John Weston wrote:
Chris Bacon says...
The flap valve is [ in a lavatory cistern ]
a crap idea that should be consigned to the dustbin.

Yes agreed - what are they called as I need yet another
replacement rubber seal for my "drop stop", no syphon flush

Sorry, I don't know. Nonseals? I was apalled to go somewhere a while
ago abroad, where these things were in general use.The buggers leak.
Our pinnacle of flush technology was unheard of. In this place, mains
pressure was only available about 15 hours a day (and only where it
was specially installed - some people did not have it). They had to
"save water" in jugs, etc - not ideal in a place like that - if loads
hadn't escaped from these flaming poxy things, I bet that the problem
would have been alleviated. They really should be scrapped. We complain
about water company pipe leaks, & install these things! Money I s'pose.