Valve body materials use casting designations: WCB (ASTM A216 Carbon Steel, max temp 425°C), WC6 (1.25Cr-0.5Mo, to 540°C), WC9 (2.25Cr-1Mo, to 570°C), C5 (5Cr-0.5Mo). Stainless steel: CF8 (304 SS), CF8M (316 SS), CF3 (304L), CF3M (316L), CN7M (Alloy 20). Forging designations: A105 (carbon steel), F22 (2.25Cr-1Mo), F91 (9Cr-1Mo-V). Trim materials use AISI designations: 304, 316, 410 (13Chrome), 440C (for seats). Example: Gate valve with WCB body and 316 trim means carbon steel body with stainless steel disc and stem. For Saudi Arabian sour service, verify H2S content and select NACE-compliant materials per MR0175.