PART 2 TOILET FLOAT VALVE:

[RONCHAM]

My toilet cistern is mains fed but takes several minutes to refill so I decided to change the float valve. This should have been a 10 minute job but I hit problems which were sod's law and Catch 22 rolled into one.

The existing float valve is a Part 2 type so I bought a Part 2 replacement. The existing threaded inlet tail is about 23/8" (60mm) long but only about 11/2" (40mm) long on the replacement, so it would not reach the tap connector. The tap connector is difficult to modify as it is soldered onto a lead pipe emerging from the bathroom wall. It seems a long tail version is only available with Part 1 valves - which seems odd.

I bought a tail extender ie a brass 1/2" MI/1/2" FI. However, when this is pushed onto the tap connector, it barely leaves room to offer up the external backnut to the threaded inlet tail and insufficient exposed thread to wind on PTFE tape for the 1/2" FI connection.

It did occur to me that I could simply swap the valve internals by undoing the large nut inside the cistern but I was worried that another problem might arise to prevent me returning to the original arrangement.

One other complication is that the captive nut on the chromed/stainless steel tap connector does not run very freely/far enough along the short length of pipe up to the shoulder and it is extremely difficult to offer it up to the MI thread when a fibre washer is in place. The original tap connector joint was made with bosswhite and hemp (not a fibre washer) so I suspect it may be hardened bosswhite on the nut thread causing this problem - this would be awkward/impossible to remove. I eventually used several turns of PTFE "string" instead of a fibre washer.

Am I correct in thinking the 1/2" FI could also be connected with an olive to the inlet pipe, as in a normal compression fitting? - this would be easier than using PTFE tape. Though it does seem the olive could possibly misalign unless I paste it in position with bosswhite.

 

[PullerGas]

A picture is worth a thousand words!! What you English call an idiom.

 

[dilalio]

A picture is worth a thousand words!! What you English call an idiom.

And what do you Scots call it then?

 

[PullerGas]

And what do you Scots call it then?

Common sense.

 

[RONCHAM]

Here's a photo, although I don't see what it adds to my original description? - especially as many of the problems lie within or are not readily appreciated without explanation. The MI/FI extension piece is shown on top of the cistern but I'm sure all plumbers are familiar with this fitting. The new Part 2 float valve, also shown, is from a reputable manufacturer. My fundamental question is whether the MI/FI fitting can be connected to the tail of the float valve with an olive, as in a normal compression fitting? As mentioned, I would have to ensure the olive does not misalign as, once within the FI, it will not be visible.

Regards.

 

[Bosswhite]

It dosent need an olive The fitting on the water supply just screws onto the float valve tail ( just a fibre washer required)

 

[RONCHAM]

Hi - thanks for your response but I think you've misread the problem? The (tap connector) fitting on the water supply will not reach the float valve tail, hence the need for a MI/FI extension fitting. Also, it was very difficult to manipulate the nut (on the tap connector) onto the threaded end of the tail. Bosswhite and hemp had originally been used in place of a fibre washer for which I substituted PTFE tape (twisted into a string) on putting back the original float valve.

Regards.

 

[PullerGas]

Ah it's a wiped lead pipe joint fella!! Best bet is freeing up the tap connector nut. Or get a time-served Plumber in to wipe another joint. Don't expect any young pup or course cowboy to help you with that!!

 

[RONCHAM]

Yes, I appreciate that. And as such plumbers are a dying breed my best long-term solution would be to change all water pipes to copper from the stopcock onwards and replace lead waste fittings etc. with plastic. Then I could use any of the various "idiot-proof" products available now. But the ptfe "string" to the tap connector seems to have done the trick - and I don't suppose it will deteriorate? Else bosswhite and hemp which has stood up for years in the original installation.
But returning to my fundamental question - can the female iron side (of the MI/FI extender) be connected to the float valve tail using an olive?? I'm not sure if the thread on the nut of a compression fitting and the thread on a female iron fitting differ in some way (tapered/parallel?)?
And I'm still curious why they manufacture a Part 1 valve with a long tail but not a Part 2?? - especially as Part 2 valves are often recommended as best choice.

 

[PullerGas]

Ah, OK to connect the existing ferrile wiped tap connector to the 15mm/1/2" female adaptor, just use a fibre washer & plenty PTFE tape.

I'd also use some Boss White(generic name) on the PTFE, but the puritons on here may shoot me down in flames!!

 

[RONCHAM]

Thanks. But I'm talking about the connection of the 1/2" FI to the tail of the float valve (and the fact that there's insufficient tail thread exposed to wind on ptfe tape - hence the query about using an olive). I also said the existing tap connector (soldered onto lead pipe from wall) will not offer up to the MI if I use a fibre washer, hence I used ptfe "string" (the original joint here was made with bosswhite and hemp).

Regards.

 

[PullerGas]

Even with a short thread connecting the FI to the Part 2 tail it will seal to the brass jam nut if you make a PTFE tape 'face' washer.

Just using PTFE tape on the tap connector is fine, not a problem.

 

[RONCHAM]

Thanks again for that - I think I know what you mean by a PTFE face washer. But could I in fact use an olive?? Trying it "off-site" (where I can also ensure the olive is not misaligned) it tightens and feels like any compression fitting - but I wasn't sure how it would be under mains water pressure? I'm not quite sure what you mean by "brass jam nut"? - the tail will screw into the FI until it hits the shoulder within the fitting.
With the tap connector I initially used a few turns of PTFE (as the fibre washer that proved awkward was less than 1mm thick) - but there was a very tiny drip. I used a few more turns of PTFE "string" and that's done the trick.
I was very curious to know if I could use an olive on the tail end of the valve as it has a tapered inner end (like any compression fitting) to receive an olive.
But to be quite honest I think my best bet is to bite the bullet, undo the old valve backnut inside the cistern, and swap the innards with my new valve. And just hope there's no more unforeseen complications! By the way, I was very surprised to find the new valve had a hard plastic sealing washer behind its backnut - I expected a fibre or rubber washer??

 

[PullerGas]

Backnut = jamnut.

I wouldn't use an Olive as you detailed, they're designed to compress onto copper tube.

 

[RONCHAM]

Thanks again for all your help - makes sense. Someone suggested liquid PTFE which I'd have to progressively apply as I wound the FI onto the valve tail and gradually gained access to more of the thread, though I've no experience of using it. Any thoughts on that hard plastic washer? - seems unusual to me. And still curious about the lack of long-tail Part 2 valves - Part 2 seems to be the norm now so they must sell enough year on year. Any "surplus" thread could normally be contained within the cistern or water tank.

Regards.