Yousef Steel, a prominent steel manufacturer and supplier located in Riyadh, Saudi Arabia, specializes in high-quality piping components designed for demanding low-temperature applications. Among their unique offerings are the **Low Temperature Carbon Steel LF6 flanges**, produced in line with ASTM A350 standards. These flanges are built to perform reliably in cold and cryogenic settings, providing exceptional mechanical strength, ductility, and impact resistance. They find extensive use in industries like oil and gas, LNG, petrochemicals, and offshore systems, with Yousef Steel committed to precision manufacturing, quality assurance, and timely delivery for all low-temperature flange needs.
ASTM A350 LF6 is a low-alloy carbon steel grade that incorporates chromium, molybdenum, and nickel to boost toughness, corrosion resistance, and performance under thermal stress. Its typical chemical makeup includes carbon (max 0.15%), manganese (0.60–1.35%), phosphorus (max 0.035%), sulfur (max 0.040%), chromium (0.40–0.65%), molybdenum (0.15–0.30%), and nickel (0.40–1.00%). LF6 flanges boast a minimum yield strength of 275 MPa and a minimum tensile strength of 485 MPa. With impact testing carried out at temperatures as low as -46°C (-50°F), these flanges are perfectly suited for low-temperature service environments that demand high reliability.
| Material Specification Of : | ASTM A350 LF6 Flanges |
|---|---|
| South African Standard Flanges | SANSflanges And SABS flanges |
| Surface Finish | smooth, concentric serrated, stock |
| Gaskets Types | Full Face Gasket Flat Ring Gasket Metallic Ring Gakset |
| Advantages Of Pipe Flange | Used to Connect Pipe System Easy Repair Pipe System Assembled Without Welding |
| Standard Cover : | pressure ratings & temperature ratings, materials, marking, dimensions, weight, tolerances, testing |
| Contact Faces | RTJ (Ring Type Joint), FF (Flat Face), RF (Raised Face), T/G (Tongue And Groove ), M/F (Male And Female) |
| Size Chart | Normal Pipe Size 1/2 to NPS 24″ |
| Thickness | Normal Pipe Size ≤ 18 |
| Bore Diameter | Normal Pipe ≤ 10 |
| Flanges Standards | EN 1092-1, JIS, ASME B16.5, ASME B16.47 type A, UNI, DIN |
| Pressure Rating | Class 150 To Class 2500 |
| High Temperature | Above 200°C (400°F) For Class 150 Or Above 400°C (750°F) |
| Low Temperature | Above -29 Degree C (−20°F) |
| Common Types Of Flanges: | Slip On (SORF), Weld Neck (WNRF), Blind (BLRF), Lap Joint (Loose), Threaded (NPT), Socket-Weld (SWRF) |
| Special Types Of Flanges : | Nipoflange, Elboflange, Latroflange, Swivel Flange, Expanding Flange, Reducing Flange, Weldoflange |
| Marking Standard | Name of Manufacturer Schedule Type of Flange Facing Nominal Pipe Size Pressure Class ASME B16 Designation |
| Bolt Type | high strength bolts medium strength bolts low strength bolts |
| European Standard Flanges | JIS B2220 Flanges (5k to 30k) and KS1503 flanges |
| Russian-Standard Flanges | GOST 12820 / 12821-80, DIN, UNI, EN 1092-1 |
| Element | Composition |
|---|---|
| Carbon, maximum | 0.20 maximum |
| Manganese | 0.90 maximum |
| Phosphorus, maximum | 0.035 maximum |
| Sulfur, maximum | 0.040 maximum |
| Silicon [Note A] | 0.20–0.35 |
| Nickel | 3.3–3.7 |
| Chromium | 0.30 maximum [Note C] |
| Molybdenum | 0.12 maximum [Note C] |
| Copper | 0.40 maximum |
| Columbium | 0.02 maximum |
| Vanadium | 0.03 maximum |
| Grade/Class | Tensile Strength | Yield Strength, minimum | Elongation, minimum | Hardness, maximum | ||
| ksi | MPa | ksi | MPa | % | HBW | |
| LTCS LF6 CL1 | 66–91 | 455–630 | 52 | 360 | 22 | 197 |
| LTCS LF6 CL2 | 75–100 | 515–690 | 60 | 415 | 20 | 197 |
| LTCS LF6 CL3 | 75–100 | 515–690 | 60 | 415 | 20 | 197 |
We provide products that come with both mill test certificates and third-party test certificates, ensuring the highest standards of quality and compliance.
