Is the tank stop valve a non-return valve or a check valve?
The valve has a knob, and the controller can control the forward flow. Because of its special structure, the fluid can not flow backwards even if there is no artificial valve.
Check valve is a one-way valve, automatically prevent reverse flow of fluid, no knob, can not be artificial blocking forward flow.
The check valve is not the same as the cut-off valve. The difference between them is mainly that the structure is very different.
