Control Valve
Application
Guide
Nelson Irrigation Corp. 848 Airport Rd. Walla Walla, WA 99362-2271 USA Tel: 509.525.7660 Fax: 509.525.7907 E-mail: [email protected] Web site: www.nelsonirrigation.com
PRESSURE CONTROL REPLACEABLE SENSITIVITY BUSHING
This sensitivity bushing is designed to be easily replaced and is used to change the pressure control response
in order to solve pressure cycling problems or to make the valve more accurately control pressure.
APPENDIX A
17
EXAMPLE 1: A drip irrigation system requiring 10 PSI: the upstream pressure does not change
dramatically with changes in flow rate. The valve is close to the drip tape. Choose the 5-50 PSI
pressure control because it will maintain 10 PSI more accurately than the higher pressure controls.
Choose the red sensitivity insert to further increase the accuracy of downstream pressure.
EXAMPLE 2: A deep well turbine feeding some wheel lines and a pivot: the upstream pressure varies
significantly with changing flow rate and long mainlines are used. Choose the 25-200 PSI pressure
control because it will not try and make small changes to this very dynamic system. Use the black
sensitivity insert to further dampen the pressure controls response. This system is like a long freight
train ... it is not always constructive to micro manage the pressure.