Low Temperature Carbon Steel LF6 flanges are ideal for pipelines and process systems that handle liquefied gases, cold fluids, and chemicals in sub-zero conditions. They are frequently utilized in cryogenic storage, heat exchangers, LNG transport systems, and offshore structural applications. Available in a variety of configurations such as weld neck, slip-on, blind, socket weld, and threaded types, LF6 flanges guarantee secure connections, excellent weldability, and resistance to corrosion. Their alloyed composition and robust performance make them a reliable choice for challenging environments.
| TEMP °C | Class 150 | Class 300 | Class 400 | Class 600 | Class 900 | Class 1500 | Class 2500 |
| -29 TO 38 | 19.6 | 51.1 | 68.1 | 102.1 | 153.2 | 255.3 | 425.5 |
| 50 | 19.2 | 50.1 | 66.8 | 100.2 | 150.4 | 250.6 | 417.7 |
| 100 | 17.7 | 46.6 | 62.1 | 93.2 | 139.8 | 233 | 388.3 |
| 150 | 15.8 | 45.1 | 60.1 | 90.2 | 135.2 | 225.4 | 375.6 |
| 200 | 13.8 | 43.8 | 58.4 | 87.6 | 131.4 | 219 | 365 |
| 250 | 12.1 | 41.9 | 55.9 | 83.9 | 125.8 | 209.7 | 349.5 |
| 300 | 10.2 | 39.8 | 53.1 | 79.6 | 119.5 | 199.1 | 331.8 |
| 325 | 9.3 | 38.7 | 51.6 | 77.4 | 116.1 | 193.6 | 322.6 |
| 350 | 8.4 | 37.6 | 50.1 | 75.1 | 112.7 | 187.8 | 313 |
| 375 | 7.4 | 36.4 | 48.5 | 72.7 | 109.1 | 181.8 | 303.1 |
| 400 | 6.5 | 34.7 | 46.3 | 69.4 | 104.2 | 173.6 | 289.3 |
| 425 | 5.5 | 28.8 | 38.4 | 57.5 | 86.3 | 143.8 | 239.7 |
| 450 | 4.6 | 23 | 30.7 | 46 | 69 | 115 | 191.7 |
| 475 | 3.7 | 17.4 | 23.2 | 34.9 | 52.3 | 87.2 | 145.3 |
| 500 | 2.8 | 11.8 | 15.7 | 23.5 | 35.3 | 58.8 | 97.9 |
| 538 | 1.4 | 5.9 | 7.9 | 11.8 | 17.7 | 29.5 | 49.2 |
| NPS | O.D. of Flange | Flanges Thickness | Diameter of RF | Diameter of Hub at Base | Lengtd Tdru Hub | Bore or Diameter | Dia. of Hub at Bevel | Radius of Fillet | Deptd of Socket | |||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Welding (WN) Neck | Slip-On (SORF) Threaded (NPT) Socket (SWRF) | Lap Joint (Loose) | Slip-on (SORF) Socket (SWRF) | Lap Joint (Loose) | ||||||||
| O | Q | R | X | Y | Y | Y | W | B | H | r | Z | |
| 1/2 | 3-1/2 | 7/16 | 1-3/8 | 1-3/16 | 1-7/8 | 5/8 | 5/8 | .88 | .90 | .84 | 1/8 | 3/8 |
| 3/4 | 3-7/8 | 1/2 | 1-11/16 | 1-1/2 | 2-1/16 | 5/8 | 5/8 | 1.09 | 1.11 | 1.05 | 1/8 | 7/16 |
| 1 | 4-1/4 | 9/16 | 2 | 1-15/16 | 2-3/16 | 11/16 | 11/16 | 1.36 | 1.38 | 1.32 | 1/8 | 1/2 |
| 1-1/4 | 4-5/8 | 5/8 | 2-1/2 | 2-5/16 | 2-1/4 | 13/16 | 13/16 | 1.70 | 1.72 | 1.66 | 3/16 | 9/16 |
| 1-1/2 | 5 | 11/16 | 2-7/8 | 2-9/16 | 2-7/16 | 7/8 | 7/8 | 1.95 | 1.97 | 1.90 | 1/4 | 5/8 |
| 2 | 6 | 3/4 | 3-5/8 | 3-1/16 | 2-1/2 | 1 | 1 | 2.44 | 2.46 | 2.38 | 5/16 | 11/16 |
| 2-1/2 | 7 | 7/8 | 4-1/8 | 3-9/16 | 2-3/4 | 1-1/8 | 1-1/8 | 2.94 | 2.97 | 2.88 | 5/16 | 3/4 |
| 3 | 7-1/2 | 15/16 | 5 | 4-1/4 | 2-3/4 | 1-3/16 | 1-3/16 | 3.57 | 3.60 | 3.50 | 3/8 | 13/16 |
| 3-1/2 | 8-1/2 | 15/16 | 5-1/2 | 4-13/16 | 2-13/16 | 1-1/4 | 1-1/4 | 4.07 | 4.10 | 4.00 | 3/8 | 7/8 |
