A packing assembly 9 is arranged between the valve stem 3 and the valve cover 2, the O-ring 10 is further arranged on the upper part of the packing assembly 9, the upper part of the O-ring 10 is provided with a packing gland 11, the valve body 1 is provided with an arc-shaped end face 12, the arc-shaped end face 12 forms a line seal between the valve body 1 and the valve seat 7, and the contact end of the valve disc 4 and the valve seat 7 is provided with a water grain surface 41. The arcuate end face 12 forms a line seal between the sealing surface of the valve body 1 and the valve seat 7. The water grain 41 can ensure the sealing performance of the valve seat 7 and the valve disc 4.Observer1 has received!Netflix已续订《我本坚强》第三季。然大敌当前，故从轻发落：令革去火长之职，并重责一百军棍，以儆效尤。…………光阴长河，川流不息。ChannelId Nick Hornby继续负责剧本，Stephen Frears回归担任导演。Brendan Gleeson、Patricia Clarkson和Esco Jouléy主演。
