In the spout opening of many taps there is a filter thing. It is not actually a filter at all but this is what it gets called a lot of the time.
So, what is it Supposed to be called?
and what is it for?
Call it an aerator or diffuser and you will be on the right track. I have heard it referred to as a filter and gauze sieve but these are not correct.
This clever piece of technology changes the way water exits a tap spout. The Aerator is either wire mesh or plastic grate and is screwed to the tap spout end, often with a chrome collar (the pics above show the aerators inside chrome collars). The water is agitated in the aerator and mixed with air that enters through tily channels in the side so when it comes out of the spout it feels luxuriously soft and bubbly.
Aerated water is gentle and pampers your hands.
Aerators also act to direct the water flow straight out of the tap spout and minimise splashing.
The aerator also restricts the water flow along with adding air to the water so it is also a water saving device.
Aerators are common on kitchen taps and basin taps where the spout shape allows. Square and waterfall spouts often dont have. You can easily see the aerator in tap pics, it either protrudes from the spout or you can see the screw collar line on the spout end.
They are not so common on bath taps as the restriction will slow down filling the bath tub and you dont usually wash your face or hands direct from the bath tap spout.
Aerators often get clogged by debris, especially in new installations or after pipework repairs or maintenance. This gives the impression that the pipes are blocked and often leads to major investigation and costly plumbers bills when all that is needed is to unscrew the aerator and rinse it clean.
Taps that usually have aerators:
Taps that often dont have aerators: