|
|
Multiple Pressure Settings from a Single Pump System
Using a Cycle Stop Valve, a pump or a pumping station can be designed to hold a single
constant pressure. In some systems different pressure are required throughout
different areas. The pump or station should be designed to operate at the highest
pressure required in the system. Anywhere in the system that a line with a lower
pressure is required a simple pressure reducing valve can be used.
An example would be a pit mine where the pump station at the bottom might be
required to produce 200 PSI. Only 40 PSI may be left for the sprinklers used to wet
down the highest road in the pit. On the lower roads the pressure increases as the
elevation decreases. The water line at the lowest road is close to the pump station
and sees 200 PSI. A simple pressure reducing valve should be used at each of the
taps on the way out of the pit. These pressure reducing valves on the water lines at
each level can be set at 40 PSI. Each level now has a steady 40 PSI from top to
bottom of the pit.
Another example would be a golf course that needs 120 PSI for the main irrigation
sprinklers, 50 PSI for the lines at the club house, and 10 PSI for the drip system
irrigating the trees on the border. The main pump station is set up for the 120 PSI.
The line is tapped at the club house, a pressure reducing valve is installed, and set at
50 PSI. The 120 PSI line is tapped again over by the trees and another pressure
reducing valve delivers 10 PSI to the drip system.
Another example would be an irrigation system that uses up to 1,000 GPM at 50 PSI
for pop up sprinklers. A small section that needs irrigating is on top of a hill. This
section only requires 100 GPM but needs an extra 50 PSI to reach the top of the hill.
A small booster pump can be tapped into the main irrigation line going up the hill.
This 100 GPM booster pump picks up water from the first pump at 50 PSI and boost
it to 100 PSI. This booster would come on at 100 PSI and the Cycle Stop Valve would
maintain this 100 PSI with flows from 5 GPM to 100 GPM. When there is zero flow
on top of the hill the Cycle Stop Valve on the booster pump allows a small tank to fill
to 110 PSI and the booster is shut off. Other small boosters can be added anywhere
in the system they are needed. This type system allows the main pump to run at the
low pressure that is needed for the majority of the irrigation. When the irrigation is
needed at the top of the hill only a small portion of the main flow must be boosted to
a higher pressure.
|