Sour gas and produced-water service put sulfide stress cracking at the center of every material decision — hardness limits under NACE MR0175 often constrain material choice as much as corrosion resistance does.
| Dominant Failure Mode | Sulfide stress cracking (SSC) in H₂S-bearing service |
| Governing Standard | NACE MR0175 / ISO 15156 hardness and material limits |
| Typical Material Default | Duplex 2205, Alloy Steel, Inconel 625 for severe sour service |
| Typical Structural Type | Floating or Fixed, depending on ΔT and cleaning access |
Sour service constrains material selection before structural type is even considered.
It sets maximum hardness limits for materials in H₂S-containing service, since harder microstructures are more susceptible to sulfide stress cracking — this can restrict material and welding procedure choices beyond what corrosion resistance alone would suggest.
Not automatically — NACE compliance depends on the specific heat treatment condition and hardness achieved, which must be verified and documented, not assumed from the grade alone.
No — only H₂S-bearing (sour) service requires it. Sweet service (no significant H₂S) doesn't carry the same hardness restrictions, though buyers often specify NACE as a precaution.
Every enquiry is checked against governing code, material compatibility and manufacturing feasibility before a quote is issued. Use our product, material, grade and standards guides to freeze the RFQ — then confirm with engineering.
Send your fluid service, pressure class and governing standard — we'll confirm the right product and material.