Loss Coefficient for Fittings and Valves

Written by Jerry Ratzlaff on . Posted in Tables

 

ComponentLoss Coefficient \(K\)
Elbows  
90 Short Elbow, flanged  0.3
90 Short Elbow, threaded 1.5
90 Long Elbow, flanged 0.2
90 Long Elbow, threaded 0.7
45 Long Elbow, flanged 0.2
45 Short Elbow, threaded 0.4
   
180 Return  
180 Return, flanged 0.2
180 Return, threaded 1.5
   
Tees  
Line flow, flanged 0.2
Line flow, threaded 0.9
Branch flow, flanged 1.0
Branch flow, threaded 2.0
   
Union, threaded 0.08
   
Valves  
Diaphragm, fully open 2.3
Diaphragm, 1/4 closed 21
Diaphragm, 1/2 closed 4.3
Globe, fully open 10
Angle, fully open 2
Gate, fully open 0.15
Gate, 1/4 closed 0.26
Gate, 1/2 closed 2.1
Gate, 3/4 closed 17
Swing Check, forward flow 2
Swing Check, backward flow  \(\infty\)
Ball, fully open 0.05
Ball, 1/3 closed 5.5
Ball, 2/3 closed 210
Water meter 7

 

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Tags: Equations for Velocity Equations for Coefficient Equations for Friction