Stainless Steel 316L Thread Weld Union Pipe Fittings

XINHUAFENG’s Stainless Steel 316L Thread Weld Union Pipe Fittings are premium piping components engineered for reliability and performance in demanding industrial environments. As a core product line, these Thread Weld Union Pipe Fittings for SS integrate precision threading and welding design, delivering leak-proof connections and exceptional durability.

Crafted from high-quality 316L stainless steel (with 304 variants available), our 304 316L Thread Weld Union Pipe Fittings excel in corrosion resistance, making them ideal for harsh media, high temperatures, and high-pressure applications. Whether used in chemical processing, oil & gas, or water treatment systems, these Stainless Steel Thread Weld Union Pipe Fittings meet global industrial standards, ensuring seamless compatibility with standard Pipe Fittings and piping infrastructures.

• Material: 316L stainless steel (UNS S31603), optional 304 stainless steel (UNS S30400)
• Product Type: Thread weld union, Socket Weld Fittings, Buttweld Fitting alternatives available
• Thread Standards: NPT, BSPP, BSPT, DIN, ISO, and custom thread specifications
• Size Range: 1/8" to 4" (DN6 to DN100), larger sizes available on request
• Pressure Rating: Class 150, 300, 600 (PN10, PN16, PN25, PN40)
• Temperature Range: -270°C to +550°C (-454°F to +1022°F)
• Corrosion Resistance: Excellent resistance to chlorides, acids, alkalis, and marine environments
• Surface Finish: Pickled and passivated (standard), polished (Ra ≤ 0.8μm, optional)
• Dimensions: Compliant with ASME B16.11, DIN 2999, EN 10241, JIS B2316
• Mechanical Properties: Tensile strength ≥ 485 MPa, yield strength ≥ 170 MPa, elongation ≥ 40%

• Premium 316L/304 stainless steel construction for superior corrosion resistance
• Precision-threaded connections for tight, leak-proof assembly
• Integrated weld union design for easy installation and maintenance
• High-pressure and high-temperature tolerance for extreme working conditions
• Smooth internal surface to minimize fluid resistance and pressure drop
• Compatible with standard Pipe Fittings and industrial piping systems

1. Enhanced Durability: 316L stainless steel offers 2x better corrosion resistance than 304, extending service life to 15-20 years in harsh environments.
2. Precision Manufacturing: CNC machining ensures thread accuracy within ±0.01mm, reducing assembly errors and leakage risks.
3. Cost-Efficiency: Low maintenance requirements and long service life reduce replacement costs by up to 40% compared to ordinary pipe fittings.
4. Versatile Installation: Dual-thread and weld design adapts to both threading and welding assembly methods, meeting diverse project needs.
5. Global Standard Compliance: Manufactured to international standards, ensuring seamless integration into global supply chains.

The thread weld union design combines the reliability of threaded connections with the strength of welding. The fitting features precision internal threads for initial secure assembly, followed by welding around the union joint to create a permanent, leak-proof seal. This dual-security structure prevents loosening under vibration and maintains structural integrity even in high-pressure systems, ensuring stable fluid or gas transmission.

1. Prepare Piping: Cut the pipe to the required length and deburr both inner and outer surfaces to remove sharp edges that may affect sealing.
2. Clean Surfaces: Wipe the pipe ends and fitting threads with a non-residue solvent to remove oil, dirt, or debris.
3. Apply Sealant: Apply high-temperature thread sealant or PTFE tape to the male threads (avoid excess sealant to prevent clogging).
4. Assemble Fitting: Hand-tighten the union fitting onto the pipe, then use a wrench to torque to the recommended value (refer to technical specifications).
5. Weld Joint: Position the welding torch at a 45° angle to the union joint, applying even heat to create a full penetration weld. Allow the joint to cool naturally.
6. Leak Test: Conduct a pressure test (air or water) at 1.5x the working pressure to verify seal integrity before system operation.

Our Stainless Steel 316L Thread Weld Union Pipe Fittings are widely used in industries requiring high-performance Pipe Fittings that withstand harsh conditions: