Chief structural features and usage
1. The main body of this series of valve uses a casting and forging structure and has a dual-direction seal of parallel second semi-forced dual-sealing, and the separate working of both sealing face motion and tapered block to wedge up have the zero leakage come true.
2. The sealing face is of a small frictional force of motion, lightly opened & closed and has a self-compensation function for wearing.
3. Simple and compact structure, easy to overhaul, long to more than 10 years of duration
4. Filling chamber of bonnet has vacuum sealing structure with self-expanding and impacting, completely isolating system from air and have very good property of system sealing.
5. Two connection ways of flange and welding, two driving modes of manual and electrical actuated.

The valve can be used as open & close device for the pipeline under the working temperature of 425?C and 550?C and the working medium of water, steam or air; especially suitable to act as the vacuum isolating sealing for the system of the steam turbines condensation and vacuum negative pressure in steam power station.