In case you don't know, curb stops are water service shutoff valves, usually located in the piping near the curb (between the water main and the building). This valve is used to start or stop the flow of liquid from the main water line. ... Curb stop valves are required for most plumbing and irrigation applications.
How does a curb stop valve work?
Most of these valves are enclosed in curb stop boxes. The cast-iron housing protects a pipe that extends to ground level with a removable cover. The curb stop water valve is accessed with a special wrench or key, which slides down the pipe and turns the valve on or off.