Yes, many well pumps have built-in check valves, although installing a separate check valve is often recommended.
While some well pumps come equipped with an internal check valve, relying solely on this built-in valve might not be sufficient for optimal performance and longevity of the system. A secondary check valve, installed in the discharge line close to the pump (ideally within 25 feet and below the water drawdown level), adds an extra layer of protection.
Why a Second Check Valve is Recommended:
- Redundancy: A second check valve acts as a backup. If the built-in valve fails, the external valve prevents water from flowing back into the well.
- Preventing Backflow: Check valves prevent water from flowing back down the well when the pump shuts off. Backflow can cause water hammer, damage the pump, and reduce efficiency.
- Maintaining Prime: By preventing backflow, the check valve helps maintain the prime of the pump, ensuring it can readily pump water when needed.
- Extending Pump Life: Reducing the strain of repeated starts and stops due to backflow can extend the life of the well pump.
Types of Check Valves:
Common types of check valves used in well pump systems include:
- Spring-loaded check valves: These valves use a spring to close the valve when flow stops.
- Swing check valves: These valves have a hinged disc that swings open to allow flow and closes when flow reverses.
The best type of check valve for a particular well pump system depends on factors such as water quality, flow rate, and well depth. Consult with a qualified well pump technician for specific recommendations.
In summary, while many well pumps include a built-in check valve, adding a secondary check valve in the discharge line is a prudent measure to ensure reliable operation, prevent damage, and extend the lifespan of the well pump system.
