A peripheral pump, also known as a regenerative pump or turbo pump, is a type of centrifugal pump that is designed to generate high pressures at relatively low flow rates. It works by having a rotating impeller with numerous radial blades that pass very close to the pump casing, allowing fluid to be “recirculated” in small chambers between the impeller and the casing. As the fluid is pushed around the perimeter of the impeller, energy is continuously added to the fluid, increasing its pressure.

How Peripheral Pumps Work:

  • Impeller Design: The impeller has multiple radial blades that generate high pressure as the fluid is pushed through the pump.
  • Perimeter Flow: The fluid enters the pump, is accelerated by the impeller blades, and is directed along the edge or periphery of the impeller. The pump “regenerates” pressure with each pass of the fluid around the blades, resulting in significantly higher pressure than a traditional centrifugal pump of the same size.
  • Low Flow, High Pressure: Peripheral pumps excel in applications requiring high pressure with lower flow rates, making them ideal for specific tasks that standard centrifugal pumps may not handle efficiently.

Applications of Peripheral Pumps:

  1. Boiler Feed
    • High Pressure Requirements: Peripheral pumps are often used in boiler feed applications where the supply of water to the boiler needs to be at high pressure to ensure efficient steam production. These pumps are ideal for small to medium-sized boilers, as they can generate the required high pressure with a compact pump size.
  2. Pressure Boosting Systems
    • Domestic Water Supply: In residential and small commercial buildings, peripheral pumps are commonly used in pressure boosting systems to increase water pressure for taps, showers, and other fixtures. They are also used in combination with pressure tanks to maintain consistent water pressure throughout the system.
    • Industrial Pressure Boosting: In industries where a high-pressure water supply is necessary (e.g., cleaning processes or water jet cutting), peripheral pumps provide an efficient solution.
  3. Cooling and Air Conditioning Systems
    • Peripheral pumps are used in cooling systems to circulate water or other cooling fluids under high pressure. Their ability to operate efficiently at low flow rates with high pressure makes them suitable for compact HVAC systems and small industrial cooling units.
  4. Irrigation Systems
    • Small-Scale Irrigation: Peripheral pumps are used in agricultural applications where small-scale irrigation systems require high-pressure water delivery over shorter distances. These pumps are often used in garden irrigation, greenhouse watering, or localized irrigation setups.
  5. Water Treatment Plants
    • Chemical Dosing and Transfer: In water treatment processes, peripheral pumps are used to inject chemicals, such as chlorine or flocculants, into the water at high pressure. Their precise control and ability to handle low flow rates make them suitable for dosing applications.
    • Filtration Systems: Peripheral pumps are sometimes employed in filtration systems that require high-pressure water to drive water through fine filters.
  6. Firefighting Systems
    • High-Pressure Water Delivery: Peripheral pumps are used in portable firefighting systems and small fire suppression setups where high pressure is needed to distribute water effectively, especially in smaller installations.
  7. Heating Systems
    • Circulating Hot Water: In heating systems such as hydronic heating, peripheral pumps are used to circulate hot water under pressure, ensuring that heat is distributed evenly throughout the system. These pumps are commonly found in smaller or localized heating systems.
  8. Industrial Applications
    • Machine Tool Cooling: Peripheral pumps are used in industrial machine tool systems for cooling purposes, such as delivering coolant to machine tools under high pressure. This ensures that the tools remain cool during cutting, grinding, or drilling operations.
    • Hydraulic Circuits: These pumps are employed in small hydraulic systems where a continuous, high-pressure fluid flow is required, such as in hydraulic presses, jacks, or lifting equipment.
  9. Chemical Processing
    • Handling Non-Corrosive Fluids: Peripheral pumps are used to transfer fluids that require high-pressure delivery but are non-corrosive, such as in small-scale chemical processing or laboratory environments.
    • Precise Fluid Transfer: Due to their ability to provide stable flow rates at high pressures, peripheral pumps are ideal for metering and dosing in chemical processing where precise amounts of fluid need to be transferred.
  10. Fuel Transfer
    • Fuel Oil Delivery: Peripheral pumps are used in the delivery of fuel oils (such as diesel or kerosene) to boilers, burners, or generators, ensuring a steady supply of fuel at the required high pressure.
    • Gasoline and Diesel Transfer: In smaller fuel transfer applications, these pumps can be used to move gasoline or diesel from storage tanks to dispensing systems.

Key Characteristics of Peripheral Pumps:

  1. High Pressure at Low Flow Rates:
    • Peripheral pumps are specifically designed for applications where high pressure is required but flow rates are relatively low. This makes them different from standard centrifugal pumps, which typically provide higher flow rates at lower pressures.
  2. Compact Size:
    • These pumps are often much smaller than centrifugal pumps that provide similar pressures, making them ideal for applications where space is limited.
  3. Self-Priming Capabilities:
    • Many peripheral pumps have self-priming capabilities, meaning they can remove air from the suction line and start pumping fluid without requiring manual priming. This makes them useful in applications where the pump may need to handle air or gas within the fluid.
  4. Cost-Effective:
    • Peripheral pumps are typically more affordable than other types of high-pressure pumps, such as positive displacement pumps, making them a cost-effective option for specific high-pressure, low-flow applications.
  5. Handling of Gases:
    • Peripheral pumps can handle small amounts of gas mixed with liquid without losing prime or efficiency. This makes them suitable for applications where gas may be present in the fluid, such as in pressurized systems or where cavitation might occur.
  6. Low Maintenance:
    • With fewer moving parts and a simpler design compared to other pump types, peripheral pumps require less maintenance, contributing to their reliability and cost-effectiveness.

Limitations of Peripheral Pumps:

  • Limited to Low Flow Rates: Peripheral pumps are not suitable for applications requiring high flow rates. They are designed to excel in delivering high pressure at low volumes.
  • Not Ideal for Viscous Fluids: These pumps are not suitable for handling viscous fluids, slurries, or liquids with high solid content, as the impeller and casing design are optimized for low-viscosity liquids like water or light oils.
  • Cavitation Risk: While they can handle small amounts of gas in the fluid, peripheral pumps can be prone to cavitation if the suction conditions are not managed properly, especially in high-temperature applications.

Conclusion:

Peripheral pumps are an excellent choice for applications requiring high pressure at low flow rates. Their compact size, efficiency, and ability to handle various fluids make them versatile for use in water supply systems, boiler feed applications, HVAC systems, irrigation, and chemical processing. They offer a cost-effective solution for high-pressure fluid handling in many residential, commercial, and industrial settings.