NACE MR0175 Valves Guide
NACE MR0175 / ISO 15156 addresses materials for H2S-containing oil and gas production environments, but compliance depends on material condition, hardness and the specific environmental limits.
A valve described as suitable for sour service still requires control of pressure-boundary material, trim, bolting, welding, hardness and any project-specific restrictions.
Provide H2S partial pressure, chloride, pH, temperature, material requirements and the purchaser’s sour-service specification when requesting a NACE-related valve.