Manual 2-way valve for rainwater system?

[Paulh_Boats]

Where can I buy a manual 2-way valve, to fit 15mm?

I want to switch between mains water or rain water to fill a cistern. In electrics its 2-way, but I think in plumbing speak its got 3 ends so its 3-way!! 

cheers
Paul

[Greenbeast]

could you not fit a modified ballcock so that if there isn't enough rain water it refill with mains
you could then just fit a normal vavle on the rainwater pipe if you wanted to stop the supply

something like the pic on the second page of this pdf:
http://www.alternativetechnology.info/rainwater_recycling.pdf

just an idea

[Antman]

Where can I buy a manual 2-way valve, to fit 15mm?

I want to switch between mains water or rain water to fill a cistern. In electrics its 2-way, but I think in plumbing speak its got 3 ends so its 3-way!! 

cheers
Paul

Paul

I think you want an L-port valve but they're not cheap.

The cheapest RS do a 1/2"bsp  L-port 328-4908 at £23.79 + Chancellor's bonus. Plus you need thread adaptors to 15mm.

Antman

[Paulh_Boats]

Greenbeast,

Thanks for the link, but I'm trying to create a pump-free system that uses gravity to fill the downstairs loo by raising the tank above the cistern.

The plan is that we manually switch to mains feed if the rainwater tank is empty. I might just prototype it with a check valve in the mains and 2 washing machine valves for 99p each! For the rainwater tank my thoughts are to use a 400L tank.


Or maybe I should just go for the automatic loft pumped system? Not sure about power consumption etc..

cheers
Paul

[Eleanor]

Paul, no doubt a big box of fittings but not the one you want, something I am very familiar with. I wonder if it is wise to have rainwater and mains water in contact in the valve and the potential cross contamination issues  . The water company wouldn't approve  . Perhaps I have misunderstood 

[northern installer]

happy friday everyone....I came up against the possible problem of cross contamination when designing my rain water system;simple solution,bring both grey and clean supplies side by side(in my case under toilet cisterns) and terminate each in a ball isolating valve..98p each.from the cistern,take a flexible tap connector,and simply connect to whichever service you are using.Cheap,simple,and no cross contamination!

[Greenbeast]

paul how is the water going to be collected?


however you get the water there, the tank and ballcock idea does mean no cross contamination and no manual switching, if there's not enough rain the mains will keep a certain amount of water in the tank

[Paulh_Boats]

paul how is the water going to be collected?

however you get the water there, the tank and ballcock idea does mean no cross contamination and no manual switching, if there's not enough rain the mains will keep a certain amount of water in the tank

Well its gonna fall out of the sky  .. then diverted from the roof downpipe.

Regarding the cross-contamination, the water byelaws insist on a double check valve (one-way valve) in the mains feed if there is "significant risk to health" which I will most definatly fit whatever the final solution.  Not sure about the need to isolate beyond that, but thanks to everyone for highlighting the issue.

[Greenbeast]

what i meant is how are you getting it from the gutter to the tank?
is this a tank in the loft? or is your toilet below the level of a water butt?

[Paulh_Boats]

Greenbeast,

The downpipe for half the roof (25m2) is 4m horizontally from the downstairs loo. Next to the downpipe is an average round water butt fed from a divertor....there is space to put in a larger rectangular tank also.

I could raise the water butt 75cm above the ground and if connected to the cistern most of it would fill the cistern via gravity. Well thats the plan 


-Paul

[Greenbeast]

right i see

that makes it a bit awkward for my idea mainly because of the likely hood of the mains backup line freezing in winter.
other than that there's no reason why you could use the idea inside the butt instead of a roof tank

[Paulh_Boats]

Greenbeast,

Good point about the freezing. One idea is to add pipe insulation and send the pipe immediatly into the house so only a foot or so is outside. Then I can route the pipe along under a radiator then through the internal wall to the downstairs loo.

Paul

[Greenbeast]

yeah so if you have a mains backup pipe and a toilet feed pipe, insulate and keep the runs short and you'll hopefully be alright, i don't really know for sure

[Watermann]

Similar design to mentioned here but have hit a problem. I want to use rainwater to flush a downstairs loo. I started by looking at all sorts of 3 way valves but came up with a much better answer at the design stage.

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.

However, during install I've hit a problem. The side entry valves I've tried so far - made by Fluidmaster and Wirquin need significant water pressure to work - certainly more water pressure than I have, the storage tank is only a metre or so above the loo. A traditional ballcock controlled valve does work but there is not enough room for that without some serious modifications.

Has anyone found a side entry float valve that works at very low pressure ? There are a few more makes I can try but would be good to have a clue about one that might work before I have to mess about trying to get a ballcock in the cistern.

[mespilus]

However, during install I've hit a problem. The side entry valves I've tried so far - made by Fluidmaster and Wirquin need significant water pressure to work - certainly more water pressure than I have, the storage tank is only a metre or so above the loo. A traditional ballcock controlled valve does work but there is not enough room for that without some serious modifications.

Has anyone found a side entry float valve that works at very low pressure ? There are a few more makes I can try but would be good to have a clue about one that might work before I have to mess about trying to get a ballcock in the cistern.

Hi,
haven't got the details in front of me, but if Fluidmaster are the firm with a UK agent in Bristol, phone the very helpful customer services,
explain what you are upto, and they can send you a more flexible valve.
This works with a lower head of water pressure