ue89e dq ue89e ue89e max 1 2 u00b7 kvs u00b7 dp 1 2 u00b7 ddp dp 1 2 u00b7 dkvs ue89e dq ue89e ue89e max 0 gt ue89e 1 2 u00b7 kvs u00b7 dp 1 2 u00b7 ddp dp 1 2 u00b7 dkvs the dynamic flow regulating body 3 which will be further described in fig2 and 3 has the characteristic feature that an increasing pressure difference on the body 3 will actuate same for compression of a spring actuated slidable part containing one or more restriction areas which are limited by being cut off by the fixed part whereby the kvs value varies in response to the pressure difference the result thereof is that the flow remains constant within a regulating range given by the spring the essential feature of the present invention is therefore a dynamic flow regulating body 3 which is substantially known and used for the sole purpose of limiting the flow in a system with a flowing medium and is moreover used for regulating the flow under the authority of an electric actuator and or a thermostatic constituent as further shown in fig1 a 1c the valve unit 2 comprises an insert housing 19 wherein parallel to the axis thereof a second housing 11 is mounted in the center upper part of the second housing 11 there is mounted a valve cone 10 made of an elastomeric material extending from the valve cone 10 in an upward direction is a spindle piston rod 17 which is connected at its other end to an activation means 13 by means of the activation means 13 the valve cone 10 may take an arbitrary axial position between normal non activated open position and an activated closed position the second.