Q-H curve

The pump performance curve shows the relation between flow and head.

The pump performance curve is shown in the figure, where Q (flow) is the X-axis and H (head) is the Y-axis. 

The units for Q are normally [m3/h] or [l/s]
The unit for H is normally [m]
 
H (head) can be recalculated to p (pressure) by using the following equation:
 
p = ρ x g x H [pa]
p = pressure [pa]
ρ = density [kg/m3]
g = acceleration due to gravity [m/s2]
H = head [m]