Ball and seat sealing design: Soft-seal ball valves achieve zero leakage through elastic deformation of the valve seat, but their temperature resistance is limited (typically ≤200℃); hard-seal ball valves achieve a metal-to-metal seal, withstanding temperatures up to 600℃, but require high-precision machining to ensure a tight seal.
Stem anti-leakage structure: A top-entry stem design, combined with double seals (such as O-rings + packing), effectively prevents media leakage along the stem. Some high-end ball valves are also equipped with explosion-proof devices to ensure safe operation under extreme conditions.
Fire safety design: In flammable and explosive environments such as petroleum and chemical plants, ball valves must meet API 607 or ISO 10497 fire safety standards. Their structure typically uses a metal-to-metal seal, with a fire-resistant ring between the valve seat and the ball. Even if the soft seal material burns out, media leakage can still be prevented through the metal seal.
