Design patent number: [992 32817.9] Design and production standard: 1). Flange coupling dimension: GB9113.1-9113.26-1998 2). Valve structure length: GB12221-1989 3). Valve test standard: GB/T13927-1992 4). Seal test pressure: 1.1PN 5). Intensity test pressure: 1.5PN Main technical parameters: 1). Working pressure: 1.0MPa, 1.6MPa, 2.5MPa, 4.0MPa. 2). Operating pressure: No less than 0.5MPa 3). Applicable medium: Primary water, rinsing, oil, sewage and seawater 4). Slow opening time: 0~120S (adjustable) 5). Slow closing time: 3~60S (adjustable) 6). Pressure loss: <0.03MPa (when speed is 2m/s) 7). Peak value of water hammer: <1.5 times of working pressure 8). Main structure type: Piston type 9). Loss coefficient: 1.5~2.5 10). Leakage volume: No visual leakage