# Why is the head loss in submerged pipe is 0

Looking at this question :

Point C head loss is 0 according to the author Bottom right Can’t understand why , any good explanation for this claim ?

Look at page 33 at the top

• The only way for that to happen is : 0 velocity at the top submerged pipe zero pressure At the top submerged pipe Apr 16 at 10:05
• are you sure they mean the area of the outlet of pipe ( C' ) or maybe it's about the reservoir ( C )in general?
– SF.
Apr 16 at 11:46
• C in general because C’ is for another question relating to sudden cut of the pipe Apr 17 at 8:08

The symbol $$H_{\mathsf{C}}$$ here doesn't represent a head loss, it represents an "absolute" head at point $$\mathsf{C}$$. Assuming that the fluid velocity in the region vertically above $$\mathsf{C}$$ is negligible, so that the pressure variation in that region is hydrostatic, that absolute head is equal to the vertical co-ordinate of the free surface above $$\mathsf{C}$$. The origin of co-ordinates is defined to be on that free surface, so the absolute head at $$\mathsf{C}$$ is zero.