How to connect brass compression fitting to plastic thread

[paull123]

Hi
Can anyone please advise a foolproof way of making a once only watertight fitting connecting a 15mm brass compression fitting on to a plastic threaded connection on the waterfill on a toilet. The water is mains supply. Because of the lack of space around the toilet I can only make this connection once with no tightening the joint afterwards as I have to then work backwards to refit the toilet from this connection. Would you use PTFE or a sealant in the joint?
Thanks

 

[seco services]

you mean fit a service valve to the toilet fill valve. ?

use a new fibre washer no sealant, screw on by hand, just give it a nip up with adjustables.

 

[mysteryman]

You would be better to use a plastic pushfit straight tap connector or servicing valve on the tail, and then push copper pipe into it.

 

[m1key00]

you need a 1/2 " tap connector and fibre washer, you can get these with compression to the 15mm, some would say dont use sealant on plastic, but I would be inclined to use a bit of LSX sealant or Plumba sealant if I wanted to be double sure,

Or...have you thought about a flexi connection? these come with a rubber washer to seal against the plastic and very rarely leak, you could get a push fit version to get you back onto the 15mm if you are not confident.

 

[m1key00]

three replies at the same time, is this a record, have we not got beds to go to?

 

[seco services]

Because of the lack of space around the toilet I can only make this connection once with no tightening the joint afterwards as I have to then work backwards to refit the toilet from this connection.

why is it that bad you have to fit the valve before install ?
sod's law that fill valves gonna need changing oneday.

 

[paull123]

Its the worlds smallest toilet, I only have an 8" gap on the side to work round !!

 

[Gasop]

three replies at the same time, is this a record, have we not got beds to go to?

Beds or cots? How old are you?

 

[TicklyT]

Whatever you decide to use, you can't fit an olive and nut from a compression fitting directly to the plastic tail of the fill valve, which appears to be what you want to do.

The end of the valve is not shaped to accept an olive, and the threads will strip before you get it tight enough to seal.

The fill valve is designed to fit onto a tap connector. There are many forms available, including soldered end feed (probably the most compact), compression, push-fit and braided flexible hoses.

Many are available with a service valve incorporated into the connector. These tend to be a bit bulkier.

Most are available in either straight or bent (90 degree) forms.

 

[Goldspoon]

I posted then I rubbed it out... ignore me

 

[MartinT1967]

Hey guys

I am new to the forum and have a quick question relating to the thread on a toilet cistern inlet plastic thread.

Am I correct in assuming that if I can screw on a 15mm nut from a compression coupler then the thread size is 1/2" and all I would need to plumb in my new toilet is a 15mm to 1/2" flexible tap tail with an isolating valve inline to be able to service the cistern in the future.

Thanks in advance

Regards

Martin

 

[Terry lambert]

Yes

 

[MartinT1967]

Yes

Thanks terrydoh

Sort and exactly to the point!! Cheers