| 摘要 |
PURPOSE:To prevent a valve and a valve seat from adhering to each other by providing a valve seat which can be separated into a valve seat element and a valve seat stator, and fixing the valve seat to a valve body through a packing to change the diameter of the valve seat. CONSTITUTION:A projecting flange 17 of a valve seat element 16 where a hard positive pole oxide film and a composite hard film made of fluoric resin are formed is fixed to a valve body 19 through a packing 20 by a valve seat stator 18. Thus, the valve seat element 16 can be separated from the valve seat stator 18, so that in case of changing the diameter of the valve seat, only a simple valve seat element 16 may be provided. Since a composite hard film is applied only to the valve seat element 16, the cost is reduced. The valve and valve seat are prevented from adhering to each other on the valve seat side, so that the surface of the rubber valve is smoothed not to deteriorate the stopping function. |
