Constant Pressure Pump Control Valves
CSV1W / CSV1Z / CSV2W General Information
The Cycle Stop Valve model CSV1W, CSV1Z, and CSV2W are pump control valve that automatically adjust pump output to match variable flow requirements. Downstream of the CSV1W, CSV1Z, and CSV2W, pressure remains constant as long as demand is between the upper and lower limits of the valve. The 1" CSV1W and CSV1Z handle from 1-25 GPM and the 1 1/4" CSV2W handles from 5-50 gpm.
As flow rates vary, the change in pressure causes the valve inside these models to modulate closer to or farther away from the valve seat. This enables the pressure downstream of the CSV to remain constant depending on pressure fall off.
When there is no longer any demand on the system, the pressure begins to rise and the valve is pressed against the valve seat. The valve and seat are designed to never be able to completely seal. The non-closing seat is sized to allow flow of approximately 1 gpm on the 1" valves or 5 gpm on the 1 1/4" valve. As this flow continues past the seat, water begins to fill the pressure tank downstream of the CSV. As the pressure tank slowly fills, the system pressure will slowly rise to pressure switch shut off. (Note: Pressure switch shut off pressure must always be higher than the constant pressure held by the CSV).
Regardless of tank size, when the tank fills, the pressure downstream of the CSV rises to pressure switch shut off point and the pump will be shut off. As flow is again demanded from the system, the pressure tank will empty and the pressure switch will start the pump.
Model CSV1Z and CSV1W are dual threaded and are available in 1" female NPT/1 1/4" male NPT. The "Z" model is adjustable from 15-150 PSI, the "1W" model is preset to 60 PSI and is adjustable from 40-100 PSI. The CSV2W is available in 1 1/4" female NPT thread and has pressure settings available from 25-75 PSI or 50-120 PSI. There can be no more than 125 PSI maximum differential pressure across any of these valves. (Difference in pressure between inlet pressure and outlet pressure).