Siphons

[TheBigMatt]

Hi All,

Ok, i think my tired dusty brain has finally figured this out....

If the water level in a WC Cistern is higher than the top of the Siphon, then the water will flow down into the WC..Yes?? (unless it comes out of the handle hole etc.)

So if i want to put in a new Toilet and do away with an External overflow pipe, i can just fit a shorter siphon?? OK, i guess the siphon has to be tall enough to give a good enough level of water etc.

If that's the case, what are all the special siphons with "Internal Overflows" all about.

Advice appreciated.

Matt

 

[wonderb0y]

If the water level in a WC Cistern is higher than the top of the Siphon, then the water will flow down into the WC..Yes?? (unless it comes out of the handle hole etc.)

No it should go into the overflow pipe and drain outside, before it reaches the handle.

So if i want to put in a new Toilet and do away with an External overflow pipe, i can just fit a shorter siphon?? OK, i guess the siphon has to be tall enough to give a good enough level of water etc.

You can just fit a siphon with an internal overflow in a new toilet and set it to flush on full at 6 litres.

If that's the case, what are all the special siphons with "Internal Overflows" all about.

to do away with having pipe coming out of your wall..

 

[TheBigMatt]

Hi Wonderboy,

What i don't understand is this. I go look at a siphon that say's it has an internal overflow, it looks the same as any other siphon i have ever looked at. Wheres the water go??

Now, if there was a big hole down the middle or something, i could understand it.

I looked at a siphon called a dudley 88 turbo (or something like that), now it had a small hole in the top of the siphon, hardly big enough to call it an overflow.

Is that hole for water?? or does it let air out of the top of the siphon so that the water inside the leg of the siphon can rise with the cistern level and overflow down the "flush" leg??

Perhaps i am not explaining myself well, but i dont want to put in a siphon that say's it has Internal Overflow without being sure how it works, especially if i am going to remove the external overflow pipe.

cheers for the reply anyway.

Matt

 

[wonderb0y]

does this make it any easier?

http://home.howstuffworks.com/toilet4.htm

you cant always see the internal overflow, just check the packet to check it does have one built in.

and on the dudley it tells you on here how the internal siphon works at the bottom of the page http://www.thomasdudley.co.uk/pdf/turbo2.pdf

 

[Softus]

If the water level in a WC Cistern is higher than the top of the Siphon, then the water will flow down into the WC..Yes?

Yes.

...(unless it comes out of the handle hole etc.)

Correct.

So if i want to put in a new Toilet and do away with an External overflow pipe, i can just fit a shorter siphon?

Yes, but you've already spotted the pitfall...

OK, i guess the siphon has to be tall enough to give a good enough level of water etc.

Yes.

If that's the case, what are all the special siphons with "Internal Overflows" all about.

What "special" siphon are you referring to?

you cant always see the internal overflow, just check the packet to check it does have one built in.

All siphons will overflow internally when the water level reaches the level at which they overflow internally.

 

[TheBigMatt]

Hi WonderBoy,

Thanks for the Links, the Dudley link explains a lot.


Softus,

Thanks for confirming what i thought. The siphons i am talking about are advertised as "internal overflow" but look just like a "normal" one.

A "normal" siphon looks like it would trap air at the top and prevent the water rising to an overflow level. Perhaps the siphons that advertise as being internal overflow have the up and down legs join at a lower level.

I guess i will just buy one that say's internal overflow and stick it in, hopefully when i test it i won't get wet feet.......


cheers Matt