ASTM A350 LF2 Flanges
Midland Alloys Inc. is a trusted manufacturer and supplier of ASTM A350 LF2 flanges designed for low-temperature applications and demanding industrial settings. ASTM A350 LF2 is a type of carbon steel alloy designed for forged parts like flanges, fittings, and pressure piping that work in freezing to normal temperatures. These flanges are known for being top-notch tough, having high strength, low-temperature impact toughness, and weldability. Our range of weld neck, slip-on, socket weld, threaded, blind, and lap joint flanges are manufactured for rigorous industry standards. These flanges are ideal for oil and gas pipelines, offshore platforms, LNG terminals, and refrigeration systems where structural integrity in extremely cold temperatures is essential. Each product complies with applicable NACE requirements as well as ASTM A350 LF2, ASME B16.5, and ANSI B16.47.
ASTM A350 LF2 Flanges Overview
The ASTM A350 LF2 low-temperature carbon steel flange specification is utilized for forged parts such as flanges, valves and piping systems in subzero to normal temperature conditions. These flanges are well-known for their strong notch toughness and impact resistance, which guarantee dependable, and safe operation in extremely cold temperatures. The standard ASTM A350 LF2 chemical composition typically includes Carbon, Manganese and small amounts of Phosphorus, sulfur, and Silicon, enhancing its ductility and structural strength. These flanges are used by the engineers due to their superior toughness, ease of fabrication, and resistance to brittle fracture. Even under severe low-temperature conditions. They are produced in different forms, including weld neck, slip-on, socket weld, threaded, blind and lap joint flanges. Each piece adheres to industry benchmarks, including ASTM A350 LF2, ASME B16.5, ANSI B16.47 and MSS-SP-44. These flanges are essential to industries such as petrochemical plants, offshore rigs, cryogenic LNG terminals, and oil and gas infrastructure. In demanding cold environments, ASTM A350 LF2 flanges deliver consistent performance while meeting the most stringent technical standards.
Benefits of ASTM A350 LF2 Flanges
ASTM A350 LF2 flanges are specifically engineered for low-temperature and subzero service environments. They are known for their superior impact toughness, excellent mechanical properties, and dependable performance in cryogenic applications. These forged carbon steel flanges meet strict industry requirements for strength, weldability, and corrosion resistance.
- Reliable notch toughness performance at temperatures as low as -50°F (-46°C)
- Easy fabrication and good weldability utilizing common industrial processes
- Excellent durability and longevity for pipeline systems in cold climates
- Fits ASME/ANSI B16.5 and B16.47 fittings and flanges
- Superior resistance to brittle fracture in conditions below freezing
- Perfect for pipeline projects in cold climates, offshore rigs, and LNG processing
- Cost-effective option for applications using low-temperature carbon steel
- It conforms with the mechanical characteristics of ASTM A350 LF2 Classes 1 and 2.
ASTM A350 LF2 Flanges Standard Specification
Designed for use in low-temperature and subzero applications, ASTM A350 LF2 flanges conform to rigorous industry specifications for mechanical strength, chemical composition, and performance reliability.
1/2″NB TO 60″NB
A350 LF3/ A350 LF2
ANSI/ASME B16.5, B 16.47 Series A & B, B16.48, BS4504, BS 10, EN-1092, DIN, etc.
Threaded / Screwed / Forged / Plate
150#, 300#, 600#, 900#, 1500#, 2500#, PN6, PN10, PN16, PN25, PN40, PN64 etc.
Flate Face (FF), Raised Face (RF), Ring Type Joint (RTJ)
Forging, Rolling, Casting
FNPT, NPT, BSPT, MNPT, BSPP
Contact us today to discuss how ASTM A350 LF2 Flanges can benefit your application. Whether you need guidance in selecting the right pipes or have specific requirements, our team of experts is here to help you find the optimal solution.
Types of ASTM A350 LF2 Flanges
Midland Alloys Inc. provides a large selection of ASTM A350 LF2 flange types, such as weld neck, slip-on, socket weld, threaded, blind and lap joint flanges, to accommodate different piping applications.
