Use of Check Valves in Submersible Well Pump Installations
By: Shopify APIWhat Is a Check Valve?
A check valve is a valve used to prevent backflow in a piping system. The pressure of the liquid passing through the pipe opens the valve, while any reversal of flow closes it. In a well pump system, check valves help maintain pressure when the pump shuts off and prevent backspin, upthrust, and water hammer.
Do I Need a Check Valve on My Submersible Well Pump?
Yes. It is recommended that at least one check valve be installed in all submersible well pump installations. Many well pumps have built-in check valves, but even if yours does, we recommend installing an additional check valve in the discharge line within 25 feet of the pump and below the draw-down level of the water supply. In deep wells, we recommend installing check valves every 200 feet to distribute the weight on each valve.
What Type of Check Valve Should I Use?
Swing type check valves should never be used in a submersible well pump installation. They have a slower reaction time and can cause water hammer. Spring-loaded check valves should be used instead — they close quickly and help prevent water hammer. The check valve must be properly sized to meet the pump’s flow and pressure conditions, and its pressure rating must exceed the maximum pressure of the pump.
Shop Check Valves
We carry Flomatic spring-loaded check valves designed for submersible well pump installations:
- Flomatic 80E-Enviro Check Valve 2"
- Flomatic 80E-Enviro Check Valve 3"
- Flomatic 80E-Enviro Check Valve 4"
- Zoeller Unicheck PVC 1-1/4" or 1-1/2" — compact option for smaller systems
Shop Submersible Well Pumps
Need a new or replacement submersible well pump? We carry trusted brands for residential and commercial applications:
- A.Y. McDonald 0.5 HP Thermoplastic Well Pump & Motor 15 GPM
- A.Y. McDonald 0.75 HP Thermoplastic Well Pump & Motor 15 GPM
- A.Y. McDonald 0.75 HP Thermoplastic Well Pump & Motor 25 GPM
- A.Y. McDonald 1.5 HP Thermoplastic Well Pump & Motor 20 GPM
- Franklin Electric Super Stainless 4" Well Motor 0.5 HP 115V
- Franklin Electric Super Stainless 4" Well Motor 0.75 HP 230V
Why Are Check Valves So Important? The Risks of Skipping One
Backspin
When the motor stops, water in the drop pipe can flow back down the discharge pipe if there is no check valve or a failed one. This flow can cause the pump to rotate in reverse. If the pump starts while backspinning, it can cause excessive force that breaks the pump shaft, damages impellers, or causes bearing failure.
Upthrust
With a failed or missing check valve, the pump starts with zero head pressure. When there is low or no pressure, the impellers “float” up and wear on the diffusers above. This repeated wear causes premature failure of both the pump and motor.
Water Hammer
A failed or leaking check valve can create a vacuum in the discharge piping. When the pump starts, water moving at high velocity fills the void and strikes the stationary water above it, causing a hydraulic shock. This shock can split pipes, break joints, or damage the pump and motor.
Related Guides
- 📖 Troubleshooting Submersible Well Pumps 101 — Pump Does Not Start
- 📖 Troubleshooting 4" Submersible Motor: Insulation & Windings Resistance
- 📖 Water Well Drop Pipe Selection Guide
- 📖 Using a Safety Line With Submersible Well Pumps
Need Help Selecting the Right Check Valve or Pump?
Not sure which check valve or pump is right for your system? Our experts can help you select the correct size and type for your flow rate, depth, and installation requirements.
Call 855.329.4519, visit www.rcworst.com, or email Customer.Service@RCWorst.com.
