Butt Welding LR 90D Elbow Super Duplex 2507 UNS S32750 1-1/2" SCH10 ANSI B16.9

1. Product Description

This product is a 90-degree Long Radius (LR) butt-welding elbow manufactured from Super Duplex 2507 (UNS S32750 / F53) stainless steel in accordance with ASTM A815 and ASME B16.9 standards. Super Duplex 2507 is a high-alloy duplex stainless steel with a dual-phase microstructure of approximately 50% ferrite and 50% austenite, characterized by a PREN value exceeding 40. The LR design features a radius of curvature equal to 1.5 times the pipe diameter (R = 1.5D), ensuring smooth fluid flow with minimal pressure loss. This 1-1/2" SCH10 fitting is designed for permanent butt-weld connection in demanding industrial piping systems requiring exceptional strength and corrosion resistance.

2. Key Product Parameters

3. Application / Usage

This 90° LR elbow is ideal for extremely aggressive and high-stress environments:

• Oil & Gas: Offshore platforms, subsea piping systems, wellhead connections, seawater injection lines, sour gas service (NACE MR0175 compliant)

• Chemical Processing: Chloride-containing acids, heat exchangers, high-pressure process lines

• Marine & Desalination: Seawater piping, reverse osmosis systems, brine handling

• Power Generation: Cooling water systems, condenser piping

• Pulp and Paper: Bleaching lines, digesters

4. Advantages

• Superior Strength: Yield strength (550-800 MPa) is approximately 2.5 to 3 times that of 316L, enabling thinner walls and lighter piping systems

• Exceptional Corrosion Resistance: PREN ≥ 40 provides outstanding resistance to pitting, crevice corrosion, and chloride stress corrosion cracking (SCC)

• Superior to 2205: Outperforms standard duplex 2205 in both corrosion resistance and mechanical strength

• Long Radius Design: R=1.5D minimizes pressure drop, turbulence, and erosion

• Wide Temperature Range: Maintains properties from -50°C to 300°C

5. Functions

The 90° LR elbow changes the direction of fluid flow within a piping system by 90 degrees with minimal pressure loss. The long radius design (R=1.5D) reduces flow resistance, turbulence, and erosion, making it suitable for high-velocity and corrosive media applications. The butt-weld connection provides a permanent, leak-proof joint with high structural integrity for critical service environments.

6. Installation Instructions

1. Unpacking Inspection: Check for transit damage; verify markings, dimensions, and material certification per ASME B16.9

2. Surface Preparation: Clean the weld bevel and adjacent area using dedicated stainless steel tools; remove all oil, grease, and contaminants

3. Alignment: Accurately align the elbow with connecting pipes, ensuring proper fit-up

4. Tack Welding: Apply minimum tack welds to hold the assembly in position; clean thoroughly before final welding

5. Welding: Perform butt-weld following approved WPS with certified welders. For Super Duplex 2507, strict heat input control is essential. Use GTAW or SMAW with matching filler metal ER2594. Heat input must be maintained within 0.5 to 1.5 kJ/mm. Interpass temperature must be maintained ≤100°C to 150°C to prevent detrimental phase formation. Preheating generally not required

6. Post-Weld Treatment: Solution annealing at 1020-1120°C followed by water quenching is required to restore the duplex structure and corrosion resistance

7. Inspection: Perform NDT (PT/MT, UT) as per project requirements. Ferrite content verification per ASTM E562 is recommended

7. Precautions

• Temperature Limitation: Not recommended for use above 300°C; prolonged exposure above 316°C may cause embrittlement

• Ferrite Balance: Ensure ferrite content remains between 40-60%. Improper heat treatment is the most common cause of out-of-spec ferrite ratios

• Intermetallic Phase Sensitivity: Super duplex welds are sensitive to sigma and chi phase formation; tight heat input control is mandatory

• Cleanliness: Requires a higher degree of cleanliness than carbon steel fabrication; use dedicated tools to prevent contamination

• Corrosion Testing: ASTM A923 Method C testing is standard for verifying corrosion resistance

• NACE Compliance: For sour gas service, confirm compliance with NACE MR0175 requirements

8. Shipping & Delivery

• Standard delivery time is typically 7–30 days, subject to order quantity and specification availability

9. Payment Terms

• Common international payment methods include T/T (Telegraphic Transfer) and L/C at sight (Letter of Credit)

10. Packaging

Products are securely packed in plywood cases or wooden crates with internal cushioning to ensure safe transportation and prevent damage during transit.