Method for water hammerless opening of fluid passage, and method for supplying chemical solutions and device for water hammerless opening for which the method is used

A device for water hammerless opening of a fluid passage, comprising:

• (a) an actuator operating type valve installed on a fluid passage in a state of having a constant fluid pressure;
• (b) an electro-pneumatic conversion device equipped with a memory storage for storing a control signal Sc from a tuning box and disposed to supply a 2-step actuator operating pressure Pa to the actuator operating type valve;
• (c) a vibration sensor operable to detect vibration in the fluid passage caused by flow of fluid in the fluid passage, and the vibration sensor is removably fixed to the fluid passage on an upstream side of the actuator operating type valve;
• and
• (d) a tuning box disposed to receive as input a vibration detecting signal Pr detected through the vibration sensor and to output to the electro-pneumatic conversion device the control signal Sc to control a step operating pressure Ps′ and a step retention time t of the 2-step actuator operating pressure Pa, wherein the tuning box uses the vibration detecting signal Pr to adjust the control signal Sc so that output from the electro-pneumatic conversion device of the 2-step actuator operating pressure Pa comprising the step operating pressure Ps′ makes the vibration detecting signal Pr nearly zero so that the actuator operating type valve opens the fluid passage without causing a water hammer in the fluid passage when the 2-step operating pressure Pa is supplied to the actuator operating type valve.