MSS SP 83 A350 LF2 Pipe Unions
MSS SP-83 A350 LF2 Pipe Unions are pipeline quick-connect couplings compliant with the MSS SP-83 standard, manufactured from ASTM A350 LF2 low-temperature carbon steel. Designed for low-temperature and high-pressure environments, they are ideal for demanding applications in oil, gas, and chemical industries.
High Quality MSS SP 83 A350 LF2 Pipe Unions
- Pressure Rating: Class 3000 and 6000
- Size Range: typically NPS 1/8″ to 4″
- Types: socket weld and threaded unions.
Key Features
- Cryogenic Toughness: ASTM A350 LF2 resists impact down to -46°C, preventing brittle failure.
- High Pressure: Rated for Class 3000/6000 systems.
- Quick Assembly: No welding tools needed.
- Compatibility: Pairs with ASTM A350 LF2 flanges, valves, and fittings.
Material Properties (ASTM A350 LF2)
- ASTM A350 LF2: A low-temperature carbon steel forging material with excellent toughness at cryogenic temperatures (service range: -46°C to +343°C), ideal for harsh environments (e.g., Arctic pipelines, LNG systems).
- Contains nickel (Ni) and molybdenum (Mo) to enhance impact resistance and prevent brittle fracture.
- Surface treatments (e.g., galvanizing) may be applied for corrosion protection.
Structure & Types
Three-Piece Design:
- Consists of two threaded or socket weld ends (male/female) and a central nut for quick assembly/disassembly.
- Sealing: Metal-to-metal contact (no gasket), relying on precision machining for leak-proof performance.
Connection Types:
- Threaded Unions: Use NPT threads for pipe connections.
- Socket Weld Unions: Welded to pipes for higher-pressure applications.
Pressure Ratings:
- Class 3000 (~750 psi) and Class 6000 (~1500 psi). Pressure-temperature ratings are defined in standard tables.
Typical Applications
Cryogenic Services: LNG, liquid nitrogen (LN2), and low-temperature chemical transport.
High-Pressure Systems: Oil/gas wellheads, Arctic pipelines.
Frequent Maintenance: Instrumentation lines, compressor stations requiring regular access.
One-Stop MSS SP 83 A350 LF2 Pipe Unions Provider for All Your Needs
SSM has significant product advantages in manufacturing MSS SP 83 A350 LF2 Pipe Unions. Whether it’s quality or price, we will meet your needs.
More Information about MSS SP 83 A350 LF2 Pipe Unions
Forging Process: ASTM A350 LF2 requires strict forging for density and low-temperature properties.
Heat Treatment: Normalized or quenched + tempered for optimal strength.
Testing:
- Charpy V-notch impact tests (validates toughness at low temps).
- Chemical analysis (ensures Ni/Mo content).
- Hydrostatic testing (per MSS SP-83).
Selection Guidelines
Temperature Limits:
- Use only within -46°C to +343°C. For higher temps, switch to A105 or alloy steels.
Media Compatibility:
- Avoid strong acids (e.g., sulfuric/hydrochloric acid); use stainless steel (e.g., 316L) instead.
Installation:
- Threaded joints require cryogenic-rated sealant (standard tape may fail in cold).
- Socket welding must maintain a 1.6mm gap to prevent cracking.
Comparison with Other Materials
| Aspect | A350 LF2 | A105 (Carbon Steel) |
| Temp. Range | -46°C to +343°C | -29°C to +425°C |
| Low-Temp. Performance | Excellent (Ni/Mo alloyed) | Poor (prone to brittleness) |
| Typical Uses | LNG, Arctic pipelines, cryogenic chemicals | Steam systems, general oil/gas |
| Cost | Higher (alloy content) | Lower |
FAQ
Threaded Unions:
Apply thread sealant (e.g., Teflon tape).
Tighten the central nut to compress the metal-to-metal seal.
Socket Weld Unions:
Weld pipes into the socket ends, ensuring a 1.6mm gap to prevent stress cracking.
- Operating Range: -46°C (-50°F) to +343°C (+650°F)
- Special Feature: Excellent impact resistance at sub-zero temperatures, making them ideal for LNG, liquid nitrogen, and Arctic pipeline systems.
MSS SP-83 A350 LF2 Pipe Unions are specialized for low-temperature, high-pressure piping systems, such as LNG and Arctic oil/gas applications. Their strengths are cryogenic toughness and high-pressure resistance, though they cost more and are unsuitable for corrosive media. Always verify temperature/pressure compatibility and ensure ASTM A350 LF2 material certifications.
📞 Technical Support: Available for material selection consultation and rapid quotations!
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