Quality Standard For Steel Castings For Valves

SP-55 details the visual inspection criteria for castings. This specification is listed as part of the procedure under API 598. NACE MR-0175 Standard Material Requirements for Sulfide Stress Cracking Resistant Metallic Materials For Oilfield Equipment MR-0175 is the "standard" for materials used in "sour" environments such as found in piping systems in many refineries. It lists materials, mechanical properties and heat treatments for metals used in Hydrogen Sulfide bearing hydrocarbon service.