Sour-service API 6A wellhead equipment seals Singapore comply with NACE MR0175/ISO 15156 to resist sulfide stress cracking in H2S-rich reservoirs. Specialized FKM and HNBR grades offer low swell and high hardness. Singapore procurement for Southeast Asia sour fields demands fully documented materials from trusted suppliers for reliable barrier performance https://globalsealstech.com/product-category/oil-gas-seals/api-6a-wellhead-equipment-seals/