Major loss in long pipes is due to friction, Mainly given by Darcy weisbach equation hf=
fLV2
2gD
f → Friction coefficient L → Length of pipe V → Velocity of flow g → Gravitational acceleration = 9.81 m/sec2 D → Diameter of pipe Minor losses in pipe:- → Losses due to sudden expansion he=
(V1−V2)2
2g
→ Losses due to sudden contraction he=
V22
2g
(
1
Cc
−1)2 he=0.5
V22
2g
Cc= Coefficient of contraction Cc=
V2
Vc
→ Losses at exit of pipe he=
V2
2g
→ Losses at entrance of pipe he=
0.5V2
2g
→ Losses due to bends he=
KV2
2g
K = Bend coefficient ≈ 1.2 for 90° bend ≈ 0.4 for 45° bend.