What is Head Pressure and How Is It Calculated?
Author: Terry Newhaven
Head pressure is the force that a pond pump must overcome to push water out of the end of a tubing run....like to a waterfall. To calculate head pressure you must take into account vertical lift resistance, length of pip/ hose and fittings.
Vertical Lift = 1' head pressure
10' of Hose = 1' head pressure
90° Fitting = 2' head pressure
Other Fittings = 1' head pressure
The basic formula for calculating head pressure is:
Vertical Lift + (Length of Tubing/ 10) + (90° Fittings*2) + Other Fittings = Total Head
Example: If your waterfall is 5' high and you have one 90° fitting, 20' of tubing and 2 other fittings, how much head pressure is that?
5 + (20/10) + (1*2) + 2 = 11' total head pressure.
This means when you are looking at the flow charts on the pond pumps, you need to look at the flow rate at 11' of head pressure to determine the appropriate sized pump for your application.