Flange sealing in API 6A wellheads utilizes metal ring gaskets positioned in grooves machined into flange faces. Proper groove dimensions ensure correct gasket compression when bolts are torqued to specification. Flange surface finishes, typically 63 to 125 microinch Ra, are controlled to ensure effective sealing without gasket damage. Bolt torque sequences and values follow API speci... https://globalsealstech.com/product-category/oil-gas-seals/api-6a-wellhead-equipment-seals/