[Closed] Plumber: diverters, taps and valves...

Could you use a diverter valve plumbed in reverse with two non return valves to prevent back flow?

I was thinking similarly, but cant find a suitable diverter valve (non motorised) - can you find any links?

The alternative is just to use two inline lever ball valves with two non-return valves. Just means you have to remember to have at least one supply valve open to have an output...

on the same subject, I have found this:

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which would be used in the collection circuit of a greywater system

The supply side is where I want a diverter to select between recovered water (from header tank) and mains water supply to toilet cisterns.

this is pretty much the syetms I had designed in my head...I shall read on! 🙂

http://www.reuk.co.uk/Rainwater-Toilet-Flush-System.htm

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I found this http://uk.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=0486328

cheers snaps, the 3way L port looks right.

Of course it wouldnt be needed if I were to use a control board on a dual supply header tank though....

Since I need a pump with float switch operation anyway, Im going to need a control board, so might as well go straight for that system rather than a diverter at the cistern end....

The other system I've thought of needs two ballcock valves in the cistern, one from the rainwater tank & the other from the main but with a http://www.cistermiser.co.uk/index_c.aspx time delay unit inline so if the refill dosen't happen from rainwater within 15 minutes the mains fills it.
I've also seen a system that uses a floatswitch controlled solar pump to send water to a tank higher than all cisterns so they can be gravity fed.

ALl of these systems though require at least 2 tanks - one at ground level (filtration/collection) and another as a header that feeds the cisterns.

It would be nice to pump directly from the lower tank to the cistern controlled say by a pressure switch and non return valve - so a pump pressurises the greywater supply, but when the pressure in the supply falls (say when a cistern ball cock valve opens) then a 12v pump pumps away until the cistern valve closes and the supply is under pressure again...

Im betting that's a stupid idea though 🙂

brass hosepipe splitter

apparently

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Using the solar system, you have zero running costs once installed - the pump can be tiny, the one I saw only had 6mm pipes on it & the tank in the attic held enough water for 6 flushes & could be filled in less than two hours average daylight.

I don't know how far along with the design you are, but could the system not be simplified by putting the rainwater collection/holding tank above the level of the cisterns like the 4000l one in my house? We just have an extra bit of loft space for it in the return above the kitchen/scullery. Those Victorians worked a fair few things out before they needed relay boards and electric pumps.

I was more going to use receyled greywater, however, Im not wholly happy having to treat it with bleech to prevent it going septic. Having read more about the greywater storage on that website (max 1 day without treating).

I think what I might do to simplify is just rig a tank to the downstairs cistern which can be filled with rainwater and then use a splitter tap like my pic above to manually switch between mains and rainwater feed.

I see, yes greywater can easily get smelly. One approach can be to have a taller header tank with two float valves set at different heights. You set the height difference so there is just more than a cistern worth of volume difference between the (lower) mains water and the (upper) rainwater feed. If the rainwater tank is empty, the mains will keep the header full enough. You need a check valve in the mains feed to avoid contamination if you get backflow or siphoning through a busted floatvalve. No need for diverter valves this way. Flushless loos not an option then?

Flushless loos not an option then?

I can dig a hole in the ground as well as the next man, but Im not sure the missus would be up for it 🙂