Subsea wellhead connector seals (VX/VT gaskets) use large metal end-cap or spring-energized designs. They seal 20,000 psi on 18-3/4" mandrels and survive multiple make/break cycles during drilling and completion without damage or leakage. https://globalsealstech.com/product-category/oil-gas-seals/api-6a-wellhead-equipment-seals/