Abstract: It is disclosed a shut-off valve which acts automatically and has a fully mechanical performance with respect to the loosing of the tower-shape part balance under the effect of the special acceleration which is arisen from the quakes waves or serious vibrations, while such vibrations are mainly resulted from collision or effusion. A static tower has been applied for the main core of this part of the valve which loses balance state under the effect of collision and bounces to the neighboring part, which results in release of the catch and blockage of the gas passing channel.