The Cycle Stop Valve or CSV can save money and energy directly and indirectly. A Variable Frequency Drive or VFD system may use a little less energy than a CSV system at low flow, but the parasitic losses and reduced efficiency of the motor running on a VFD, means the VFD uses more energy at high flow. Over the full range of flow, the amp draw or energy reduction that happens as a CSV throttles the output of a pump can be almost exactly comparable to the energy reduction of a VFD system. To verify this you only need to use the standard Brake Horse Power equation. If you know your flow rate, head, and efficiency the horsepower can be easily figured using our Horse Power Calculator.

However, there is nothing more efficient that a properly sized pump running at it's best efficiency point. Any time you reduce the RPM with a VFD, or throttle the output with a valve, a pump is using more energy per gallon produced, than when the pump is running at it's best efficiency point and full RPM. There are cases where a CSV or VFD can save energy directly. When the flow rate required is between 60% to 90% of the max flow, and rapid cycling into a pressure tank causes multiple motor starts with high inrush currents, a CSV or VFD will reduce the energy consumption directly. The lower the flow rate required, the more energy per gallon is used with a VFD or a CSV. Because head is lost by the square of the pump speed, when a static head or constant pressure must be maintained, a pump cannot be slowed down enough with a VFD, to save anymore energy than a CSV.

To see the indirect ways that a CSV saves energy, we must compare it to the other types of pump control. Cycling on and off into a pressure tank is one of the fastest ways to destroy a pump system. Because of cycling, the average life of small submersible pumps is only about 7 years. Those that cycle the most only last 2 years, while those that cycle the least last about 12 years, hence a 7 year average. Even with a fairly large pressure tank, cycling destroys every component in a pump system. Cycling flexes the bladder in a pressure tank, until the bladder breaks like bending a wire back and forth. Cycling destroys pressure switches, start capacitors and starting relays. Cycling torques the pipe in the well, until the down hole wire is rubbed bare. Cycling can strip pump splines and loosen impellers. Cycling also destroys the motor or strips the motor splines. //

Since cycling is one cause of most pump system failures, eliminating 80% of the cycles with a Cycle Stop Valve, can triple or quadruple the life of every component in the pump system, compared to a pressure tank only system. Because a CSV system runs on standard sinusoidal power at a constant RPM, there are no voltage spikes, harmonics, resonance frequencies, or additional heat produced. A CSV system can more than quadruple the life of a pump system when compared to a VFD. A pump system that last 15 years, can save a tremendous amount of energy over having to replace the pump system every 5 years. Taking into consideration that the CSV system uses a pressure tank that is a fraction of the size and cost of larger pressure tanks, can add substantially to the savings. Reductions in square footage needed to house a large pressure tank, and saving the heat required for that extra square footage, can add even more to the energy savings. Lastly consider the energy used to mine, manufacture, transport, install, and recycle the additional pump systems destroyed by cycling or VFD's.