Typical Installation of Shut-off Valves
Residential toilets or faucets are typically installed with shut-off valves, also known as “angle stops”. These valves can be found behind the toilet. Each sink in your house typically has two shutoff valves to allow for the hot or cold water to be shut off separately. Other plumbing fixtures such as washing machines sometimes have shut-off valves as well.
Most shut-off valves are screwed on, although some are soldered directly to the pipe. All shut-off valves have compression fittings for connection to the fixture. It is not unusual for a shut-off valve to leak due to corrosion.
A defective shut-off valve is highly uncommon but sometimes does occur.