Shree Impex Steel supplies buttweld pipe fittings compliant with NACE MR0175 / ISO 15156 for sour service H₂S environments. Hardness certified, MTC with NACE compliance statement. WPB carbon steel, SS 316L, Duplex S31803. Oil & gas sour service. Mumbai India.
NACE MR0175 / ISO 15156 is the standard governing material selection for equipment used in H₂S-containing oil and gas environments. H₂S causes Sulfide Stress Cracking (SSC) in susceptible materials — NACE compliance ensures the fitting will not fail in sour service.
The primary NACE requirement for carbon and alloy steel fittings is maximum hardness of 22 HRC (250 HBW). Higher hardness materials are susceptible to SSC. We test and certify hardness on every NACE batch.
NACE compliance requires proper heat treatment — normalized and tempered for carbon steel, solution annealed for stainless. Our annealing furnace ensures correct heat treatment for all NACE grades.
NACE supply includes EN 10204 3.1 MTC with NACE MR0175 compliance statement, hardness test results per fitting or per heat, heat treatment certificate, and chemical composition confirming NACE limits.
For critical sour service projects requiring witnessed hardness testing — SGS, Bureau Veritas, and TÜV third-party inspection can be arranged. EN 10204 3.2 with NACE compliance available on request.
| Grade | NACE Requirement | Key Limit | We Supply |
|---|---|---|---|
| WPB Carbon Steel | Hardness ≤22 HRC | Max 250 HBW | ✓ Yes |
| WP11 / WP22 | Hardness ≤22 HRC + PWHT | PWHT mandatory | ✓ Yes |
| LTCS WPL6 | Hardness ≤22 HRC | Impact tested | ✓ Yes |
| SS 304 / 316L | Solution annealed | No hardness limit | ✓ Yes |
| Duplex S31803 | Solution annealed | Ferrite content controlled | ✓ Yes |
| Inconel 625 | Solution annealed | Generally acceptable | ✓ Yes |
Grade, type, size, schedule, quantity. We respond within 4 hours.