Apartment Hot Water Valve Leakage: Replacing Seals, Faucet, Washbasin, Water Supply Issues

Hello and welcome,

I have a small problem in the apartment and would like to ask for advice. I wanted to replace the seals in the faucet connected to the washbasin, and as you know, to get down to it, you should first cut off all water supply in the apartment ... and here there is a certain difficulty. While there is no problem with "turning off" the cold water, when you try to turn off the valve with hot water inlet, water starts to flow as if from the top of the valve ... directly to the entire installation. I don't know what this could be caused by? Some time ago the water meters in the apartment were replaced, maybe something was "set up" incorrectly.

I will be grateful for any tip or advice.

Thank you!

The main point is that when you turn off the valve with hot water, water flows from the top of the valve, as if the gasket was incorrectly fitted.

This is strange because when the valve is turned on, the water in the tap normally flies, and there nothing drips from the pipes from the valve, and when this valve turns off, water from these pipes immediately flows from the valve.

Hello
You probably have a valve similar to the one in the attached picture:

or:

If you look closely, you will notice an additional seal on the top of the valve shaft, tightened by a screw (2 photo) or a special nut (1 photo). Sometimes the seal has to be tightened slightly by tightening the bolt / nut.

The valve looks something like this:

As above, besides what kind of ram put this valve on? to change it, you need to cut out the fittings .
When replacing the valve, have them put on the unions.

Thanks a lot for the answers. The photo above was an example to illustrate the type of valve. Today I do not have such a possibility, but tomorrow I will try to take a photo of a specific case. The fact is that the water seems to run from above from the part to which the red butterfly is attached.