What kind of float valve is this?

[Stratman]

Can anyone tell me what this type of valve is called? I need to do some investigation.

It won't shut off properly. I unscrewed part '2' where I found a rubber diaphragm with what I can best describe as a plastic 'posidrive' bit poking through its centre. There's also a tiny plastic pinhole grommet type thing through it..

I thought the operation was going to be of the standard Torbeck type, but the pivot '1' doesn't actually move anything. As the float rises, the float arm covers a small hole in the grey 'rod' to its right with an even smaller hole.

I cleaned everything and put it all back together. The first flush worked perfectly, shutting off as expected. The second and subsequent flushes didn't, the water level rose above the float and into the overflow. Another dismantling and reassembly did the same. First flush was good, the rest not so.

The cap '3' behaved differently on first flushes, the insert dropping slightly as it shut off. On subsequent flushes it stays in the 'up' position.

I couldn't see a way of removing the cap without breaking it, it looks to be a 'fit once and leave it' affair. Is it possible to take it off? If so how?

How are these valves supposed to work? As far as I can see there's a hole in the diaphragm by design, how can this work?

Is it worth trying to repair it, or what kind of valve should I fit in the limited space in the cistern?

It's fed from the high pressure rising main which I suspect could be the root of the problem, as another cistern (with a traditional syphon flush) doesn't shut off either because (I think) it fills faster than it flushes, so the syphon doesn't get broken and the incoming water literally goes straight down the pan.

 

[developer]

Generally it better to replace, as they are cheap, however, you may find a tear in the rubber in part 2, which may be replaceable.

Isolate it, take it apart, and go to a decent plumbers merchant for a new one.

 

[Stratman]

Thanks. The rubber diaphragm in part 2 looks in good condition, it's what's under 3 I need to look at but I can't see a way of removing the lid without risking breaking the tabs.

As you say, replacement is probably the better option. Are there valves specially for high pressure feeds, and if so are they commonly available?

 

[developer]

Really, I'd just remove it, take it along to the merchant and replace.

Don't forget to replace the fibre washer where the incoming water feed meets the float valve.

 

[Darrell]

Pull it out and replace it.

Don't try and get your head round it.

 

[Palfrem]

I'm with Developer - a cheap part, buy a new one.