NACE MR0175 Compliance: Understanding the Minimum and Maximum Partial Pressure of H₂S

If you’re in the oil and gas production industry, you’re likely familiar with NACE MR0175, an international standard for metallic materials. But do you know the minimum and maximum partial pressure of H₂S required for compliance? Let’s explore.

The Sour Service H₂S Partial Pressure Cut-Off Value

One question that often arises is the sour service H₂S partial pressure cut-off value. While this value isn’t sharp and accurate, a practical engineering value of 0.3 kPa is typically used. It’s important to note that steel used in these environments should be resistant below 0.05 psi (0.3 kPa).

Corrosion-Resistant Alloys (CRAs)

It’s worth noting that there are no ppH₂S limits for corrosion-resistant alloys (CRAs). This is because precautions need to be taken whenever the possibility of H₂S is present.

Additional Resources

For more information on NACE MR0175 compliance, check out our video on the lower limit of ppH₂S and our frequently asked questions page. This question pertains to NACE MR0175/ISO 15156-2 Clause 7.1.2. Reference: ISO 15156 Maintenance Panel Inquiry #2009-18.