Resistance, which a fluid subject to friction must overcome when flowing through and valves. It is noticeable in the form of a pressure drop (pressure loss).
The flow resistance comprises frictional losses and the form-related losses (Figure D 91).
Previous expression:
![cf53c2db8d129d2bd13ae68d8e7ae4d5a6e54a79 0001_durchflusswiderstand.gif](/fileadmin/smc/files/cf53c2db8d129d2bd13ae68d8e7ae4d5a6e54a79.gif)
Figure D 91: Flow resistance caused by frictional losses (πρ) and form-related losses (pF)