Manufacturing Types
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SORF (Slip-On Raised Face)Slides over the pipe and gets welded for easy installation in low-pressure systems.
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BLRF (Blind Raised Face)Closes off pipe ends; used for testing or sealing flow in a system.
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SWRF (Socket Weld Raised Face)Pipe fits into a recessed area and is welded around the edge. Ideal for small-bore, high-pressure lines.
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WNRF (Weld Neck Raised Face)Has a long, tapered hub and welds to the pipe for strong, leak-proof joints under high pressure.
Face Forms
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Raised Face (RF)The most common type has a raised surface that improves gasket sealing in medium to high pressure.
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Ring Type Joint (RTJ)Uses a metal ring for sealing and works well in high-pressure, high-temperature services.
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Flat Face (FF)Flat surface flange used with cast iron or low-pressure piping where full face gasket is needed.
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Lap-Joint Face (LJF)Used with stub ends and are easy to align and install. Good for systems that need frequent dismantling.
Technical Details & Delivery Condition
ASTM A350 LF2 flanges consist of low-carbon steel, with equilibrated alloying constituents to provide enhanced strength and ductility in sub-zero temperatures. To improve its mechanical qualities, and resistance to brittle failure, the composition frequently contains carbon, manganese, and trace elements like silicon, phosphorus and sulfur.
| Element | Carbon | Manganese | Phosphorus | Sulfur | Silicon | Copper | Nickel | Chromium | Molybdenum | Vanadium |
|---|---|---|---|---|---|---|---|---|---|---|
| Composition, % | 0.35 max | 0.60 – 1.05 | 0.035 max | 0.040 max | 0.10 – 0.35 | 0.40 max (1) | 0.40 max (1) | 0.30 max (1-2) | 0.12 max (1-2) | 0.08 max |
| Properties | Imperial |
|---|---|
| Hardness, Bhn | Max 197 |
| EL (2″ Min) | 22% |
| RA Min | 30% |
| Set of 3 Specimen* | 15 (20) |
| YS Min psi (Mpa) | 36,000 (250) |
| TS Min psi (Mpa) | 70,000 (485) |
| For One Specimen | 12 (16) |
| NPS (inches) |
ASTM A350 Class 300 | ||||
|---|---|---|---|---|---|
| No. of Bolts |
Dia of Flange (inches) |
Bolt Circle (inches) |
Dia of Bolt Holes (inches) |
Dia of Bolts (inches) |
|
| 1/4 | 4 | 3-3/8 | 2-1/4 | 0.62 | 1/2 |
| 3/4 | 4 | 4-5/8 | 3-1/4 | 0.75 | 5/8 |
| 1 | 4 | 4-7/8 | 3-1/2 | 0.75 | 5/8 |
| 2-1/2 | 8 | 7-1/2 | 5-7/8 | 0.88 | 3/4 |
| 3 | 8 | 8-1/4 | 6-5/8 | 0.88 | 3/4 |
| 2 | 8 | 6-1/2 | 5 | 0.75 | 5/8 |
| 4 | 8 | 10 | 7-7/8 | 0.88 | 3/4 |
| 5 | 8 | 11 | 9-1/4 | 0.88 | 3/4 |
| 3-1/2 | 8 | 9 | 7-1/4 | 0.88 | 3/4 |
| 8 | 12 | 15 | 13 | 1 | 7/8 |
| 24 | 24 | 36 | 32 | 1.62 | 1-1/2 |
| 18 | 24 | 28 | 24-3/4 | 1.38 | 1-1/4 |
| 10 | 16 | 17-1/2 | 15-1/4 | 1.12 | 1 |
| 6 | 12 | 12-1/2 | 10-5/8 | 0.88 | 3/4 |
| 1/2 | 4 | 3-3/4 | 2-5/8 | 0.62 | 1/2 |
| 14 | 20 | 23 | 20-1/4 | 1.25 | 1-1/8 |
| 1-1/4 | 4 | 5-1/4 | 3-7/8 | 0.75 | 5/8 |
| 1-1/2 | 4 | 6-1/8 | 4-1/2 | 0.88 | 3/4 |
| 16 | 20 | 25-1/2 | 22-1/2 | 1.38 | 1-1/4 |
| 12 | 16 | 20-1/2 | 17-3/4 | 1.25 | 1-1/8 |
| 20 | 24 | 30-1/2 | 27 | 1.38 | 1-1/4 |
A350 LF2 threaded flanges perform well over a wide range of temperatures especially in service down to -46°C. These flanges are specified to maintain toughness and strength under thermal cycling and fluctuating pressure loads. Their ability to tolerate a wide range of temperatures makes them perfect for LNG plants, and cryogenic pipe systems.
