Metal end-cap (MEC) seals replace traditional elastomeric FS seals in severe-service gate valves. Spring-energized Inconel jackets with graphite or PTFE inserts provide fire-safe, zero-leakage sealing even after elastomer destruction, meeting API 6A fire-test requirements and extending valve life in offshore and desert environments. https://globalsealstech.com/product-category/oil-gas-seals/api-6a-wellhead-equipment-seals/