Low-pressure setup (< 0.5 bar / < 7 psi)
Low-pressure setups operate without a conventional pressurized water supply, such as a garden tap. Instead, the required pressure is generated by the height difference between the water source and the irrigation outlets.
A typical low-pressure setup consists of an elevated water container, such as a rain barrel or storage tank, connected to OpenValve with a hose. From OpenValve, a main irrigation line distributes the water to the plants, often branching into smaller tubes and emitters. The water flow in this system is therefore created solely by the height difference between the water level in the container and the irrigation outlets.
This type of setup can be useful on balconies, in community gardens, in off-grid locations, or in gardens that rely on collected rainwater. It allows OpenValve to operate without a permanent pressurized water connection and can make irrigation systems more independent and resource-efficient.
The available pressure in a gravity-fed system is determined by hydrostatic pressure: the greater the height difference between the water level in the container and the irrigation outlets, the higher the pressure available for irrigation.
As a rule of thumb:
1 meter of height difference ≈ 0.1 bar
This means that the water source must be positioned sufficiently above the irrigation outlets to provide enough pressure for reliable operation.
Because the available pressure is relatively low, gravity-fed systems require more careful planning than pressurized setups. Factors such as the elevation of the water container, hose diameter, hose routing, trapped air in the lines, and emitter selection have a much greater influence on the resulting water flow and overall system performance than they do in pressurized systems.