On 7/25/11 1:20 PM, Steve B wrote:
"gardenlen" wrote in message
...
g'day steve,

could there be a limit to how many head can be run or added to system?
if you add heads in then that effects how well what was there before
works, might need to divide or get heads that deliver at lower
pressure??

or somehow increase the pressure in?

Have considered a booster pump, as this is a gravity fed/booster pump
situation from a local mountain stream, and a holding reservoir. Pressure
varies a lot according to use.

Steve

My neighborhood is on a water system that is gravity-fed from a
1,000,000 gallon tank up on a hill higher than any house. The pressure
in my lines is high enough that a hose turned on full will writhe and
snap like an injured snake.

I have drip emitters for three dwarf citrus in large flower pots (about
21 inches across and equally deep). These emitters are tied into my
regular garden sprinklers. Despite the available pressure, each emitter
is on a separate sprinkler valve.

For my garden, there are 7 valves: 2 in front and 5 in back (popup and
shrub heads). There is a separate (8th) valve for the drip system for
my roses in front on the far side of my driveway (seven emitters). And
there are 4 valves for my hill (rotating heads). Since emitters have a
much lower flow rate than bubblers, I can run the drip system for the
roses while another valve is open, but I cannot otherwise run 2 valves
at the same time.

All of this is to indicate that the "load" on a sprinkler system must be
balanced even when the available pressure is quite high.

Fortunately for me, the 7 garden valves and the drip valve for the roses
are on a clock. I don't have to keep running outside to shut one valve
and open another. I do the 4 hill valves manually, but my hill is
irrigated only every third weekend.

--
David E. Ross
Climate: California Mediterranean, see
http://www.rossde.com/garden/climate.html
Gardening diary at http://www.rossde.com/garden/diary