Broken Water Lines at a Dairy

[Tom101]

Dear Sonny Lester.  Someone at your office said you could help me.  I have a dairy in north Texas with 3,000 head of cattle.  I have several water wells that feed a large storage tank behind the dairy.  There are two booster pumps which draw water from the storage tank and supply about 60 PSI to the dairy.  I used to have a big pressure tank but, the pumps would cycle on and off all the time, which would cause a 6" underground line to break on a regular basis.  The cycling also caused the motor starters and pressure switches to burn up at least once per year.  Last year a salesman talked me into buying two Square D Variable Frequency Drives.  We installed the drives and hauled off the old rusty pressure tank.  Now the VFD's are causing the underground pipe to break more often than the cycling pumps did.  When we turn off water the VFD doesn't slow down quickly enough, the pressure spikes and pow, another weekend of digging up and fixing the underground line.  Also when we first turn on water the VFD is slow to speed up the motor so, the pressure gets low and the pipes start shaking.  Will a Cycle Stop Valve solve my problem and how would I install it?

[Sonny Lester]

Tom,
I have seen alot of different dairys that have the same problem you have.
The reason being is that the dairys use alot of water and the drop down to a little amount of water in a hurry. The problem I have been seeing is the VFD can not slow down fast enough, I had a 50 gpm booster pumping into a manifold that had 20 2'' pipes off it going to the dairy. When they would use 40 to 50 gpm it work ok. Then when they would shut the water down to 5gpm in a hurry I thought that the 20 2'' gate valves were going to blow through the ceiling. Instead it would blow the line in the yard, we would be fixing another one. With the Cycle Stop Valve it works instantly to any change or flows so we were able to pull the drives off and go from any flow as fast as we want, the valve works off pressure and opens and closes as any demands change. You need to put a CSV on your system, on the discharge of your pump with a 20 gallon tank down steam of the valve. Get a 50/70 psi switch and set the valve at 60psi. It will make your system effecient in alot of ways with constant pressure at any flow. Thanks, Sonny Lester