| 摘要 |
PURPOSE:To permit the seal through metal contact between a housing and a seat retainer even if the sealing performance of a combustible seat ring is eliminated by a fire, etc. CONSTITUTION:An annular groove 11 whose inside wall surface is formed into an inclined surface 10 so that the width is reduced towards the bottom part is formed onto the outer peripheral surface of a seat retainer 4 between a valve seat 6 and a seat ring 8. A seal ring 13 having incombustibility whose free edge is cut to provide a stepped surface 12 extending in the longitudinal direction is fitted into the annular groove 11, and said ring 13 is heated from the back-surface side, and the front surface 14 is brought into face contact, and the upper surface 15 is brought into face contact with the inner wall surface of a housing. |
