Manual 2-way valve for rainwater system?

[solar_cambridge]

Most modern cisterns have a side entry fill valve and the plastic cistern allows for this to be fitted left or right. so the answer is you fit two - there is enough space in the MacDee cistern I'm using.

The one on the left connected to the mains, the one on the right connected to rainwater. The one on the left has an isolation tap that is easy to reach and operate and is normally turned off.

The one on the right is connected to rainwater. If rainwater runs out the family know to turn on the mains isolation tap to allow the loo to flush. As soon as it rains again and the tanks fill then tap is turned off and it's back to rain water to fill, all good on paper.

You can't do that and meet the water regulations - I know as I've just done the course. You need an air gap from any drinking water source going into a tank that contains Fluid category 5 (the nasty stuff). A double check valve isn't acceptable.

I'm working through a system design atm, so currently thinking through viable solutions myself.

In your situation, the only option would be to put the inlet from the mains ballvalve above the top of the cistern. So the cistern itself would overflow rather than contaminated water touching the mains inlet point.

[Paulh_Boats]

Most modern cisterns have a side entry fill valve and the plastic cistern allows for this to be fitted left or right. so the answer is you fit two - there is enough space in the MacDee cistern I'm using.

You can't do that and meet the water regulations - I know as I've just done the course. You need an air gap from any drinking water source going into a tank that contains Fluid category 5 (the nasty stuff). A double check valve isn't acceptable.

I'm working through a system design atm, so currently thinking through viable solutions myself.

In your situation, the only option would be to put the inlet from the mains ballvalve above the top of the cistern. So the cistern itself would overflow rather than contaminated water touching the mains inlet point.

In that case a good solution for both upstairs and downstairs loos is the header tank design, as per an earlier post; with bent mains ballcock feeding the lower 3in only, pumped rainwater via float switch for next 6in then an overflow well below the mains feed:

http://www.alternativetechnology.info/rainwater_recycling.pdf

[solar_cambridge]

In that case a good solution for both upstairs and downstairs loos is the header tank design, as per an earlier post; with bent mains ballcock feeding the lower 3in only, pumped rainwater via float switch for next 6in then an overflow well below the mains feed:

http://www.alternativetechnology.info/rainwater_recycling.pdf

That design contravenes water regs too for the same reason. Ballvalve is inside the cistern itself. I ought to send them an email and let them know 

[Nick.Winn]

You must protect the mains water from contamination. Your rainwater in the tank will probably be a fluid category 4, but if there is any likelyhood of contamination by, say, bird droppings on the collection roof, this may take it to category 5. A ball valve on the rainwater tank so that the valve opens when the water level is low in the tank, will give adequate backflow protection, automtic change-over and consume no power. Although the ball float will be low in the tank, the valve must be at the top maintaining an adequate air gap between the valve and the water surface at all times and ther must also be an overflow on the tank to ensure this. Additionaly you must be able to see water running if the ball valve fails. ie if you divert your rainwater downpipe into the tank to collect water, and have a length of downpipe from the tank back to the gulley, you must break this with a hopper so that you can see the water running. (water running on a dry day = leaking ball valve!).I  would go belt and braces and fit a double check valve on the supply to the ball valve.

[fox]

Been using a rainwater system for a WC/Washing machine for several years. Pipework is 22mm up to the house where it is reduced to 15mm. (a work in progress shot. Now insulated and re-pointed).



....then underfloor and up where it joins with the WC into a T-Piece and two full bore 15mm gate valves.



No contamination as the rainwater tank is below the loft tank. WC is fed by a separate branch from the loft tank. Connecting a Washing Machine means branching into drinking water pipes -- so a double-stop valve goes where the two meet.



I've a private spring (needing processing before it can be potable), and its crazy to put drinking water into a WC.



Here's 4 months filtering. I've tests every 6. I now filter from 100µ down to 1µ to be sure.