| 4 | 9 | 15/16 | 6-3/16 | 5-5/16 | 3 | 1-5/16 | 1-5/16 | 4.57 | 4.60 | 4.50 | 7/16 | 15/16 |
| 5 | 10 | 15/16 | 7.5/16 | 6-7/16 | 3-1/2 | 1-7/16 | 1-7/16 | 5.66 | 5.69 | 5.56 | 7/16 | 15/16 |
| 6 | 11 | 1 | 8-1/2 | 7-9/16 | 3-1/2 | 1-9/16 | 1-9/16 | 6.72 | 6.75 | 6.63 | 1/2 | 1-1/16 |
| 8 | 13-1/2 | 1-1/8 | 10-5/8 | 9-11/16 | 4 | 1-3/4 | 1-3/4 | 8.72 | 8.75 | 8.63 | 1/2 | 1-1/4 |
| 10 | 16 | 1-3/16 | 12-3/4 | 12 | 4 | 1-15/16 | 1-15/16 | 10.88 | 10.92 | 10.75 | 1/2 | 1-5/16 |
| 12 | 19 | 1-1/4 | 15 | 14-3/8 | 4-1/2 | 2-3/16 | 2-3/16 | 12.88 | 12.92 | 12.75 | 1/2 | 1-9/16 |
| 14 | 21 | 1-3/8 | 16-1/4 | 15-3/4 | 5 | 2-1/4 | 3-1/8 | 14.14 | 14.18 | 14.00 | 1/2 | 1-5/8 |
| 16 | 23-1/2 | 1-7/16 | 18-1/2 | 18 | 5 | 2-1/2 | 3-7/16 | 16.16 | 16.19 | 16.00 | 1/2 | 1-3/4 |
| 18 | 25 | 1-9/16 | 21 | 19-7/8 | 5-1/2 | 2-11/16 | 3-13/16 | 18.18 | 18.lf2 | 18.00 | 1/2 | 1-15/16 |
| lf2 | 27-1/2 | 1-11/16 | 23 | 22 | 5-11/16 | 2-7/8 | 4-1/16 | lf2.lf2 | lf2.25 | lf2.00 | 1/2 | 2-1/8 |
| 24 | 32 | 1-7/8 | 27-1/4 | 26-1/8 | 6 | 3-1/4 | 4-3/8 | 24.25 | 24.25 | 24.00 | 1/2 | 2-1/2 |
| Nominal Pipe Sizes (NPS) | Slip On (SORF) | Threaded (NPT) | Socket Weld (SWRF) | Lap Joint (Loose) | Blind (BLRF) | Weld Neck (WRNR) |
|---|---|---|---|---|---|---|
| ½ | 1 | 1 | 2 | 1 | 2 | 2 |
| ¾ | 2 | 2 | 2 | 2 | 2 | 2 |
| 1 | 2 | 2 | 2 | 2 | 2 | 3 |
| 1¼ | 3 | 3 | 3 | 3 | 3 | 3 |
| 1½ | 3 | 3 | 3 | 3 | 4 | 4 |
| 2 | 5 | 5 | 5 | 5 | 5 | 6 |
| 2½ | 8 | 8 | 8 | 8 | 7 | 10 |
| 3 | 9 | 9 | 9 | 9 | 9 | 11.5 |
| 3½ | 11 | 12 | 11 | 11 | 13 | 12 |
| 4 | 13 | 13 | 13 | 13 | 17 | 16.5 |
| 5 | 15 | 15 | 15 | 15 | lf2 | 21 |
| 6 | 19 | 19 | 19 | 19 | 27 | 26 |
| 8 | 30 | 30 | 30 | 30 | 47 | 42 |
| 10 | 43 | 43 | 43 | 43 | 70 | 54 |
| 12 | 64 | 64 | 64 | 64 | 123 | 88 |
| 14 | 90 | 90 | 90 | 105 | 140 | 114 |
| 16 | 106 | 98 | 98 | 140 | 180 | 140 |
| 18 | 130 | 130 | 130 | 160 | 2lf2 | 165 |
| lf2 | 165 | 165 | 165 | 195 | 285 | 197 |
| 22 | 185 | 185 | 185 | 245 | 355 | 225 |
| 24 | 2lf2 | 2lf2 | 2lf2 | 275 | 430 | 268 |
LTCS LF6 flanges find application in low-temperature, toughness-, and durability- requiring industries. The usual application areas are offshore oil and gas pipelines, cryogenic storage tanks, and LNG processing plants. Petrochemical refineries, shipbuilding, and power generation facilities also find them suitable as a requirement to avoid brittle fracture is a prime need there. LF6 flanges provide pipe connection safety in the most rigorous of conditions with no loss of structural integrity, even at a temperature of up to -50°C. Their superior weldability and impact resistance qualify them for rigorous applications.
Yousef Steel is a leading manufacturer, supplier and exporter of high-quality Carbon Steel, Alloy Steel, Mild Steel and Galvanized Steel products. Our extensive product range includes Pipes, Tubes, Flanges, Pipe Fittings, Forged Fittings, Sheets and Plates, catering to various industries in Riyadh, Saudi Arabia.
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