Mysterious pipe on toilet... help!

[Lextek]

Hello. I have just moved into a new flat and was going to replace the toilet today when we found that the old toilet has an extra pipe going on the soil pipe... it tees off of the waste pipe behind the toilet and then enters the soil/stack pipe a few feet away... anyone know what this is for please? Thanks.

 

[glasgowgas]

View media item 11886

 

[kirkgas]

sounds like a vent pipe

 

[dextrous]

sounds like a vent pipe

does, doesn't it.

 

[Lextek]

What do you think would happen if I got rid of it?

 

[sooey]

What do you think would happen if I got rid of it?

If someone in another flat flushes while you're on the throne you'll get sucked in.

 

[dextrous]

Without knowing more, hard to guess.

 

[Lextek]

Thanks for your replies...

I just don't undertstand what it coulp possibly do? There is already a soil pipe which is vented through the roof, all this pipe does is loop off of it... what could possibly be different about this system that it requires an extra vent pipe?

 

[kirkgas]

the extra vent might be there to allow your loo to work when others are flushed at the same time, if others are flushed your loo might not have a vent as the soil pipe is full of water, therefore you have an extra vent, (but it is late so this theory could be way off the mark, but luckily enough there will be plenty of people quick enough to advise me i am wrong )

 

[doitall]

I assume the waste pipe feeds the bath/shower or both.

The pipe sounds like an anti-siphon vent, normal practice in older properties.

 

[Nige F]

What do you think would happen if I got rid of it?

Not a lot Bit like the Forth Bridge , if it was built now it would be a lot " lighter"...just old fashioned stuff. If you really wanted to you could fit a pan connector with a 1/14 inch boss and pop a small air admit valve on it That would do the same job and allow all the old pipe in the flat to be removed. Plug off the redundant vent end too

 

[doitall]

The vent is almost certainly for the bath/basin.shower, or something on the smaller waste pipe.

A pic or more info would help, but you can bet it's there for a purpose.

 

[Nige F]

Thanks for your replies...

I just don't undertstand what it coulp possibly do? There is already a soil pipe which is vented through the roof, all this pipe does is loop off of it... what could possibly be different about this system that it requires an extra vent pipe?

It`s archaic . Please send a pic, or there will be 6 pages of debate about this too IF you happen to be in Eastbourne -I see you`re in Sussex. There is a classic example of this old pipework on the garage building near Whitley Road railway bridge. You might want to look @ the new cars for sale while you`re there too

 

[kevplumb]

 

[Onetap]

I assume the waste pipe feeds the bath/shower or both.

The pipe sounds like an anti-siphon vent, normal practice in older properties.

It was called a puff pipe, it was intended to prevent the water seal in the trap being sucked out by the flushing of a WC on another floor connected to the same soil stack. They were common before the modern single stack soil and vent pipe came into use. They are often seen on drain stacks on the back of old buildings.

PS I nearly added that vented drains are still used in the USA, but I see our colonial friend has posted a picture of their antiquated plumbing. Thanks, Kev.