Rainwater Harvesting - pumps etc

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If you see the diagram - I would plan to put the pump inside the shed where the pipe enters the building.

I can raise the feeder tanks so they are slightly above the pump. I expect the water level to be considerably above the pump. This way it can live indoors and be easily accessible. I expected some kind of inline pump.

Could I use something like this as the switch? When it drops to the bottom it comes on and raises to the top it switches off? Mount it vertically in the top of the header tank?

http://uk.rs-online.com/web/p/level-sensors-switches/4928946/

 
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The only criticism of those floats is with slightly cruddy water is they gum up.

A bit of duckweed got stuck around our canal basin level control, the reservoir valves were happily pouring water in to an already full canal.

 
at sea level the max vacuum would be -1 bar, or there abouts. you saying will suck 20m implies 20m height. if it can prime at 1mtr away, it should be able to prime at 1000mtr away if its the same height (but it would take a bit longer to do so)

 
There's a magic height where water gets very hard to pump - I had a feeling it was something like 10m - something to do with the intrinsic weight of the column of water.

Anyways

 
I would say that a 20/25mm suction line is pretty inadequate unless you are willing to suffer lots of cavitation, based on the data seen so far.

With that in place I would be looking to use it as a delivery line, presuming that you are taking the water from the single exterior IBC to the 6 internal ones.

One thing that I haven't mentioned, will the support structure for the 6 IBC's on the roof of the lab take in excess of 6000kg of load over a 3m x 1m area?

 
The 6 IBC containers will be outside and store the water. There will be a small header tank on the lab roof that will hold the immediate supply for a pressure washer - ~200 litres - whatever I can spec for little money. The header tank will hold more water than I am ever likely to use in a session.

I don't care how slowly the header tank fills. I don't mind if there are a few splutters or bubbles.

If it simply cannot work then I won't do it. So far all that is in place is the pipe underground.

 
There is ~2m of pipe stuck out the ground at each end (with the ends taped up). I can plumb it up to anything.

I haven't even bought the tanks yet - I was going to go with 2 layers of 3 tanks all plumbed together.

The only rule is that it can't be stupidly expensive as we are already way over budget and just trying to save some water.

I can take a picture tomorrow, but it looks just like any other pipe stuck out of the ground you've ever seen.

 
I use one of the Clarke booster pumps (from Machine Mart, not too expensive,) to take water from my well up to my water header tank in the house, it is controlled by pressure so when the header tank is full the ball cock closes and causes the pressure switch on the pump to switch it off.  Pressure works between 1 and 3 bar if my memory is correct.

Pumps switches off at 3 bar.

Pump switches on at 1 bar.

Well water level is about 2 meters below pump, suction pipe has a foot valve on it so once primed it's done.

Deliver side from pump up to header tank is about a 40 meters run climbing about 9 meters.

System works great, Only had a problem once and that was about 4 or 5 years ago during that long frosty winter, I got frost damage to pump casing, won't happen now as I have trace heated it on a frost stat.

Just a different idea that is easy to install and maintain.

 
Canoeboy said:
Ill price up monday for you - with a submersible - you'll need two floats, one in the suction tank and one in the header tank
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Thank you

I'm not seeing why I need one in the supply tank? They should always be full of water?

Could I use what I linked in #28? On and off in the header tank would be my preference.

 
I'd look at a pump with a pres control and a small reservoir tank to reduce cycling at the outside shed and install a good old fashioned ball float valve in the tank in the roof. The pres control will monitor phase angle to give you dry run protection as well as run current to give you overload protection, It also controls pump on/off and In this type of system it's the easiest, all in one small package with easy installation and no external control cabling., it avoids fragmented controls with level sensing in the top tank for on/off, level sensing in the bottom tank for dry run protection plus thermal overload for run current protection.

The setup would look something like this;pump with pres control.jpg

And yeah, you can't self prime more than 10 meters on the suction side without using jiggerypokery like venturi systems or back-prime water injection

 
The pump above is the one I have, use to have the one in Marvos picture but found the one above better as it cycles less due to the bigger tank with pressurised bladder in it.

 
Marvo said:
^^ This would still require dry run protection in the bottom tank, level control in the top tank and separate motor overload protection.
Click to expand...
Level control is done by the ball cock on the header tank closing, causing the pressure to rise and shut off.

Dry run protection ( and burst main discharge pipe) is not mentioned in the manual from what I remembered but I added it myself by adding a timer that shuts the system down if it ever runs for more than 90 seconds, this works because if everything is healthy the pump will never run for 90 secs even with the ball cock full open. It would stop for about a minute and then start again, the fact the motor stops resets my timer.

The booster pump is just supplied with a 13 amp plug so only basic motor protection.

 
if you are just using a pressure washer, you may nit need the header tank at all, the latest karcher range can work off a water barell. so if you mountd the ground tanks on a few breeze blocks it may well work absolutely fine anyway??

A customer of mine was using an electric hand drill and pump attachment to pump water up 2 storeys to his loft, just as an opinion, and in no way meant as a criticism, some of the proposed solutions are rather overkill?

 
binky said:
if you are just using a pressure washer, you may nit need the header tank at all, the latest karcher range can work off a water barell. so if you mountd the ground tanks on a few breeze blocks it may well work absolutely fine anyway??

A customer of mine was using an electric hand drill and pump attachment to pump water up 2 storeys to his loft, just as an opinion, and in no way meant as a criticism, some of the proposed solutions are rather overkill?
Click to expand...


I concur.

My karcher runs fine off FA pressure and I note the local car washers also use a tank rather than a tap.

http://www.screwfix.com/p/titan-ttb582pmp-400w-automatic-dirty-water-pump-240v/65041

:C

:)

 

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