Metal cock ring soft seat surface pressure to the bearing surfaces, such as the valve core and valveseat is concentric ring surface can be a double tight closure.
金属旋塞表面压向阀座环软支座表面，如阀芯和阀座环表面是同心的，就能得到双重严密的关闭。
2
To employ double balanced valveseat design, it has smaller volume and larger displacement and can exert its advantages when needing large displacement.