IBC tank water pressure

redser7

Hi there - I'm putting the pieces together for an automatic watering system for the tunnel. I just bought a timer from Lidl and looking at the booklet it says the operating pressure is 0.34 - 8.27 bar or 34.5 - 827 kPa. Minimum rate of flow is 28 lts a minute.
So before I hook it up and test it and maybe ruin my chances of a refund if it doesn't work, would a 1000 lt IBC have enough pressure? I am going to raise it about 2 foot above the soil level.
Thanks a lot

redser7

In case anyone is interested, the kind farmers across the site tell me 0.34 is way too high for an IBC. You'd have to have the tank a fair few metres in the sky Lucky I kept the receipt. So steer clear of Lidl timer unless you are using a mains garden tap. Apparently the Aldi timer (which hopefully comes out soon) works on much lower pressure.

magicbastarder

a quick google suggests that pressure increases by 0.1 bar for every metre of water.

redser7

Thanks, did a good bit if googling first but couldn't work out if that's in a pipe, effect of diameter of pipe, does it matter that it's 1m cube, reducing to 1/2 inch pipe, blah blah blah. Physics never was my strong point

magicbastarder

generally speaking, unless the pipe is thin enough to affect the pressure, pressure is basically just down to the height of the water above the point you're measuring at.

e.g. pressure at one metre below the surface of a lake is the same as pressure one metre down in a water butt.

redser7

Cheers, it is good to know these things. Makes sense putting it that way. Would look odd, an IBC 3.4 meters off the ground. Don't know why the unit would need such a high pressure for the valve. Surely the battery could just open and close it. Ah well.

Discodog

Connecting it won't effect a Lidl refund - how can you know that it's faulty without connecting it ? Every timer that I have used has a simple motorised valve & is not affected by minimum pressure.

redser7

Yeah but it's not faulty so it needs to be in prestine condition to get a full refund as far as I understand the website.
Anyway, this one is fairly unique in that it does need a minimum pressure in order to work, it says in the booklet. It also says it needs to be attached to a mains tap, which would give it that pressure. Pity you can't tell this without buying the product and opening it.
Banking on the Aldi one coming out soon, I know for a fact it will work, have seen them around the allotments.
Cheers

Discodog

I would guess that it relies on the water pressure to open or close the valve. I have bought power tools from Lidl, used them, not been happy & have received a full refund.

Macy0161

On another (UK) site I read before of somebody used a solar fountain pump to feed a header tank from an ibc. Then you could have the header tank higher to get the pressure. Header tank fills during the day (with an overflow back to the ibc), timer set for either evening or early the following morning.

I was going to bástardise that idea myself, but have never got around to it...

Just to add, I also thought it'd be no harm to circulate the water as well rather than have standing water.

redser7

Thanks for that, very interesting. Would love to experiment more. Just in the first year at the plot the expenses are fairly high But in coming years would love to try out different things. Had a mad idea using an old mobile set on vibrate and a motion sensor. Could maybe be rigged up to set off watering or an arm for ventilation Send a free text to the tunnel from the comfort of your own home!

The Master.

Hi everybody. I just installed one of these in my garden but ive only got it 0.5 metres off the ground. How high does it have to be to give decent pressure as its woeful at the moment and i have it filled!!!

The Master.

Hi everybody. I just installed one of these in my garden but ive only got it 0.5 metres off the ground. How high does it have to be to give decent pressure as its woeful at the moment and i have it filled!!!

iainBB

The Master. wrote: »

Hi everybody. I just installed one of these in my garden but ive only got it 0.5 metres off the ground. How high does it have to be to give decent pressure as its woeful at the moment and i have it filled!!!

Stupid question of course but the lid is off right when you open the value?

magicbastarder

also, how high is the valve where the water is coming from? what matters is the drop from the top of the water level to where the water is coming out.
i.e. if it's raised 50cm and is only 50cm full, you'll only get the 1m worth of pressure in a hose where the hose is laying flat on the ground.
standing with the hose held at your waist would result in near zero pressure in the above scenario.

The Master.

The outlet valve is right at the bottom of the tank and the tank is full. and i did take the lid off to allow the air to get in. As i said its only 50cm of the ground with the blocks i had so its possible to raise it with pallets but dont know how high.
Does either the length of hose or diameter of the hose have an effect on the pressure? Ill take a picture of it.

magicbastarder

the outlet valve is at the bottom of the tank - but what does it feed into? if it feeds into a hose which you hold higher than the outlet valve, you will not get the pressure at the valve.

_Brian

To get any decent pressure you'll need feet of head height not inches, impractical in most cases.

Most likely need and "on demand" water pump, Lidl Aldi have them from time to time for small money.