| Nominal Size | Outside Diameter (OD) | Bore Diameter (B) | No. of Bolt Holes | Bolt Hole Diam. | Bolt Circle (BC) | Thickness (T) | Hub Length (L) | Hub Diam. (H) | Lap Radius ( R ) | Approx. Weight (lbs) |
| 1 | 4.25 | 1.38 | 4 | 0.625 | 3.13 | 0.563 | 0.688 | 1.938 | 0.13 | 2 |
| 1 1/4 | 4.68 | 1.72 | 4 | 0.625 | 3.50 | 0.625 | 0.813 | 2.312 | 0.19 | 3 |
| 1 1/2 | 5.00 | 1.97 | 4 | 0.625 | 3.88 | 0.688 | 0.875 | 2.563 | 0.25 | 3 |
| 2 | 6.00 | 2.46 | 4 | 0.750 | 4.75 | 0.750 | 1.000 | 3.063 | 0.31 | 5 |
| 2 1/2 | 7.00 | 2.97 | 4 | 0.750 | 5.50 | 0.875 | 1.125 | 3.563 | 0.31 | 7 |
| 3 | 7.50 | 3.60 | 4 | 0.750 | 6.00 | 0.938 | 1.188 | 4.250 | 0.38 | 8 |
| 3 1/2 | 8.50 | 4.10 | 8 | 0.750 | 7.00 | 0.938 | 1.250 | 4.812 | 0.38 | 11 |
| 4 | 9.00 | 4.60 | 8 | 0.750 | 7.50 | 0.938 | 1.312 | 5.312 | 0.44 | 13 |
| 5 | 10.00 | 5.69 | 8 | 0.875 | 8.50 | 0.938 | 1.438 | 6.438 | 0.44 | 15 |
| 6 | 11.00 | 6.75 | 8 | 0.875 | 9.50 | 1.000 | 1.562 | 7.562 | 0.50 | 18 |
| 8 | 13.50 | 8.75 | 8 | 0.875 | 11.75 | 1.125 | 1.750 | 9.688 | 0.50 | 30 |
| 10 | 16.00 | 10.92 | 12 | 1.000 | 14.25 | 1.188 | 1.938 | 12.000 | 0.50 | 42 |
| 12 | 19.00 | 12.92 | 12 | 1.000 | 17.00 | 1.250 | 2.188 | 14.375 | 0.50 | 64 |
| 14 | 21.00 | 14.19 | 12 | 1.125 | 18.75 | 1.375 | 2.250 | 15.750 | 0.50 | 90 |
| 16 | 23.50 | 16.19 | 16 | 1.125 | 21.25 | 1.438 | 2.500 | 18.000 | 0.50 | 98 |
| 18 | 25.00 | 18.20 | 16 | 1.250 | 22.75 | 1.562 | 2.688 | 19.875 | 0.50 | 125 |
| 20 | 27.50 | 20.25 | 20 | 1.250 | 25.00 | 1.688 | 2.875 | 22.000 | 0.50 | 160 |
| 24 | 32.00 | 24.25 | 20 | 1.375 | 29.50 | 1.875 | 3.250 | 26.125 | 0.50 | 212 |
| 30** | 38.75 | 30.25 | 28 | 1.375 | 36.00 | 2.125 | 3.500 | 32.750 | 0.50 | 305 |
| 36** | 46.00 | 36.25 | 32 | 1.625 | 42.75 | 2.375 | 3.750 | 39.250 | 0.50 | 440 |
| NPS (In) | Dia of Bolts (In) |
Bolt Circle (In) |
No. of Bolts |
Dia of Bolt Holes (In) |
Dia of Flange (In) |
|---|---|---|---|---|---|
| 1/4 | 1/2 | 2-1/4 | 4 | 0.62 | 3-3/8 |
| 1-1/2 | 1/2 | 3-7/8 | 4 | 0.62 | 5 |
| 1 | 1/2 | 3-1/8 | 4 | 0.62 | 4-1/4 |
| 1-1/4 | 1/2 | 3-1/2 | 4 | 0.62 | 4-5/8 |
| 2-1/2 | 5/8 | 5-1/2 | 4 | 0.75 | 7 |
| 3 | 5/8 | 6 | 4 | 0.75 | 7-1/2 |
| 2 | 5/8 | 4-3/4 | 4 | 0.75 | 6 |
| 4 | 5/8 | 7-1/2 | 8 | 0.75 | 9 |
| 5 | 3/4 | 8-1/2 | 8 | 0.88 | 10 |
| 3-1/2 | 5/8 | 7 | 8 | 0.75 | 8-1/2 |
| 8 | 3/4 | 11-3/4 | 8 | 0.88 | 13-1/2 |
| 10 | 7/8 | 14-1/4 | 12 | 1 | 16 |
| 6 | 3/4 | 9-1/2 | 8 | 0.88 | 11 |
| 14 | 1 | 18-3/4 | 12 | 1.12 | 21 |
