A Water Hammer Protection Method for Mine Drainage System Based on Velocity Adjustment of Hydraulic Control Valve

Table 2

Times of equipment in multistage valve-closing.

Equipment actions	Pump start	Valve-opening	Full open	Valve-closing	Valve closed	Water hammer finished	Total times
Times (s)	4.128	8.5	39.504	46.007	89.830	128.816	43.823