The following pictures are of an impeller/diffuser, and motor thrust bearing from a 2 HP submersible pump. This was an accelerated test to see how Cycle Stop Valves affect pumps and motors. This pump was actually in the well for over 12 years. During that 12 years, we accelerated the work on the system to simulate a pump system with over 30 years of service.
This pump ran for several years at only 1 GPM. It also ran for several years at varied flow rates from 2 to 25 GPM. All of this time it also supplied two houses with a pressure tank than only held 2.5 gallons of water. So it was also allowed to cycle on and off for intermittent demands. In 12 years we did everything we could think of to try and destroy this pump.
The pump was finally removed for inspection and the following was observed. There is absolutely no down thrust, upthrust, or radial damage to the impeller, diffuser, shaft, or bushings in the pump. The thrust bearing in the motor still looks like brand new, and the motor windings tested and looked perfect.
As you can see from these pictures, the wearable parts of the pump and motor still look perfectly new. There are many thousands more pumps that have lasted this long or longer using a CSV. This particular one we watched everyday and subjected it to the worst possible conditions for over 12 years. Anyone who thinks a Cycle Stop Valve can damage a pump or motor in anyway, should look very closely at these pictures.
I should also say that previously the average life of a pump in this test well was less than 2 years. This CSV made this pump last 600% longer than the average, and it would still be working today if I had not just wanted to see what it looked like.
