syphonic double trap toilet.

[spooney54]

hi there,
Im wanting to get a better understading of how the syphonic double trap
toilet works.
I.E how the negative pressure between the two traps comes about?
How exactly does the aspirator bomb operate?
Are there any web site that may show sketches,or give explanation, etc?
I may have one to repair.
Any advice appreciated. thank you.

 

[charliejamesuk]

Tiny bit of info here:
Types Of WC Pan - SimplifyDIY - DIY and Home Improvement Solutions

Think they are more common in Europe.

 

[spooney54]

Thanks for info. cj uk. Still would Like more detailed info about the action of the aspirator bomb if possible.

 

[johnmcginty]

First of all if they are broken it will look like a blocked loo, so look at the trap and see if it is syphonic , it will be visibly higher up and when flushed the water will appear to be sucked out like on a plane. This is because water is going down the second chamber and out down the soil pipe, as this happens it syphonically sucks the water and waste out of the first visible trap. water then fills up the first trap from behind and the front. if you need to fix one nowadays you need a turbo 88 syphon and a syvac aspirator or replacement washer both are available from toolstation. Can be a bit of a ball ache, make sure the washer on the bottom of the aspirator gets pushed up the spout slowly when you are putting the cistern back on.

 

[spooney54]

Thanks a lot leedsplumber.The problem seems there is only very light suction there,but the toilet eventually clears. I have bee told it could just be a worn seal at the bottom of the aspirator.Are these seals available on there own?

 

[johnmcginty]

Yes mate it is called an aspirator washer just pop out the cistern and swap it over like I said though pop it on and slowly lower the cistern back on doughnut. As you will see from the picture you can see why it is caled a bomb as looks like an atom bomb
Toolstation > Plumbing > Toilet Fittings > Syvac Washer

 

[Phil]

Interesting,

Just out of interest John, why would you need to use a Dudley turbo 88 syphon and not a normal one?

Any syphonic toilets I rip out I always keep the cistern guts for spares but I will use a new turbo 88 if they would work.

Is it because the aspirator fits into the bottom on an 88?

 

[TGor]

hi there,
Im wanting to get a better understading of how the syphonic double trap
toilet works.
I.E how the negative pressure between the two traps comes about?
How exactly does the aspirator bomb operate?
Are there any web site that may show sketches,or give explanation, etc?
I may have one to repair.
Any advice appreciated. thank you.

The negative pressure between the 2 water seals is caused by the aspirator which as the name implies sucks out the air from the space between the two traps . The aspirator is a venturi device which as the water from the flush goes through it sucks out the air causing reduced pressure. so id the seal is damage it will not work. There are other types of siphonic pan which have a smaller diameter outlet which creates a siphon effect (self-siphonage)

 

[johnmcginty]

Interesting,

Just out of interest John, why would you need to use a Dudley turbo 88 syphon and not a normal one?

Any syphonic toilets I rip out I always keep the cistern guts for spares but I will use a new turbo 88 if they would work.

Is it because the aspirator fits into the bottom on an 88?

Thats exactly it yes it wont fit into a normal one like an opella , I think that one anyway is made by the same company .

 

[Phil]

Thanks for that John.