As far as I know, its usually a loose washer in the piping somwhere or a mishapen one. An old plumber told me if you hammer the washer on flat surface, that can correct it. Basically as you run the water it resonates creating the noise. The washer is probably in the faucet btw. Like I said I'm no expert just saying from experience.
There are a few causes for a hot water line in the kitchen to squeal when it is turned on. There could be a leak in the line.
Clogged aerator.
The water pump.
It can be several things, either by themselves, or in combination. 1) the belt has dried up and isn't as grippy any more. This causes it to slip and squeal. There are sprays available to restore grip on belts which might help. 2) the belt has stretched a little, which causes it to slip and squeal. Retension, usually by adjusting the alternator position and it should be OK. 3) one of the auxilliaries(alternator, power steering pump, water pump) is about to seize. If it's harder to rotate the belt will slip and squeal.
To drain the water that is in the pipe or spout..
A water faucet is the mechanical device fitted to the water supply pipes over bathroom and kitchen sinks. When turned on they supply water.
The belt will not generally squeal, but the water pump often makes a "Scrapy-scrapy-scrapy" sound.
choir members in your pipes
The force of the water hitting the pipe constantly is enough. Air in the system
they squeal because they are eathier hungry and need more food or they are thirsty and need more water.
Yes, remove your old shower valve and fit a new Moen anti-scald valve. This will not change when other items are turned on.
Valves under the sink NO WORK HUH?
Lose washer / excessive velocity (FPS)