Wellheads in sour service environments containing hydrogen sulfide require specialized seal materials resistant to sulfide stress cracking, explosive decompression, and chemical degradation. HNBR and FFKM compounds provide enhanced H2S resistance compared to standard nitrile or fluorocarbon materials. Explosive decompression testing per NACE TM0187 evaluates seal integrity when rapid ... https://globalsealstech.com/product-category/oil-gas-seals/api-6a-wellhead-equipment-seals/