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Orifices for speed control
![Symbol orifices](https://sp-ao.shortpixel.ai/client/to_auto,q_glossy,ret_img,w_194,h_76/https://learnchannel-tv.com/wp-content/uploads/2017/03/Symbol-orifices.png)
Symbol orifices
In contrast to the throttle, the ratio of length L compared to flow diameter d is small.
Guide value: L / d <1.5
![Flow Trough Orifice](https://sp-ao.shortpixel.ai/client/to_auto,q_glossy,ret_img,w_423,h_126/https://learnchannel-tv.com/wp-content/uploads/2022/04/Hydraulics-Orifice-function.png)
Hydraulics - Orifice function
Advantage of the orifice is that the viscous fluid friction is very low and thus the flow rate hardly depends on the viscosity. Disadvantage are the swirls especially at the exit point of the aperture.
![Hydraulics - orifice - function and circuit example](https://sp-ao.shortpixel.ai/client/to_auto,q_glossy,ret_img,w_455,h_216/https://learnchannel-tv.com/wp-content/uploads/2022/04/Hydraulics-orifice-function-and-circuit-example.png)
Hydraulics - orifice - function and circuit example