direct cooperation with global shipowners for competitive freight.

Professional loading by in-house teams ensures damage-free shipment.

Complete documentation for customs clearance (MTR, COO, packing list).

1. What is the difference between 316 and 316L flanges?
316L has lower carbon (≤0.03%), which prevents carbide precipitation during welding. For welded flange joints, 316L is preferred to avoid intergranular corrosion.

2. Can you supply flanges with custom bolt hole drilling?
Yes. We can accommodate non-standard bolt circle diameters, oversize bolt holes, or rotated bolt patterns upon request.

3. What is the maximum pressure rating for 316 flanges?
Class 2500 316 flanges have a rating of 6000 psig at 100°F. Higher pressure requires special design and materials.

4. Do you provide material test reports (MTR) and third-party inspection?
Yes. EN 10204 3.1 MTR included. Third-party inspection by SGS, BV, DNV, TUV available.

5. Are your flanges suitable for offshore/marine environments?
Absolutely. 316/316L offers excellent seawater corrosion resistance. We can supply ABS, DNV, LR approved flanges.

6. What facing is standard for raised face flanges?
Serrated concentric or spiral finish, 125–250 μinch roughness, as per ASME B16.5.

Complete Product Range: All flange types and pressure classes – one-stop sourcing.

Strict Quality Control: ISO 9001, PED 2014/68/EU, API Q1 certified.

Advanced Forging & Machining: Modern CNC equipment and heat treatment furnaces.

Full Traceability: Heat number stamped – traceable back to raw material.

Flexible Customization: Special sizes, facings, or non-standard materials available.

Global Delivery: Exported to over 50 countries.

Tel / WhatsApp:
Victor: +86 15575100681
Jack: +86 18390957568
E-mail: info@womicstainless.com
Website: www.womicsteel.com

Contact Womic Steel today for a competitive quote on 316/316L stainless steel flanges. We offer certified quality, fast production lead times, and reliable global delivery to keep your pipeline projects running smoothly.

Stock Examples (Class 150 WN RF – 316/316L):

1/2″ (DN15) × Sch40S

2″ (DN50) × Sch10S

4″ (DN100) × Sch40S

6″ (DN150) × Sch80S

12″ (DN300) × Sch40S

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