Needle valve

with handwheelpneumatically-operatedelectric

The network has gained increasing importance trying to conciliate available water reserves and the always increasing request for water. Usually, the network capacity is always greater than the effective request; this implies the necessity to utilize devices able to control the distribution of the water without wasting it. Needle valve is especially designed to realize the function of regulating the water flow, maintaining an easy handling even in circumstances which comport heavy hydrostatic loads at its mouth and a very différent excercise pressure. The use of needle valve with the aid of actuators allows to utilize it in control systems with very différent functions. Water flow régulation actuated by needle valve is done by the horizontal sliding of an obturator, mechanically acted by an handle with a connecting rod-movement. Thanks to a spécial balanced chamber every kind of vibration or anomalous oleodynamic load are eliminated, moreover its internal shape is especially made to avoid the incurring of cavitation. The obturator moves in position to close the valve following the direction of the flow and allowing to control the change of the water flow without efforts. Either we regulate or stop a water flow in the concentration area, a réduction of the pressure occurs. When the pressure drops below the vapour saturation in the water, gases are generated with subséquent release of vapour bubbles in the zone of dépréssion. In this environment the bubbles, pushed by the flow, caused by the pressure différence downstream