i wanted to know what is the actual difference between check valve (non return valve) and globe valve?
A check valve stops water from going back through the water line . A globe valve is a type of valve that uses a ball shaped device with a series of holes which regulate water flow , normally found in household water supplies. The other type of valve is a gate valve, which is used where a larger flow is regulated, like in most commercial applications.
Check valve/non-return valves are unidirectional, meaning flow can only go through them one direction. Check/Non-return valves usually don't include any kind of manual actuation. Globe valves have a sphere with a hole cut through it, as the globe is rotated within the housing, the hole aligns with the valve inlet and outlet, or is sealed from the inlet/outlet by the valve casing. Thus, the handle/knob is used to rotate the ball, thereby opening or closing the valve. Because the hole is cut cleanly through the ball, flow through a globe valve is bi-directional.
Check valves are designed to prevent back flow. A globe valve is used when the ability to throttle and control the flow is desired. The globe valve can be positioned at anywhere from 1% to 100% flow. This allows for very precise control over how much liquid will be allowed to flow through the valve. There is another type of valve called a gate valve. The gate valve can not be positioned with such precision as the globe valve and it is used when flow rate is not as important.
A non-return valve is a globe valve with the disk attached so it can slide up and down. Back pressure will shut the valve even if the handwheel is in the open position. There will be a direction of flow arrow cast or stamped into the valve body. A regular globe valve has the disk threaded or pinned to the stem so it can't fall down. The previous answer was referring to a flapper type check valve and you can easily see by the valve body that they are not the same.
