Ammonia valve with cut-off and non-return functions

The utility model belongs to the technical field of valves, and particularly relates to an ammonia valve with cut-off and non-return functions, which comprises a valve body, an upper end cover is mounted at the upper end of the valve body, a valve rod is arranged in the upper end cover, the valve rod is in threaded connection with the upper end cover, a hand wheel is mounted at the upper end of the valve rod, and a sealing element capable of moving axially is mounted at the lower end of the valve rod. According to the stop valve, through the design of the movable sealing piece, the valve rod moves downwards, the stop function is achieved, after the valve rod moves upwards, when the pressure intensity in the inlet channel is larger than the pressure intensity of the outlet channel, the valve rod is closed, and the valve rod is opened. When the pressure in the outlet channel is larger than that in the inlet channel, the fluid can push the sealing piece to enable the sealing piece to be attached to the annular s