Piston Shallow Well Pump: A Comprehensive Guide for DIY Enthusiasts

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Piston shallow well pumps are a type of positive displacement pump that use a piston to move water from the well to the surface. These pumps are known for their efficiency, versatility, and ability to pump water at any pressure, making them a popular choice for various applications, including off-grid and remote water pumping systems.

Understanding the Technical Specifications of Piston Shallow Well Pumps

Piston shallow well pumps come with a range of technical specifications that can vary depending on the manufacturer and model. Here are some of the key specifications to consider:

Flow Rate

The flow rate of a piston shallow well pump is the volume of water it can move in a given period of time, typically measured in gallons per minute (GPM) or liters per minute (LPM). The flow rate can range from as low as 1 GPM (3.8 LPM) for smaller models to as high as 50 GPM (189 LPM) for larger, more powerful units.

Pressure

The pressure generated by a piston shallow well pump is the amount of force it can exert to move water, typically measured in pounds per square inch (PSI) or bars. These pumps can generate pressures ranging from 20 PSI (1.4 bar) to 100 PSI (6.9 bar), depending on the model and the power of the driver.

Stroke Length

The stroke length of a piston shallow well pump is the distance the piston travels within the pump cylinder, typically measured in inches or millimeters. Stroke lengths can range from 6 inches (152 mm) to 24 inches (610 mm), with longer stroke lengths generally providing higher flow rates and pressures.

Motor Power

The motor power required to operate a piston shallow well pump is typically measured in watts or horsepower (HP). Smaller models may require as little as 0.5 HP (373 W), while larger, high-capacity pumps can require up to 5 HP (3,730 W) or more.

Advantages of Piston Shallow Well Pumps

piston shallow well pump

Piston shallow well pumps offer several advantages over other types of water pumps, including:

  1. Efficiency: Piston pumps are known for their high efficiency, with some models achieving efficiencies of up to 80% or more.
  2. Versatility: Piston pumps can be run at a wide range of speeds, making them well-suited for use with variable-speed drives or direct connection to renewable energy sources like photovoltaic (PV) systems.
  3. Self-Priming: Piston pumps are self-priming, meaning they can lift water from below the pump level without the need for a separate priming system.
  4. Reliability: Piston pumps can be more reliable than centrifugal pumps, which are subject to internal moving contact and can be less efficient due to “slosh” in the process.

Potential Drawbacks and Considerations

While piston shallow well pumps offer many advantages, they also have some potential drawbacks and considerations to keep in mind:

  1. Susceptibility to Damage from Dirty Water: Piston pumps have tight clearances, seals, and wear points that can be more susceptible to damage from dirty or contaminated water.
  2. Maintenance Requirements: Piston pumps require more maintenance than some other pump types, with regular inspection and replacement of wear items like inlet and outlet flow checks.
  3. Installation Complexity: Piston pumps can be more challenging to install and maintain than some other pump types, particularly for DIY enthusiasts, due to their tight clearances and specialized components.

Selecting and Installing a Piston Shallow Well Pump

When selecting a piston shallow well pump for your application, it’s important to carefully consider the specific requirements of your project, including the depth of the well, the desired flow rate and pressure, and the available power source. It’s also crucial to ensure that the pump is correctly sized and installed to ensure optimal performance and longevity.

Pump Selection Considerations

  • Well Depth: Piston pumps are typically suitable for shallow wells up to 25 feet (7.6 meters) in depth, although some models may be able to handle deeper wells.
  • Flow Rate and Pressure Requirements: Determine the minimum flow rate and pressure required for your application, and select a pump that can meet or exceed those requirements.
  • Power Source: Consider the available power source, whether it’s a grid-connected electrical supply, a standalone generator, or a renewable energy system like a PV array.
  • Pump Sizing: Ensure that the pump is properly sized for your application, taking into account factors like the well depth, water table fluctuations, and any additional system components.

Installation and Maintenance

  • Follow Manufacturer Instructions: Carefully read and follow the manufacturer’s instructions for installing and maintaining the piston shallow well pump.
  • Proper Plumbing and Electrical Connections: Ensure that the pump is properly connected to the well and the water distribution system, and that all electrical connections are made correctly and safely.
  • Regular Maintenance: Perform regular maintenance tasks, such as inspecting and replacing wear items, to ensure the pump’s longevity and optimal performance.
  • Consult Professionals: If you’re unsure about any aspect of the installation or maintenance process, it’s best to consult with a professional plumber or pump specialist.

By understanding the technical specifications, advantages, and considerations of piston shallow well pumps, DIY enthusiasts can make informed decisions and successfully install and maintain these versatile and efficient water pumping systems.

References:

  • Field Evaluation of the Comanagement of Utility Low-Volume Wells Using a Surge Block with Simultaneous Pumping, EPRI, 2012.
  • Piston water pumps – why are they better?, NAZ Solar Electric Forum, 2011.
  • Guidance Needed for Shallow Well Set Up, DoItYourself.com, 2013.
  • Need Held: Lubricating Old Shallow Well Pump, Reddit, 2021.
  • Jet pump vs piston pump, Love Plumbing & Remodel, 2022.