Stainless Steel Fittings ASTM A403 WPS31254-S 90°LR 45°LR ELBOW B16.9
1. Standard Specification: ASTM A403
Stainless steel piping fittings, including elbows, tees, reducers, and caps.
It ensures compliance with mechanical properties, chemical composition, and testing requirements.
2. Material Grade: WP S31254 (UNS S31254)
- WP stands for "Wrought Product," indicating the fitting is made from wrought stainless steel.
- S31254 corresponds to UNS S31254 (254 SMO), a super austenitic stainless steel with high corrosion resistance due to:
20% Chromium, 18% Nickel, 6% Molybdenum, 0.2% Nitrogen.
- Excellent performance in aggressive environments (e.g., seawater, chlorides, acids).
3. Elbow Specifications
- 90°LR and 45°LR: Elbows with Long Radius (LR) bends.
Long Radius (LR): Center-to-face dimension is 1.5× NPS (Nominal Pipe Size),
reducing pressure drop and erosion compared to Short Radius (SR) elbows.
- Used to change flow direction in piping systems while maintaining smooth fluid dynamics.
4. Applications
- Seawater desalination plants
- Offshore oil & gas pipelines
- Chemical and pharmaceutical processing equipment
- Flue gas desulfurization (FGD) systems
- Marine and coastal infrastructure
Why Choose 254 SMO (S31254)?
- For Critical Applications: Where failure due to corrosion is unacceptable (e.g., subsea pipelines, chemical reactors).
- Long-Term Reliability: Minimizes leaks, repairs, and system shutdowns.
- Compliance with Standards: Meets ASTM A403, ASME B16.9, and NACE MR0175 for sour service environments.
Chemical Composition max%
| UNS | C | Mn | P | S | Si | Cr | Ni | Mo | N | Cu |
| S31254 | 0.02 | 1 | 0.03 | 0.01 | 0.8 | 19.5-20.5 | 17.5-18.5 | 6.0-6.5 | 0.18-0.22 | 0.5-1 |
Mechanical Property
| Property | 254 SMO (S31254) | 316L | Duplex 2205 |
| PREN | >43 | ~25 | ~35 |
| Mo Content | 6% | 2–3% | 3–4% |
