Super Duplex Stainless Steel Pipe Fittings Supplied to Russia for Low-Temperature Service

Haihao Group has successfully delivered a batch of super duplex stainless steel pipe fittings to a Russian customer, manufactured from ASTM A815 Grade WPS32750 (UNS S32750). The supplied fittings include long radius elbows and concentric reducers, designed for high-strength, corrosion-resistant, and low-temperature applications in demanding oil and gas environments.

All products were manufactured in full compliance with ASME B16.9, with strict mechanical, corrosion, and microstructural testing to meet international project specifications.

Supplied Pipe Fittings Overview

The shipment covered the following butt-weld fittings:

• 90° Long Radius Elbow, 6″ SCH XXS
  OD × WT: 168.3 × 21.95 mm
  Radius: 1.5D
  Standard: ASME B16.9
  Material: ASTM A815 Gr. WPS32750
• 45° Long Radius Elbow, 6″ SCH XXS
  OD × WT: 168.3 × 21.95 mm
  Standard: ASME B16.9
  Material: ASTM A815 Gr. WPS32750
• 90° Long Radius Elbow, 8″ SCH XXS
  OD × WT: 219.1 × 22.23 mm
  Standard: ASME B16.9
  Material: ASTM A815 Gr. WPS32750
• Concentric Reducer, 8″ × 6″ SCH XXS
  OD × WT: 219.1 × 22.23 mm to 168.3 × 21.95 mm
  Standard: ASME B16.9
  Material: ASTM A815 Gr. WPS32750

These fittings are suitable for high-pressure piping systems requiring excellent resistance to chloride corrosion and sour service conditions.

A815 Gr. WPS32750 stainless steel pipe fittings manufactured by Haihao Group

Material Performance and Mechanical Properties

The supplied UNS S32750 super duplex stainless steel fittings were produced to meet strict chemical and mechanical requirements:

• Pitting Resistance Equivalent (PRE):
  (%Cr + 3.3 × %Mo + 16 × %N) ≥ 40.0
• Tensile Properties (Base Material):
  • Rp0.2 ≥ 550 MPa
  • Rm ≥ 800 MPa
• Hardness Limit:
  Maximum 32 HRC (or 301 HB / 330 HV10), applicable to base material, heat-affected zone, and weld metal

These properties ensure long-term reliability in low-temperature and corrosive service environments.

Impact, Corrosion, and Microstructure Testing

To ensure safety and performance, Haihao Group implemented a comprehensive testing program:

• Charpy V-notch impact testing per ASTM A370 at –46°C, with minimum absorbed energy of 45 J average / 35 J single
• Corrosion testing per ASTM G48 Method A at 50°C for 24 hours
  • No pitting at 20× magnification
  • Weight loss < 4.0 g/m²
• Microstructural examination per ASTM E562
  • Ferrite content:
    • Base metal: 35–55%
    • Weld metal: 25–60%
  • No intermetallic phases or harmful precipitates at 400× magnification

All tests were performed on samples fully representative of the actual fittings supplied.

Welding, NDT, and Dimensional Control

• • Welding procedures qualified according to ASME IX or EN ISO 15614 / EN 288-3
  • Liquid penetrant testing (PT) applied to:
    • 10% of seamless fittings
    • 100% of welded fittings (weld area only)

• Dimensional tolerances controlled according to MSS SP-75, with maximum wall thickness deviation of 0.3 mm
• Surface condition: white pickled finish
• Defect repair on base material was not permitted, ensuring structural integrity

Each fitting was permanently marked for full traceability, from melting to heat treatment batch.

Reliable Supplier of Super Duplex Pipe Fittings

With extensive experience supplying ASTM A815 super duplex stainless steel fittings to international energy projects, Haihao Group is a trusted manufacturer for:

• ASME B16.9 elbows and reducers
• UNS S32750 pipe fittings
• Low-temperature and sour service piping systems
• Russian and international oil & gas projects

Our strict quality control and testing capabilities ensure consistent performance in the most demanding applications.