Fusible fire-proof emergency cut-off valve

A fusible fire-proof emergency cut-off valve, comprising a swing check valve (10) and a control mechanism (19), wherein the swing check valve (10) comprises a valve body (11), a rotating shaft (20), a valve cover (13) and a valve plate (12), two sides of the valve body (11) are communicated with an outlet (1) and an inlet (2), respectively, the inside of the valve body (11) is rotationally connected with the rotating shaft (20), and the valve plate (12) is fixed to one side of the rotating shaft (20) and is positioned at one end of the outlet (1);

• the control mechanism (19) comprises a shifting fork box body (15), one side of the shifting fork box body (15) is connected with a second cylinder (8), and the other side of the shifting fork box body (15) is connected with a first cylinder (7);
• the other side of the rotating shaft (20) is inserted into the shifting fork box body (15) and fixedly connected with a shifting fork (16), one side of the shifting fork (16) is provided with a clamping groove (5), the inside of the second cylinder (8) is provided with a piston rod (17) penetrating through the shifting fork box body (15) and the first cylinder (7), a limit piston (9) is fixed to the left side of the piston rod (17) and is positioned inside the second cylinder (8), the right side of the limit piston (9) is provided with a spring (14) sleeved outside the piston rod (17), a shaft pin (3) inserted into the clamping groove (5) is fixed to the outside of the piston rod (17), and the right side of the piston rod (17) is connected with a fusible pin (18) penetrating through the first cylinder (7).