A system for separating water from crude oil, a bulk storage tank for storing crude oil (101), a first pipe for sending the water separated from the crude bulk storage tank to the receiving system (105) (104) and a second pipe to be sent to the shipping of crude oil system (107) (106), a first valve for controlling the flow of the first pipe (104) (102), the second pipe (106) of the It comprises a second valve controlling the flow (103), and a control system for controlling the operation of the first valve and the second valve (104, 106) (151). The control system includes a control device that controls the first valve and the second valve, the acoustic sensor of water attached to the first pipe in order to sense the sound pressure level while flowing through the first pipe an array (109), the sound pressure level sensed, and means for comparing the predetermined sound pressure threshold level that characterizes the flow of the mixture of oil and water flowing through the pipe, the measured sound pressure level is the sound pressure threshold upon reaching the level, and a control device for opening the second valve closes the first valve. Another measurement means in the form of a conductivity sensor (108) may be a.
.FIELD 1