[David]

http://www.alternativetechnology.info/rainwater_recycling.pdf

That design contravenes water regs too for the same reason. Ballvalve is inside the cistern itself. I ought to send them an email and let them know 

Provided the warning pipe is adequate and in the right place there should always be a suitable air gap between the bottom of the ball valve and the surface of the water. The weedy 22mm warning pipes used down south are certainly not adequate, but the 40 mm one on my cold water tank is more than capable with coping with mains pressure water from a 22mm inlet pipe (I have tested it). However, you have provided some useful information which I have noted.

[10sheds]

Hi I've been frustrated by low pressure valves on my rainwater flush toilet for the past five years have a fliudmaster now the best but not perfect. Keep thinking about experimenting with the ball out of a deodorant bottle but like so many things it sits on the shelf waiting

[Mike N.]

experimenting with the ball out of a deodorant bottle ...

Reading that gave me a quick flashback to the sketch on Not the Nine o clock News in the Swedish chemist shop:
"I'd like a deodorant please."

"Ball or aerosol?"

"Neither, it's for my armpits."

Mike

[lightfoot]

experimenting with the ball out of a deodorant bottle ...

Reading that gave me a quick flashback to the sketch on Not the Nine o clock News in the Swedish chemist shop:
"I'd like a deodorant please."

"Ball or aerosol?"

"Neither, it's for my armpits."

Mike

 

Someone help me up off the floor.......it's good to start the day with a belly laugh

Cheer's

Lightfoot.

[solar_cambridge]

Been using a rainwater system for a WC/Washing machine for several years. Pipework is 22mm up to the house where
....then underfloor and up where it joins with the WC into a T-Piece and two full bore 15mm gate valves.

I think what you are saying is that you can change over the WC supply from rainwater or potable depending on availability of rainwater and that your WC is tank fed. If you are on your own private supply then regs don't apply, but I'd still say they are worth following to save yourself the potential of drinking rainwater...

At the very least remove the permanent link to your potable supply so that its impossible to open both valves and mix water types.  Put some labels on the rainwater pipework indicating it is 'Rainwater'.

[petertc]

I don't know if yu have done this yet, but it is a bit of a no no.

you must have a air gap between the mains water and any non potable water. this is all part of the water regulations.

I used to work for a company that did private water supply, and having to explain to people once they went on to there system you could not just reconnect to the mains supply if there was a problem.

The only way of doing this was a storage tank that the water was stored in then pumped  of gravitated to the system. in the event of a failure then the mains water could fill the tank but the valve had to be mounted above the tank so that if the tank over flowed there could be no way of the water getting into the mains system if there even if there were a mains failure. It's all to do with back back siphoning.

[fox]

At the very least remove the permanent link to your potable supply so that its impossible to open both valves and mix water types.  Put some labels on the rainwater pipework indicating it is 'Rainwater'.

In the end I noticed we were using 100% rainwater so I unhooked the potable feed. Pipe connection is still there -- just in case but only the rainwater is physically connected. Both feeds now come with a double flow valve fitted so neither systems can mix.

[matt_w]

Could you use two tanks for the loo with a Y shaped T on the feed to the pan?  Would that pass?  I like the idea of a couple of victorian style high wall mounted tanks, the extra hieght helps give a bit more oomph for tricky situations ;-)

Matthew

[pontiff]

After reading the link below I came to the conclusion that the only option for my rainwater " feed the downstairs bog system" was to completely disconnect from the mains and reconnect via a pushfit if the water ran out, froze etc. Type AA or AB airgaps are required to keep the water police at bay.  Pity, as I thought my dual intake toilet was a winner!

http://www.keraflo.co.uk/downloads/water-regulations.pdf

[Baz]

Matt,
how about a low level cistern fed by rainwater, then a high level standard supply one whose output feeds not to the pan but to the low cistern through a pipe system possibly incorporating another free air gap. When the rain runs out a double flush is required, from high to low, then onward.