A pressure tank for a water well works by using compressed air to maintain water pressure in your home, reducing the frequency of the well pump turning on and off.
Here's a breakdown of the process:
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Air Compression: The tank contains both air and water. As water is pumped into the tank, the air inside is compressed.
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Pressure Buildup: The more the air is compressed, the greater the water pressure becomes. This is because the compressed air exerts force on the water. The reference explains: "When water is pumped into a tank containing air, the air is compressed, putting the water under pressure. The more the air is compressed, the greater the water pressure."
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Pump Shut-Off: When the water pressure reaches a pre-set level, typically between 40 to 60 pounds per square inch (psi), a pressure switch signals the well pump to automatically shut off.
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Water Draw: When you open a faucet or use water in your home, the pressurized water in the tank is pushed out.
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Pressure Drop & Pump Activation: As water is drawn from the tank, the air pressure decreases. Once the pressure drops to a lower pre-set level (e.g., 40 psi if the upper limit is 60 psi), the pressure switch activates the well pump again to refill the tank and re-pressurize the air.
In essence, the pressure tank acts as a storage reservoir and pressure regulator. It helps:
- Maintain consistent water pressure: Provides a steady flow of water even when the pump isn't running.
- Extend pump life: Reduces the number of times the pump cycles on and off, which can prolong its lifespan.
- Prevent water hammer: Minimizes the shock to pipes caused by sudden changes in water flow.
