To provide a pinch valve which prevents any excessive tightening when the valve is fully closed and any mistaken operation caused by any mistakes of a worker, and keeps the constant flow rate even when any disturbance is present on a pipe line.
The pinch valve comprises: a body 5 with an elastic tubular body 4 accommodated in a lower part thereof and a bonnet 2 fitted to an upper part thereof; a handle 1 which is inserted in the bonnet in a turnable and vertically fixed manner; a holder body 3 which has a stopper ring 18 abutting the handle 1 fixed to an upper end thereof, and has a holder 22 which is vertically moved by the turn of the handle to press a tubular body on a lower end; and connection parts 6 provided on both sides of the body to connect the tubular body to other tube. A lock nut 31 to lock the rotation of the handle is screwed to an outer circumferential surface of the handle. The stopper ring 18 prevents the valve from being excessively tightened, and the fully-opened condition, the intermediately-opened condition, and the fully-closed condition are fixed by adjusting the rotation of the lock nut 31.
|WO/1985/002240||A DEVICE FOR REGULATING THE FLOW AREA IN A FLEXIBLE TUBE|