Technical features: 1). Easy working of discs: When valve opening or closing, valve core will connect or disconnect seal face instantly with no rotary friction, low operating moment for time and energy saving; 2). Structure compacting: Shorter length than plug valve or ball valve, and its height is just 1/3 of rising stem gate valve with small volume and light weight; 3). Reliable seal: Seal face is structure of bilateral symmetry with two way sealing and uniformly stress; When sealing material of valve core is rubber, two way sealing with zero leakage can be guaranteed; 4). Low resistance: Valve body is adopted design of straightway type full channels, and excess flow area of valve core is a little larger than which of valve body for low resistance, so resistance coefficient of valve is equal with which of similar length piping, and relative loss of hydraulic head is zero; 5). Long service life: Seal face of valve core is adopted construction of inverted circular cone. If seal face is worn, valve core will move downwards automatically to compensate for keeping well connection of seal face which can prolong service life; 6). Convenience maintenance: Valve body can be separated from other components, so valve can not be disassembled from piping for online maintenance; 7). Well regulation: Flow curve for valve opening is flat, flux regulation is convenience and precise. Main technical parameters: 1). Nominal bore: DN50~1000mm; 2). Nominal pressure: PN0.6~25MPa; 3). Drive type: Hydraulic, electro hydraulic, electric, pneumatic and manual; 4). Applicable medium: Rinsing, original water, seawater, sewage, oil product, coal gas, nature gas, liquefied gas and steam; 5). Applicable temperature: Rubber seal -40C~120C; 6). Applicable environment: Condition of flammable, detonable, volatilizable or virulent.