The needle valve is mainly designed for water flow regulation in a pipeline. The flow regulation is achieved by the axial movement of a piston, which is operated by a rod and crank mechanism.
The piston reduces the flow by closing in the flow direction, and operates in a housing with equalized pressure; this allows the valve to operate in a stable and smooth manner, without vibrations and with a low operating torque. The regulation is achieved with high head losses, when the valve is less than 40% open, and very low head losses, when the valve is more than 50% open.
YES: for shut-off operation and for discharge to the atmosphere with high pressure differentials. The valves are suitable for all kinds of water plants. Available for pressures up to 64 bar. All sizes (DN) are supplied with a gearbox.
If necessary (because of the operating conditions), the shutter can be equipped with a stainless steel slotted cylinder (anti cavitation device), which allows modulation of the energy dissipation, thereby achieving greater resistance to cavitation, and modification of the regulating curve of the valve to meet the requirements of the plant.