Wetshaving requires water, and water means pipes and valves. And all that means that somewhere there has to be a water shut off valve, so I can shut off the water whenever a packing or O-ring needs replacing in a tap. Thus the main water shut off valve can be considered an “attaching and connecting part” of my shave

In my case, the shut off valve have – as I discovered a little while ago – corroded to the point of not shutting the water off. And since a water shut of valve that isn’t shutting the water off kind of negates the whole point (not to mention means that I can’t change the O-ring in the tap that drips), it was time to call in the professionals; i.e.: the plumber.
So out with the old:

And in with the new:

Whole thing done in less than an hour, including small talk and paperwork. And yes, it does shut off completely, allowing me to replace O-rings in peace…