Losses due to elevation
Pressure can be designated in many units from bar (si), psi (imperial) or also in high
of a water column (feet or metres). In imperial units the weight of one foot of water
is equal to .4328 psi. In other words for every foot of elevation change from the
discharge of the pump to the point of discharge of the hose there is a pressure of
.4328 psi applied to the pump.
1 foot of water (head) = .4328 psi