The evolution and function of ball valve

Ball valve is evoled from plug valve.It has same 90 degrees ratation and the same rotating parts that are often in contact with the seal seat.The plunger is spherical.It has circular through-holes or channels through its axis.The ratio of the sphere to the opening should look like this:when the ball ratates by 90 degrees,the inlet and outlet should all appear spherical,thus cutting off the flow.Ball valve require only 90 degrees rotation and a small torque to close tightly.Completely parallel to the valve body cavity for the medium provides little resistance,through the flow path.Even with shrinkage cavity,the pressure drop produced by the medium passing through the valve is still small.Therefore,from an economic point of view,most of today’s ball valves have been used to shrink mouth.But the valves needed to clean the line with ‘tube cleaner’ are the most common exception.It is generally considered that ball valves are most suitable for opening and closing directly,but recent developments have designed them for throttling and flow control.