Pressure ratings in API 6A wellhead seals follow standardized working pressure designations of 2,000, 3,000, 5,000, 10,000, 15,000, and 20,000 psi. Each rating requires specific seal designs, materials, and anti-extrusion features to contain the rated pressure with appropriate safety factors, ensuring seals do not fail through extrusion, blowout, or material degradation. https://globalsealstech.com/product-category/oil-gas-seals/api-6a-wellhead-equipment-seals/