We are often asked if gravity feed will work with a drip irrigation system. The answer is yes, but there are limitations. Gravity feed systems often operate at very low pressures but all drip irrigation systems require minimum pressure.
How much pressure is needed? Most drippers and dripline require 10 PSI, and 15 to 30 PSI is best. Pressure compensating drippers such as the D4, D5 or D45 need a minimum of 10 PSI to open due to a valve inside the dripper that prevents drainback at shutdown.
Very low pressure
Can you operate a drip system with less than 10 PSI? Yes, but be sure to use non-pressure compensating drippers such as the D1, D2 or D3 or non-pressure compensating dripline such as the DL4100 or DL6200.
The lower the pressure, the greater the effect of friction losses in the tubing that will slow the flow of water. If the pressure is too low, the drippers at the end of the circuit may not flow at all.
Click here to see a graph showing rate of flow at low pressure for our DL4100 dripline.
Drippers rely on high turbulence in the water to keep silt and fine organic material suspended in the water long enough to flush out. Low pressure results in low turbulence. Silt in the water may settle and clog the small openings in drippers over time.
Choose non-pressure compensating drippers such as the D2 for low pressure drip systems
Non-pressure compensating dripline such as the DL4100 will also work in low-pressure gravity feed drip systems
DL6200 Thinwall Dripline is suitable for low-pressure drip systems
This is the adapter you need to tap into the bottom of a water barrel. It's a FA27