Cistern overflow connection?

[Buk]

Hi,

The connector between the bottom of the overflow tank connector and the 21.5mm pipe that goes through the wall has broken.

That is, the "nut" -- a round piece of threaded plastic with ridges rather than flats -- sheared radially between the internally threaded part and what appears to be a internaally tapered part of the "nut". This happened whilst *undoing* it. (And yes, I am very confident I was undoing it.)

Anyway. The problem I have is what is that "nut" called? Ie. What do I search for to purchase a new one?

In addition: How does it work? The pipe has no kind of furrel on it. How does it make a seal? Was it glued? (It was certainly very tight before it sheared.)

(link to offsite image if the embedded image does not show up below

https://imgur.com/fSIWN3O

)

In the image below, the grey at the top, is the bottom of the tank connector from the bottom of the cistern. The overflow standpipe is attached to it inside the cistern.
The pale yellow at the bottom is the 21.5mm pipe that takes the overflow outside.
The green is the weird ribbed nit that sheared; and the blue dotted line is where it sheared.

Help?

 

[Madrab]

It is simply that, the overflow coupler to connect the overflow from the cistern to the overflow pipe. It doesn't need any seal per sé as it's very low pressure/flow and would only really weep if at all, so wouldn't really need a seal.

You would probably need a new overflow dip tube -

 

[Exedon]

Just buy a complete new overflow

 

[Buk]

It is simply that, the overflow coupler to connect the overflow from the cistern to the overflow pipe. It doesn't need any seal per sé as it's very low pressure/flow and would only really weep if at all, so wouldn't really need a seal.

You would probably need a new overflow dip tube -

View attachment 325875

Okay. Thanks.

I found this overflow standpipe at Wickes which does show that ribbed nut. No mention of a sealing ring, but I have o-rings that'll do the job (even if it isn't strictly necessary

The standpipe is a fixed length. Presumably I just cut the top off to match my cistern?

 

[Buk]

Just buy a complete new overflow

Now I know the ribbed nut is a part of that, that makes sense. Till now, I thought the standpipe was just a bit of pipe and a tank connector; which wouldn't have that extra nut.