| 3/4 | 1/2 | 2-3/4 | 4 | 0.62 | 3-7/8 |
| 16 | 1 | 21-1/4 | 16 | 1.12 | 23-1/2 |
| 12 | 7/8 | 17 | 12 | 1 | 19 |
| 20 | 1-1/8 | 25 | 20 | 1.25 | 27-1/2 |
| 1/2 | 1/2 | 2-3/8 | 4 | 0.62 | 3-1/2 |
| 24 | 1-1/4 | 29-1/2 | 20 | 1.38 | 32 |
| 18 | 1-1/8 | 22-3/4 | 16 | 1.25 | 25 |
| Sizes | Schedule | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| NPS | O.D | Schedule 140 | Schedule 160 | Schedule 80 | Schedule 100 | Schedule 30 | Schedule 60 | Schedule 40 | Schedule 10 | Schedule 20 | Schedule 120 |
| 18 | 18 | 1.562 | 1.781 | 0.938 | 1.156 | 0.438 | 0.75 | 0.562 | 0.25 | 0.312 | 1.375 |
| 20 | 20 | 1.75 | 1.969 | 1.031 | 1.281 | 0.5 | 0.812 | 0.594 | 0.25 | 0.375 | 1.5 |
| 14 | 14 | 1.25 | 1.406 | 0.75 | 0.938 | 0.375 | 0.594 | 0.438 | 0.25 | 0.312 | 1.094 |
| 16 | 16 | 1.438 | 1.594 | 0.844 | 1.031 | 0.375 | 0.656 | 0.5 | 0.25 | 0.312 | 1.219 |
| 6 | 6.625 | – | 0.719 | 0.432 | – | – | – | 0.28 | 0.134 | – | 0.562 |
| 8 | 8.625 | 0.812 | 0.906 | 0.5 | 0.594 | 0.277 | 0.406 | 0.322 | 0.148 | 0.25 | 0.719 |
| ¾ | 1.05 | – | 0.219 | 0.154 | – | – | – | 0.113 | 0.083 | – | – |
| ½ | 0.84 | – | 0.188 | 0.147 | – | – | – | 0.109 | 0.083 | – | – |
| 1 | 1.315 | – | 0.25 | 0.179 | – | – | – | 0.133 | 0.109 | – | – |
| 5 | 5.563 | – | 0.625 | 0.375 | – | – | – | 0.258 | 0.134 | – | 0.5 |
| 2 | 2.375 | – | 0.344 | 0.218 | – | – | – | 0.154 | 0.109 | – | – |
| 1 ½ | 1.9 | – | 0.281 | 0.2 | – | – | – | 0.145 | 0.109 | – | – |
| 4 | 4.5 | – | 0.531 | 0.337 | – | – | – | 0.237 | 0.12 | – | 0.438 |
| 3 ½ | 4 | – | – | 0.318 | – | – | – | 0.226 | 0.12 | – | – |
| 10 | 10.75 | 1 | 1.125 | 0.594 | 0.719 | 0.307 | 0.5 | 0.365 | 0.165 | 0.25 | 0.844 |
| 12 | 12.75 | 1.125 | 1.312 | 0.688 | 0.844 | 0.33 | 0.562 | 0.406 | 0.18 | 0.25 | 1 |
| 3 | 3.5 | – | 0.438 | 0.3 | – | – | – | 0.216 | 0.12 | – | – |
| 2 ½ | 2.875 | – | 0.375 | 0.276 | – | – | – | 0.203 | 0.12 | – | – |
| 1 ¼ | 1.66 | – | 0.25 | 0.191 | – | – | – | 0.14 | 0.109 | – | – |
| Property | Value |
|---|---|
| Density | 7.85 g/cm³ |
| Modulus of Elasticity | 210 GPa |
| Hardness(Rockwell B h) | ≤ 95 |
| Thermal Conductivity | 50 W/m·K |
| Coefficient of Thermal Expansion | 12 x 10^-6 /°C |
ASTM A350 LF2 Flanges Certifications & Compliance
Midland Alloys Inc. is an ISO 9001:2015, ISO 14001:2015, ISO 45001:2018, and PED 2014/68/EU certified manufacturer and exporter of ASTM A350 LF2 flanges. Our products goes through strict in-house tests and third-party audits. We provide flanges along with relevant Mill Test Certificates, test reports that have been certified by NABL and thorough traceability records.
