Tamper-evident device and valve using same

A tamper-evident device for a valve having a passage outlet on a body thereof, comprising:

• an anti-theft buckle including anti-theft buckle body, pulling portion, tearable portion and elastic hook provided with a position limiting surface, wherein the pulling portion is connected to the anti-theft buckle body via the tearable portion;
• an anti-theft cover provided with position limiting contour and hook receiving portion;
• and
• a position limiting slot provided on the outer periphery of the passage outlet,
• wherein when the tamper-evident device is installed, the anti-theft cover is connected to the passage outlet, the elastic hook being snapped into the hook receiving portion along the limiting contour and engaged with the position limiting slot, such that the relative positions of the anti-theft cover and the body of the valve are limited, and
• wherein one end of the tearable portion extends to a position close to a snapping surface of the elastic hook;
• the tearable portion can be torn from the anti-theft buckle body through pulling the pulling portion, which causes the elastic hook to be deformed and pulled out of the hook receiving portion and the position limiting slot, so that the anti-theft buckle is detached from the anti-theft cover, and then the anti-theft cover can be detached from the body of the valve, wherein the tearable portion cannot be recovered after being torn.