Valves that are known as non-return valves, one way and clack valves are all the same type of valves. As defined by the check valves casting, these are all the different names of the same valve, popularly known as the check valve.
The ball check valve is one of the most popular valves in the market. These valves are usually small and inexpensive, which is why they are so commonly used.
Here is another type of check valve:
Another check flow device is known as a diaphragm valve. What makes this apart is that there is a flexible rubber diaphragm in place to make the valve closed.
As the pressure changes, the diaphragm is able to flex back and forth to allow the flow of liquid. This can vary significantly based on the overall diameter of the valve itself as well as liquids.
The stop-check valve is used for the prevention of backflow because it has override controls that would stop the flow even if there is a change in pressure or flow direction. You may want one of these valves if you want the ability to stop the flow without waiting for changes in pressure.
Swing mechanism commonly used in plumbing. This is because it uses what is known as the flapper valve where the pressure holding it closed. There is a disc or other moving parts that block the flow.
When there is no forward pressure at all, the gates remain closed. Otherwise, it will open, which is why it is used by firefighters and the will of the drainage system to avoid the flow of wastewater.