This valve is opened by means of a cylinder driven by the hydraulic power pack. The
valve is only set to open at a constant speed, and the opening time can be adjusted by adjusting the knob of the valve opening in the hydraulic oil station. Before the 75 ° fast closing, time is 5 ~ 12 seconds (adjustable site); after the 15° slow closing, time is 20 ~ 40 seconds (adjustable site). The realization of closing the valve fast and slow is mainly regulated by controlling the amount of oil drainage through adjusting the two-way oil drainage regulating device. The regulating part is in the part protruding from the upper part of the oil cylinder. If the adjustment is needed, the part protruding from the upper part of the oil cylinder should be removed.