The invention discloses a butterfly
centrifugal pump self-control valve and a control method, and aims to solve the problem that an existing water pump control valve fails due to blockage of liquid impurities in a
pipe network. The self-control valve comprises a valve body, a butterfly plate, a valve rod, a
hydraulic cylinder and the like, the
hydraulic cylinder comprises a
piston cylinder, a
piston and a cylinder seat with a quick / adjusting channel, and the adjusting channel is matched with an adjusting screw;
purified water or oil is adopted as an independent hydraulic driving medium, and
impurity blockage is avoided. When the valve is opened,
water pressure of the water pump pushes the butterfly plate to rotate, and the
piston firstly cuts off the quick channel to realize light-load pump starting and then communicates with the channel to fully open the butterfly plate; when the valve is closed,
backflow water and
gravitational torque of the butterfly plate drive the piston to move downwards, a rapid channel is
cut off in the later period to reduce water hammers, and
backflow is prevented after full closing. The device is simple in structure, low in cost, high in reliability, adaptive to an outlet of the
centrifugal pump and capable of avoiding pump starting
tripping and
water hammer accidents.