Network friction loss
Three-tier hydraulic path — mainline + sub-main + lateral — summed to a total head requirement at the pump. Useful for sizing irrigation, manifold and pressurised-distribution pumps.
Mainline · Source → manifold
Head loss
1.31m H₂O
Pressure drop
0.129bar
Velocity
1.13m/s
Sub-main · Manifold → zone valve
Head loss
1.31m H₂O
Pressure drop
0.128bar
Velocity
1.27m/s
Lateral · Zone valve → emitters
Head loss
3.48m H₂O
Pressure drop
0.341bar
Velocity
1.63m/s
System pressure components
Total friction loss
6.1m H₂O
= 0.599 bar
Sum of all three tiers.
Static head
8m
= 26.2 ft
Outlet pressure (head)
20.4m
= 2 bar
Pump head required (TDH)
37.9m
= 34.5 m pre-margin·3.72 bar
Includes 10 % safety margin. Spec the pump curve at this head.