On Sunday, February 16, 2020 at 6:59:04 AM UTC-5, Dean Hoffman wrote:
On 2/16/20 4:59 AM, Jerry Salinsky wrote:
I am thinking of installing a 1 HP water pump to water my lawn. How many
sprinklers can it support? Is there a rule of thumb or some math to
calculate?

What would happen if I don't install enough spirnklers? I worry the
pressure in the pipe system would be high and ruin the pump.

The sprinkler is this type:

https://upload.wikimedia.org/wikiped...echanism_2.jpg

It looks like this is what you have:
https://www.rainbird.com/products/35a-series
There's a chart on the lower left corner that gives you pressure and
flow requirements. It looks like you need a minimum of 30 psi to run it.

And there is an output chart for the pump too. A big unstated here is where
is the water coming from? A 20 ft well, above ground tank, etc. Pipe size?
That sprinkler type is unusual for watering a lawn, typical is a pop up rotor
type, though you could use it. If it's a 1hp water with good supply of
water at ground level, it could probably support half a dozen of those.
With a typical water pump for such an application, it would be impossible
to get a dangerously high pressure, there is a max that it's incapable of
exceeding.