Dual flush push button

[Fallout]

How does the push button react different to cause the dual flush features on a flush valve. Not a Syphon. Thanks

 

[HERTS P&D]

They push the flush valve down half way which is a half flush or all the way down for a full flush.

Andy

 

[Fallout]

Thanks and what holds the flush valve open after release?

 

[HERTS P&D]

The design

Andy

 

[Fred Blogs]

The flush valve is held open by the pressure of the water flowing through and the valve drops back down as the water pressure decreases.

 

[Sid1968]

Yeah, alright, it’s all about the water pressure. When you push the button, it opens the valve and water pressure keeps it up until the flow slows down, and then gravity closes it. Simple but clever design.

 

[Fallout]

Thanks and with the short flush it only opens the valve say half way?