Raised, conical seat prevents solids build-up from interfering with seal. Seat is hardfaced with Stellite to meet severe service. Alternative space age alloys are also used.

• 凸起的、锥形阀座避免实心颗粒淤积影响密封。阀座采用钨铬钴合金进行硬面处理，能够经受恶劣环境的考验。也可采用航空工业用合金制作的阀座。