A standard pressure switch and pressure tank is used for starting and stopping the pump. The CSV is installed before the pressure tank and switch, and is usually adjusted to the middle of the pressure switch setting. Small or large pressure tanks can be used with these devices, and the size of the tank determines the exact pressure settings. When a tap is opened, the compressed air in the pressure tank, forces water from the tank to supply the usage.
The pressure drops from 60 to 40 PSI as the tank is emptied. This utilizes all the water stored in the pressure tank, and keeps the pump from having to start for small, intermittent uses of water.
At 40 PSI, the pressure switch starts the pump. The pump will continue to run, and the pressure will remain constant, as long a small amount of water usually 1 to 5 GPM continues to be used. This keeps the pump from cycling on and off during long showers, small irrigation zones, and low heat pump discharge rates. The larger the pressure tank, the less number of times the pump must start for intermittent uses of water such as ice makers, rinsing toothbrushes, or flushing a toilet.
The smaller the pressure tank, or the more narrow the pressure switch differential, the more often the pump will need to start but, the sooner constant pressure is achieved. The CSV creates a mechanical soft start and soft stop, which eliminates water hammer. When the points in the pressure switch open, no voltage is maintained on the system while the pump is off.
The CSV does not use any power itself when the motor is running, or when the motor is off. A CSV controlled pump uses the least amount of energy per gallon when the pump is delivering maximum flow. The pump is sized to the maximum GPM or peak requirements of the system. When using flow less than maximum pump output, the CSV reduces the output of the pump accordingly. This keeps the pump running continuously, when flow rates required are less than maximum pump output.
Very small flows or leaks, less than 1 to 5 GPM are fed by the pressure tank, as the pump slowly cycles on and off, depending on the size of the pressure tank, and the pressure bandwidth.
A constant 50 PSI will deliver a consistent spray pattern for sprinklers, compared to when the pressure is continually changing between 40 and 60 PSI. Large water systems that supply multiple houses, communities, and cities, can also use CSV controls.
Varying the pump flow to match the usage eliminates the need for water towers, large hydro-pneumatic tanks, or multiple pressure tanks.
Once the pump has come on, adjust your demand to GPM. This reduced demand is important. You do not want to set the valve with more gpm going through it than this. With the adjustment stem loosened out, the valve is going to try to hold the low pressure in the adjustment range. The CSV2W is adjusted by turning the adjustment stem clockwise to increase downstream pressure and counter clockwise to decrease downstream pressure.
Adjust the CSV2W until the pressure steadies at your desired working pressure. Tighten the lock nut. The valve is set. The CSV2W works with your pump sytem using pressure. The CSV2W has to be set within your existing system pressure parameters to work correctly. The pressure tank pressure needs to be psi lower than your pressure switch cut in pressure. The pressure switch cut off pressure needs to be higher than the CSV2W working pressure.
This allows for tee offs between the well head and the pressure tank such as a frost free hydrant at the well. Model CSV should be hand tightened using Teflon tape on threaded ends. Four to seven wraps of Teflon tape is usually sufficient. All connections should be water tight. The pressure tank should be installed on a tee or tank cross. It should be installed downstream of the of the CSV1. Pressure switch and other controls must be installed as close to the tank as possible.
Precharge pressure in the tank should be PSI lower than pressure switch start point. Pressure switch shut off pressure must be higher than the Cycle Stop Valve pressure. How much higher depends on your pressure tank size. The smaller the tank, the closer the cut in pressure and CSV pressure should be But, cut out pressure always has to be higher than the CSV pressure.
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