A jet pump is a type of fluid-handling device that uses a high-velocity liquid or gas stream to create a pressure difference and move another fluid without any moving mechanical parts inside the pumping chamber. It is widely used in industries, water systems, and specialized process applications because of its simple structure, strong reliability, and ability to operate in environments where conventional pumps may face limitations.The working principle of a jet pump is based on the Venturi effect and momentum transfer. A motive fluid enters the nozzle at high pressure and is accelerated into a narrow jet. As the fluid velocity increases, the pressure drops, creating a low-pressure zone that draws in the secondary fluid from the suction inlet. The two fluids then mix in the throat section, where momentum is transferred from the high-speed motive stream to the suction fluid. After mixing, the combined flow passes through a diffuser, where velocity decreases and pressure is partially recovered before discharge. This process allows the pump to transport liquids, gases, or even a mixture of both.One of the major advantages of a jet pump is its lack of rotating parts. Because there are no impellers, seals, or bearings in the main flow path, maintenance requirements are often lower than those of mechanical pumps. This also makes the pump suitable for abrasive, corrosive, or contaminated fluids, depending on the materials of construction. Jet pumps can handle fluids containing suspended solids better than many traditional pumping systems, since the internal design is relatively open and robust.Another important benefit is their self-priming capability. A jet pump can often begin operating without manual priming, which is especially useful in deep-well systems, drainage applications, and remote installations. They can also be installed where access is limited, since the simple design reduces the number of components that may fail. In addition, jet pumps are often selected when a consistent flow is more important than maximum energy efficiency.However, jet pumps are not always the most efficient option. Because part of the motive energy is used to drive the suction process, overall efficiency is generally lower than that of some other pump types. For this reason, they are commonly used in situations where reliability, simplicity, and versatility are more valuable than energy savings. Proper selection of nozzle size, throat dimensions, and motive pressure is essential to achieve good performance.Jet pumps are used in water supply, wastewater handling, oilfield operations, chemical processing, vacuum generation, and geothermal systems. They are available in many configurations, including liquid jet pumps, steam jet pumps, and gas ejectors. Their broad operating range and adaptable design make them a practical solution for challenging fluid-moving tasks.