Plumbing

A Ball Valve is useful for shutting off the flow of water as a shut-off valve, hydraulics, for water and gas.

The image at the top of this page shows a Male/Female 15mm Ball Valve. This could be put in place where a short extension was and  the female end to the pipe and the male end to a Flexi Pipe and then to a tap or whatever, so you can turn off the water should you need to work on the tap without turning off the main water supply to your home or building.

They can also be used to restrict water flow (Control Valve) but they are not very accurate for that purpose.

They are known for having a long service life and they provide a reliable sealing, even when the valve is not in use for a long time.

For a more in-depth read about these valves go here:
https://tameson.com/ball-valve-introduction.html