ASTM A350 LF2 Flanges Grades We Offer
Plate
Shear
Press
Inspection
Lathe
Drilling
Cleaning
Flange
Inspection
Analytic
Marking
Packing & Shipping
Industrial Applications
ASTM A350 LF2 flanges are used extensively in industries that require strength as well as cold-temperature resistance. The pharmaceutical industry, oil and gas pipelines, power generation applications, heat exchangers, chemical and petrochemical plants, food and beverage processing and HVAC equipment are among the industries that use these flanges. Their good low-temperature properties, toughness and adherence to safety requirements make them suitable for use in critical processes like LNG processing, offshore drilling, and subzero transportation systems.
Testing & Packaging
To ensure its reliability and quality, our flanges go through an extensive range of testing, including as Visual Inspection, Hydrostatic Testing, Ultrasonic Testing, and Positive Material Identification (PMI). To verify structural integrity, both destructive and non-destructive tests are conducted. To prevent our products from damage during transit, we use safe export packaging, such as labeled boxes, plastic wrap and wooden crates. For easy traceability, each shipment includes the proper identification tags and documentation.
Why Choose Us
Midland Alloys Inc. is an ISO 9001, PED and IBR certified manufacturer known for quality consistency, and reliability. Our global export network ensures on-time delivery across continents. We provide custom lengths, finishes and flange configuration, that meet the project requirements. We offer material tracking in real-time and support, along with 24/7 customer service. In order to meet industry standards, we consistently invest in cutting-edge production technologies, a knowledgeable personnel and strict quality control. We are the first choice among engineers, and project managers looking for long term supply arrangements.
FAQ
ASTM A350 LF2 flanges are perfect for cryogenic, and subzero applications since, they can withstand temperatures as low as -50°F (-46°C).
Yes, these flanges may be manufactured using regular techniques, and have good weldability.
Yes, especially for Class 1 material, Charpy V-notch impact testing is required to verify toughness at low temperatures.
