Common Irrigation Pump Related Issues

Irrigation pumps are used these days in almost all agricultural operations for the pumping of water from a lower level to a higher one or raising the pressure of water for the purpose of sprinkling it on the field.  Pumps can be referred to as the nucleus of irrigation systems we see around us. For sprinkling water in our lawn using a garden hose, the standard municipal water pressure is generally good enough. However, a much higher pressure is required for irrigation systems to operate in a seamless manner. Pumps used in irrigation generally include propeller, submersible, deep-well turbine, and centrifugal pumps. Interestingly, the first three types of pumps are also centrifugal pumps in special forms. During the selection of an irrigation pump, one must ensure the availability of source of water, required pumping flow rate, total suction head, and total dynamic head.   Causes of Irrigation Pump Problems: Typical problems with pumping systems fall under the categories as discussed below. Cavitation: In simple words, cavitation refers to the formation of bubbles in a fluid. This may happen whenever the local pressure falls below a particular fluid’s vapour pressure at any given temperature. Cavitation leads to pitting within the pump’s impeller, casing, and volutes, resulting in weakening of the metal and significant increase in resistance to flow. As a result, the pumping efficiency of the system is decreased. Cavitation can also decrease the service life of pumping systems by introducing shock loads to the motor as well as shaft. Wear and Tear: Many different types of particulate matters are present in groundwater and some of them can have a negative impact on pumping system operations. Regardless of their concentration or size, these particulate matters tend to roughen the pump’s interior surface by scouring them. Over a period of time, this reduces the pumping system’s efficiency and eventually the system may fail to produce sufficient lift for supplying water to crops. Fouling: This problem takes place most commonly in the distribution lines that connect to the outflow or intake of a pump. A pump itself may also experience fouling when an extremely fine particulate matter gets stuck on the internal surface of a pump or a coarse particulate matter gets ingested by the pump but can’t be expelled. The efficiency of a pump reduces to great extent because of fouling and the pump may eventually fail completely.   Motor Issues: Some common issues related to the motor include

• Damage to the insulation because of overheating of the motor.
• Insulation may also be damaged when water gets inside the housing of the motor.
• The rotor of the pump may come into direct contact with the surface of the stator, causing a catastrophic failure of the pump or motor.

Water Level: Water is drawn continuously into an irrigation system as long as the level of groundwater is above the pumps intake point. However, there can be a marginal fall in the local water level, once the pump starts operating. This drawdown effect can sometimes result in air getting sucked in by the pump because of a water level that is below the intake of the pump. If you are facing any of these issues with your irrigation pumping system, please get in touch with our experts right away. At Agri-Flo Rural, we specialise in delivering cost-efficient solutions to your irrigation equipment related problems.