DIY Doctor UK DIY Forums

i am trying to install pop-up lawn sprinklers, which use harvested water, pumped out of my tanks, via garden taps fixed to my house wall (the pipes supplying ther taps are all inside the cavity.) The pressure gauge on my pump shows 5.5 bar when not in use, and drops to 3 bar when one hose it run at full.I get about 20 litres / min at the tap with a hose fitting on..
My garden taps are all 1/2", and are normally connected down to 1/2" hose fittings.

If i run this via a hose to my sprinkler, i only get a 10m throw radius, but i think i should be able to get closer to 15m The sprinkler has a 25mm connection, so of course i have had to go from what looks like 25mm in the wall, via a 1/2" tap, via 1/2" hose, to a 1/2">>>25mm joint to the sprinkler.
If i ran 25mm all the way from the wall to the sprinkler ( ie new tap which doesnt reduce), would i get more flow rate? and therefore a longer spray radius?
I should have paid more attention in physics at school.
many thanks to anyone who can help.

yes you'd get a greater flow rate but the pressure may actually drop, not increase, you are reducing the resistance - consequently the pressure.

in other words, you'd be getting more water out but the radius would remain the same - possibly smaller.

it's all down to what pressure you pump can give, anyway. not so much the flow rate although the two are linked. 3 bar is ok but isn't a huge amount of pressure. i have 3 bar incoming mains and tried to run various high pressure sprinklers from it to no avail. had to swap in for one that works well on lower pressure.

so two options: bigger pump or different sprinkler.

you could try to run all in larger pipe but could end up being a lot of work for nothing.