We make ASTM A350 GR. LF2 CL.1 flanges from forged carbon steel, specifically for low-temperature (cryogenic) use.
The main thing that sets these flanges apart is they have to pass a strict impact test at -46℃ (-50℉) - that's non-negotiable for their intended use.
They're super common in industries like LNG, petrochemicals, and refrigeration, where cold-temperature piping systems need reliable parts.
These flanges adhere to ASTM A350 / ASME SA350 standards, which cover carbon and low-alloy steel forgings for cold service.
They're graded LF2, Class 1 (CL.1) - the CL.1 means they meet the -46℃ impact requirement.
For dimensions, we go by ASME B16.5 (for sizes 1/2" to 24"), ASME B16.47 (26" to 60"), and MSS SP-44.
At -46℃, the flanges need a minimum impact energy of 15 ft-lbs (around 20 J) to pass testing.
Room-temperature performance: tensile strength is 485–655 MPa, yield strength at least 250 MPa, elongation 22% or more, and hardness max HB 197.
We use two heat treatment methods: either normalizing (860–920℃, air-cooled) or quenching and tempering (890–940℃ quench, 540–665℃ temper for 30+ minutes).
Pressure classes available: 150, 300, 400, 600, 900, 1500, 2500.
Sizes range from 1/2" up to 60" (following ASME B16.5 and B16.47).
Flange types we offer: Weld Neck (WN), Slip-On (SO), Socket Weld (SW), Lap Joint (LJ), Threaded (TH), Blind (BL).
Sealing face options: Raised Face (RF), Flat Face (FF), Ring Type Joint (RTJ).
These flanges are used in LNG receiving terminals and LNG pipelines, petrochemical cryogenic process lines (like ethylene or propylene plants), industrial refrigeration systems, cryogenic storage tanks, air separation equipment, and any pressure piping that needs to handle -46℃ or colder.
CL.1 is for cold environments - it's tested at -46℃ and works well at that temperature or lower.
CL.2 is for milder low temperatures - tested at -18℃ and suitable for use at -18℃ or higher.
We stand by every ASTM A350 GR. LF2 CL.1 flange we make-they're all built strictly to ASTM A350 international standards, no shortcuts, no cutting corners.
Every batch comes with an authoritative third-party test report and our factory quality certificate, laying out all the key details: chemical composition, mechanical properties, low-temperature impact test results, everything you need to verify quality.
If there's any quality problem that's our fault-whether it's from production or materials-we'll replace the product without hesitation, and cover any necessary compensation.
And we promise to give you the most competitive wholesale prices, too-all while keeping the quality you can trust.
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