Float valve for the mains top system in my header tank

[AV1]

I am looking for a float valve to run my top up system within my header tank...my thoughts are that a low pressure ball valve will not like being set under water all it's life and I need to source another float system. Anyone done this or can point me in the right direction. TIA
Adrian

[Justme]

Cant you use one with a longer arm to hold the ball under whilst keeping the valve out of the water?

How deep does it need to be?

[AV1]

It is has 18 litre capacity tank with a liquid float switched pump (complete with a weir) that I want this top up main float system to only work if the water is below 10 litres, so I need the body of the float valve to be at the plus 18 litre but floated to 10....this would mean that a long arm would be held hard below the surface water as a permanent feature.
Adrian

[Baz]

Normally a ball float stops the valve with about 25% submerged. If it gets fully submerged it will as you fear stress both the valve rubber and the wall of the tank. However if you get a unit with a brass arm and bend it down to reach the low level the moment of the lever about its pivot will be reduced to an acceptable level.

[AV1]

Moving this on ..I thought that a standard torbeck valve with a stainless steel 2ba threaded bar with locking nuts to attach it to the float swing arm (to give adjustment) and melt some wax to create a bespoke float on the end of the bar (again a couple of nuts and washers within the wax part to ensure attachment) that I will I can then shave down to the point that I get the correct  pressure on the valve.....any thoughts, views, etc.
Adrian

[fatbob]

Hi Adrian,

I think I get the hang of where you're coming from about the torbeck valve, by recreating a longer stick for the 'float on a vertical stick' arrangement that they have, but I'm not sure whether wax would have enough buoyancy to support the steel bar, nuts and washers and maintain firm enough force on the lever arm to keep the valve closed ?  If this were me I'd try to fit the steel bar to the existing torbeck float end to achieve the same thing perhaps ?

The theory seems sound enough to me, there's only one sure way to find out 

Cheers,  Bob.

[AV1]

Thanks for your thoughts on this Bob, I have moved this forward a little today and changed from S/S to brass, as I already use the 2ba threaded bar as + and - posts through the body shell on my fibreglass cars ....My thoughts on the wax was that as this will be under water by 6-8 inches I can work out some kind of similar loading against the valve and crank it too, if I need to. Adrian

[AV1]

An update...2 float valves cropped and extended with a little piece of tube...and a limit stop using the ball pivot, the side wall of the 4 gallon tank braced.
Adrian@

[Brian-s]

As the float would normally be only 25% submerged. (This is a guess.) You could drill a hole in the float and partly fill it with water so it does not have as much lift. When you have the right amount in you can re seal the hole. Bend the float arm to keep the valve out of the water. This will avoid contamination of the mains water although you should have a non-return valve as well.

Brian.

[AV1]

For anyone who's interested ..I'M pleased...Today...killed the mains supply to the 2 toilets..I had previously killed the mains to the downstairs toilet and connected this to a T piece next to the upstairs toilet, then I fed a new mains supply to the new header tank and a drain from the header to T into the disconnected 2 toilets. I had previously created a break tank and tray with overflow ...installation complete! I am in test mode and manually holding the float down after using the toilets and simulating a full level test (raising the water level to the electrical float valve level that will complete the circuit and pump the rain water from the external ground floor tank). The current levels in the tank allow 2 full flushes (as opposed to 1/2 flushes) before the mains top-up float takes over to top the system up, also given that when the pumped rain water system is running AND there are only 3 of us living in the house, this will most likely beat the valve operation in filling again, before the mains top-up gets chance to do anything. I am well pleased, a long time coming BUT as my first priority in life is to keep my profoundly deaf 6 year old talking and listening like a 7 year old! (his last tests come up with 6 years and 11 months...I better get back to work!). Adrian@

[fatbob]

Hi Adrian,

Great to hear you're making progress, sounds like you're well on the way to getting your system fully up and running.  From to your description, it sounds like you have (or will) run a signal cable from the loft tank float switch to the downstairs tank to activate the pump.

I'm nowhere near getting a toilet top up system running, but currently considering the pros and cons of float switch control in the tanks vs a pressure activated pump.  Can't say I've come to a definite conclusion to what's best.  The idea of fewer cables/pipes to run throught the house appeals to me, but there again as I'd be installing a water pipe on the same run, it wouldn't that much more work to run a signal cable with it at the same time.

Has anyone else got any thoughts on the two options ?  Are there any pump/control options that I've not though of ?

Cheers,  Bob.

[trubble]

I'm working on my 'system' this week - have gone for the pressure switch option and just ordered a "GP73PE31.000 PRESSURE SWITCH RANGED 0.1 TO 5.0 BAR"
- catchy name - from ebay. Not cheap at £35 inc postage, but on the basis I just picked up 20+ lengths of solvent weld pipe for a fiver, I though I should push the boat out
I've got 2 x IBCs under the floor (big void!) with 2 x large-ish interlinked black plastic header tanks in the loft - pumped rainwater in via a standard ballfloat and valve, then gravity feed to wcs and outside tap.
To minimise cable routing, the pressure switch seems easiest as it is close to the pump - switch is adjustable and has three terminals so can be NO or NC.
So I'll have a blue Machinemart bilge-type pump in one IBC, with a non-return valve just upstream of it.
Then the pressure switch and also a 12 litre expansion vessel in the line up to the ballfloat, which will hopefully even out any bangs or phantom pumping.

Here's hoping....

[Baz]

I have been wondering if there is any need to use anything larger than 8mm pipe for plumbing as there isn't a rush to fill the cistern. Comments?

Secondly I have considered a dual direction pipe as follows. Pump feeds pipe to toilet cistern ball valve then on up to attic where a T goes to the normal float valve and the other branch joins through a non return valve (oriented outflow only) into the base of the tank.   Pressure switch at pump stops it when all floats stop flow. The idea of the non return valve is to let water back down that route when the pump is off thus only needing one pipe, no wires. The tank to hold say a days use and pump supply  on timer to run off E7 or solar. Comments? Biggest danger seems to be dirty water making valve leak.

[Justme]

I assume that you will be using a pressure controlled sensor to trigger the pump on & off for tank filling. If so then the pipe will stay pressured & so hold the one way valve closed against the very low pressure of the standing water in the tank. A flow sensor would not work as there would be no flow without standing pressure (which you cant have or the one way valve cant open) when the ball vale opens.

[Iain]

Hi Baz
http://uk.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=7259931
I use one of these to switch on my pump to fill my header tank. I just have it switching the pump via a relay. Has worked lovely for a few years, no problems. Would allow your non return valve system to work (without the non return valve!!!), but you wouldn't need the float valve in the header tank. Just have the inlet/outlet about 2" up from the bottom of the tank.

Also use one of these for one of my other transfer pumps
http://www.machinemart.co.uk/shop/product/details/float-switch-230v-2m-cable
Again no problems.
My system, has been improved/modified a bit since the post,but generally the same
http://www.navitron.org.uk/forum/index.php/topic,2960.0.html
Iain