American Standard inflow valve - how does it work?

[Kevin2023]

Someone here should understand this. I've just changed out an American Standard inflow valve on a toilet cistern, (it was getting slow at shutting off, and causing water to go down the overflow). All fine now, but the minor irritation is that I can't see how it was supposed to work!

There is only a small hole in the top of the assembly, that the float lever blocks when it's raised.

How is blocking that hole supposed to shut the water supply off?

(I've had a search around, but can only find references to the "old fashioned" type that I can understand!)

Thanks for any insight you can provide.

 

[CT18]

Maybe a picture of what you have

 

[Kevin2023]

No, sorry, I don't have it any more. not that it looks any different to this:

 

[Geofd]

Under that blue cap is a rubber disc with a small needle that goes thru it that's what fails in this type of fill valve

 

[Kevin2023]

Hi Geofd, thanks for responding, yes, you're right, the top comes off with 1/4 turn a/clockwise and reveals a rubber contoured washer with a hole in the middle that fits over a fixed plastic "pin' in the top section.

I just can't work out the mechanics of how the combination of this, and blocking a hole in the top casing to the exterior would ever shut the water supply off!

 

[breplum]

It is fluid dynamics. Flow of water through the well engineered pathways. It is not just a pin and hole.
LMGTFY on Youtube:

 

[Kevin2023]

Hi, Many thanks for trying to help, but this is not a Fluidmaster, it's an American Standard and there is no direct link to the float rocker arm. There is just a tiny hole, maybe 1mm, in the top plastic case which is blocked by a rubber bung when the float rises.

 

[SHEPLMBR]

Hi, Many thanks for trying to help, but this is not a Fluidmaster, it's an American Standard and there is no direct link to the float rocker arm. There is just a tiny hole, maybe 1mm, in the top plastic case which is blocked by a rubber bung when the float rises.

Fluidmaster makes them for Am Std

 

[Geofd]

Fluidmaster makes them for Am Std

Yes, they are also in some Kohler I beleive

 

[Kevin2023]

This is one that's still working fine, so I don't want to dismantle it. There's nothing attached to the short end of the rocker, it just closes a vent hole.

 

[SHEPLMBR]

I don't see the overflow tube

 

[Kevin2023]

I don't see the overflow tube

Do you mean the refill tube? There isn't one. It's blocked off.

The overflow tube is the cream one at the side or the bottom right.

I'm thinking this is more of a niche question than I first thought. Thanks to breplum, it's obviously to do with fluid dynamics, and it must work along similar lines to the Fluidmaster, with varying pressures operating the shut off somehow, but in the absence of any more detail, I think I'll have to admit defeat.

Thanks anyway.

 

[SHEPLMBR]

Do you mean the refill tube? There isn't one. It's blocked off.

The overflow tube is the cream one at the side or the bottom right.

I'm thinking this is more of a niche question than I first thought. Thanks to breplum, it's obviously to do with fluid dynamics, and it must work along similar lines to the Fluidmaster, with varying pressures operating the shut off somehow, but in the absence of any more detail, I think I'll have to admit defeat.

Thanks anyway.

Yes refill tube