CONTROL APPARATUS FOR A LIQUID FLOW, IN PARTICULAR FOR A RADIOACTIVE LIQUID

摘要

The device comprises at least one nozzle (T), in combination with a regulating valve (VR). A detector (135) measures the flowrate of the fluid in the nozzle and controls a distributor (109) for selecting a static pressure take-off orifice from among a plurality of regularly staged orifices in a convergent section (101). The orifice is brought into communication with a chamber (127) of the regulating valve to control the position of a closure member (119) which uncovers to a varying degree the orifices of a cage (117). The displacement of a distributor (121) from one position (R) to another (S) converts the regulating function into a shut-off function by pressure effect, by applying a high pressure to the chamber (127). The total immersion of the closure member obviates the disadvantages of the rod and packing system of conventional valves, as well as those resulting from the radiation-sensitivity of the prior art pneumatic servomechanisms.