Pressure loss in pipes is determined by  friction, vertical pipe difference or elevation, changes of kinetic energy. To calculate pressure loss  in straight pipes or piping components following formulas are used.

Pressure loss in straight tubes

Δp = λ(10r l v2 / 2d) (bar) 

λlam = 64 /Re      

λturb = 0.316 / 4 Re1/2

Re= (vd / ν)103

V = (Q / 6(πd2 / 4))102  (m/s)


 λ = friction inside tube 

v = flow speed (m/s) 

n = Kinematic viscosity(cSt or mm2/s) 

Q = flow (l / min)



Pressure loss in piping components

ploss= ξ / 2ρv2hloss= ξ v2 / 2g ξ= loss coefficient ploss= pressure loss hloss= head loss

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