It is actually called a back water valve used mainly on waste systems to prevent raw sewerage from entering a structure during high tides or storms that may overload a drainage system.
Back water valve
To stop a toilet from running constantly, you can adjust the float level in the tank, check and replace the flapper valve, or clean the fill valve.
Check the angle stop. Check the supply line. Then check the fluid master valve.
It stops by passing of cold into hot and visa vera
Oil check valves are designed to stop the drain-back of oil. A replacement valve costs between $25 and $30 depending on where you buy it.
Check your EGR valve Check EGR valve
To stop a running toilet, you can adjust the float valve in the tank or check and replace the flapper if it is not sealing properly.
Check your EGR valve
check your egr valve or throttle positioning sensor
Check the egr valve.
Your presta valve may be leaking air due to a damaged or worn-out valve core, improper installation, or debris blocking the valve. Check for these issues and replace the valve core if necessary to stop the air leak.
A dual check valve is similar to a double check valve in that it is a mechanical backflow preventer consisting of two independently acting, spring-loaded check valve.