cold water tank float valve

[dsgboy]

ive had problems with overflow running - i decided would try to resolve and bought a new type 2 valve for the cold water tank. however, the tank does not seem to have the standard fitting. Is the valve in the pictures easily replaceable? I don't understand the fitting or how you would remove it. what are the options for this? Ithink it is fitted c 1970.

 

[chris watkins]

You will have to unwind the old Portsmouth ball valve from the female iron fitting.

Loosen the back nut on the outside of the tank as far as it will go then start to turn the ball valve until it comes out of the fitting. You might need to check & wind down the back nut if it move up to the tank.

 

[chris watkins]

To fit the new one you will need just the union part to start with, leaving one of the back nuts on the thread right up close to the union end.
Push it through the hole in the tank & screw on the other back nut so it is on the out side & run it up the treads at least 20mm now apply PTFE & paste if you have some which is suitable for wholesome water to the very end of the threads before screwing it into the female fitting on the incoming pipe work.
Keep the back nuts loose at all times until the threaded tail is tight in the fitting only then tighten the back nuts to hold against the walls of tank.

Finally fit the float valve end to the union & turn water back on.

Your problem will be getting a spanner to grip onto the soft brass threads to be able to tighten it right home into the fitting which is where the Plumbers knowhow comes into its own.
Best of luck.

Of course a Plumber might just elect to alter the incoming pipe work & fit a tap con.

 

[Best]

Or you could attempt a repair of the existing valve, - new high pressure washer (that's the smallest type), sometimes new high pressure "nozzle" and a new brass split pin, if it is rotten.
You can buy those in a kit in big DIY stores.

 

[dsgboy]

thanks for those very helpful descriptions.

I've replaced the ball float as this was full of water - old one probably worth a bit in scrap!
I managed to get the old washer out - it was totally disintegrating, but found it was not a standard size. it sits in a two piece metal cylinder with a collar, which i unscrewed to access the washer. I cut a mm or so off two new ones to fit into the space of the old one - it seemed the old one was thicker. After i screwed the washer piston back together again, the new washer curves outwards slightly as it is gripped by the metal collar - I hope that doesn't mean i overtightened this.
I guess to access the nozzle will require me to remove the valve and access it from the back of the valve? I'm torn between attempting this as a learning project, and just saving my time and getting someone in to rework the connections at the back.

Oh, and the new standard sized type 2 valve unfortunately has a thread connector of a smaller diameter than the existing one. I realise this means I got the wrong thing, but was there an older standard for this?

 

[plumben]

Looks like it could be a Asbestos Cwsc to me, Maybe some of the more time served guys on here will have a better idea

 

[chris watkins]

GRP not asb cistern (tank)

I think the "nozzle" orifice is fixed in those old ones but best off replacing the whole thing.

It shouldn't be smaller dia, all domestics are 1/2" BSP thread, new will fit old.

End of the day if you are not sure get a plumber in, a learning project has a nasty habit of turning into I have got not water cos it all went wrong.

Once again good luck

 

[dsgboy]

Looks like it could be a Asbestos Cwsc to me, Maybe some of the more time served guys on here will have a better idea

Oh I see exactly what you mean - it does look suspiciously white. On the rim it says "OSMAGLASS" which I sort of assumed was a type of brand fibreglass, but I will need to confirm this before risking disturbing it.

 

[Best]

I had forgot that valve will have a fixed nozzle part. If it is rotted, as brass can become, then best new valve.
The washer to fit into the piston does need to be sometimes filed down to correct diameter and for some reason a lot of new washers are also far too thick. I think the washers in the single valve repair packets are about right thickness and just need diameter matched by using a file.

 

[dsgboy]

thanks to all for the incredible and generous advice.
the new float and washer seem to have bedded in and are working! fingers crossed