Rotary jet pumps (also known as pitot tube pumps) are a type of pump with a rotating casing combined with a stationary pitot tube, suitable for small flows but high heads. The compact structure and few moving parts make the pump suitable for many services where multi-stage centrifugal pumps are not economically viable.
The fluid enters the rotating casing and rotates with the casing, forming a fluid ring that is subject to centrifugal force, resulting in high pressure in the outer region. The stationary pitot tube placed in this fluid ring collects the pressure and leads the fluid to the discharge port. High head is achieved with just one rotating stage instead of multiple impeller stages.
According to many manufacturers, in this type of pump, the seal typically withstands a lower suction pressure than the discharge pressure, so the sealing conditions are easier than those of multi-stage pumps. Still, it is necessary to select seals according to the medium, temperature, and rotation speed, and check the appropriate drainage and cooling diagrams.
At very small flows and high heads, rotary jet pumps are often more compact and have fewer stages. At large flows, centrifugal pumps often achieve higher efficiency, so it is necessary to compare based on actual operating points.
Monitor vibration, temperature, and seal leakage, check the wear of the pitot tube and rotating casing periodically, and keep the fluid clean.
SNS-VN supports consulting on the selection of rotary jet pumps and seals according to your operating points. Please contact us for a quote.