Throttle is the general term used for a physical flow resistance. Throttle is therefore the generic term for orifice and nozzle. Flow resistances with a largely linear dependence of the flow rate on the pressure difference (capillary tube) (Figure D 43) are often termed laminar throttles. Hydraulic resistances that occur in practice are often a mixture of an orifice, nozzle and laminar flow resistance (Figure D 44), i.e. apart from the pressure difference, the flow rate is also dependent to some extent on the viscosity of the pressure fluid.
![d4291d5b38e6301954d3d60b045b5276e76ffa15 0001_drossel.gif](/fileadmin/smc/files/d4291d5b38e6301954d3d60b045b5276e76ffa15.gif)
Figure D 43: Laminar throttle
![04750b297e69a6ddb173615f12182aa252e94c26 0002_drossel.gif](/fileadmin/smc/files/04750b297e69a6ddb173615f12182aa252e94c26.gif)
Figure D 44: Common throttle forms