On Sep 28, 6:20�pm, Alfred K. wrote:
On Mon, 28 Sep 2009 15:44:00 -0500, Alfred K. wrote:

Consider an extreme situation: a fully opened faucet and a completely
closed pop-up bathroom sink drain. Should a properly installed overflow
opening actually prevent the sink overflowing? Or it is supposed to
just help the main [open] drain by lowering the about to overflow water
level down faster?

Is this a vessel sink?

No, it's a "regular" one but the spring-loaded pop-up drain that was
included with the sink has been replaced with the handle-operated one
that came with the faucet. It could be that the internal cut (within
the pop-up body) that is made to accommodate the overflow stream is �
partially blocked...

What is the practice of marrying the sinks with overflow openings with
"non-native" pop-up assemblies to avoid such obstructions?

most anti flood holes dont accept the full flow from a faucet with a
fully blocked drain./

i looked into this many years ago when replacing my bathroom sink