How to diagnose problems in a drip irrigation system

After taking the basic readings of the drip irrigation system, it will be necessary to carry out monitoring, constant over the time, of the operating parameters identified in order to identify and resolve any operating problems.

Monitoring the system’s current operating pressure and flow rate values and comparing them with the basic reference readings recorded after the initial start-up of the system makes it possible to ascertain that the system is functioning over time.

Important variations of these values from reference readings may indicate:

1. Incorrect control equipment settings or control equipment failure;
2. Clogging of filters or dispensing devices by inorganic, organic or mineral precipitates;
3. Leakage from faulty pipes or hoses, loose connections, rodent or insect damage.

The flow rate values

First of all it will be necessary to compare the recorded pressure values at the pump outlet with the recorded flow rate values of the system. In case of significant deviations, the following situations may occur:

1. High pump outlet pressure and high system flow: indicates that the pump valve is too open and a reduction is required;
2. Low pump outlet pressure and low system flow rate: indicates that the pump valve must be more open;
3. Low pump outlet pressure and high system flow rate: may indicate that a valve has been opened incorrectly or that there is a leak in the system;
4. High pump outlet pressure and low system flow rate: may indicate an occlusion of dispensers or filters or an incorrect opening of one or more valves.

Compared values between pressure and flow rate

The comparison between the filter outlet pressure and the recorded flow rate value of the system allows to verify, in case of significant deviation with the reference readings, one of the following problems:

1. High pressure outgoing filter and high flow rate of the system: indicates that the pump valve is too open and a reduction is required;
2. Low pressure outgoing filter and low flow rate of the system: may indicate filter occlusion or that the pump valve should be more open;
3. Low pressure outgoing filter and high flow rate of the system: may indicate that there is a leak in the system or that a system valve has been incorrectly opened.
4. High pressure outgoing filter and low flow rate of the system: may indicate an occlusion of the dispensers, the need to open one or more valves more or to open one of the valves of the irrigation system that is still closed.

The last comparison to be made is between the outgoing and ingoing pressure in the sector valve and the recorded value of the system flow rate. If there are significant deviations with the reference readings, one of the following situations may occur:

1. High pressure outgoing sector valve o and high flow rate of the system: may indicate that the sector valve is too open or that the opening of the valve of the pump must be reduced.
2. Low pressure outgoing sector valve and low flow rate of the system: may indicate that the sector valve must be more open or that the valve of the pump must be more open or that the filters are occluded and must be cleaned.
3. Low pressure outgoing sector valve and high flow rate of the system: may indicate that the sector valve is incorrectly opened or that there is a leak in the system.
4. High pressure outgoing sector valve and low flow rate of the system: may indicate that the nozzles are occluded or that a sector valve needs more opening.

Monitoring the pressure and flow rate values over time and comparing them with the recorded values of the basic reference readings therefore allows a wide range of drip irrigation system operational problems to be identified and resolved.