What kind of flush valve is this?

[Bob White]

Did a 22 yr old log house today, and the upstairs bathroom toilet had this flush valve in the tank:

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I don't have any pic's from another angle. The thing was between 1' and 2' tall, and just squatted in the bottom of the tank.

I've never seen one before. It worked great.

What do you call this thing, and how does it work?

[Brad Manor]

I installed those in my own house about a year ago, they're great. The weight of the water on the little metal strip closes the valve, water level is adjusted with the little knob. They are a lot quiter as they fill too.

-Brad

[Bob White]

Asked and answered.

Thanks

[Nolan Kienitz]

Short of a flush valve ... I think have been called a "hush" valve or ballcock. Was just glancing over some plumbing posts elsewhere and some folks like 'em and some folks don't like 'em.

They indicated that adjustment for maximum flow/fill, etc. was a bit finicky.

Pressure sensitive to water weight from what I can tell.

Minimal 'moving parts' ... less to break.

[Jim Katen]

Originally posted by Brad Manor

I installed those in my own house about a year ago, they're great. The weight of the water on the little metal strip closes the valve, water level is adjusted with the little knob. They are a lot quiter as they fill too.

-Brad

Since there's no air break, how is it that they aren't considered a cross connection?

- Jim Katen, Oregon

[Brad Manor]

Good question, and one I had posed to a plumber friend of mine not long ago. He was a bit miffed. A little digging around on line led me to the patent summary of the "hush valve". It states :

For sanitary considerations, ballcock assemblies must be provided with a means for preventing the reverse flow of water from the toilet water reservoir into the water supply line. Typically, a vacuum break is provided within the ballcock valve to prevent water from flowing from the hush tube into the water supply line when a subatmospheric pressure exists in the supply line. Although such vacuum break systems operate satisfactorily, it is desirable to provide additional safeguards to prevent water backflow.

Looks like it's time to reconsider this "quiet wonder".

-Brad

[Les]

They are not allowed in most jurisdictions, cross connection, not anti-siphon. Some are anti-siphon if marked as such, but few and far between around here.

Been around for twenty plus years, not good for hard water use.

[carle3]

Yes, this style of ballcock valve is considered a cross connection.