Manual air valve for ventilation engineering

The manual air valve structurally comprises an adjusting valve, a support, a valve plate, a valve body and a valve rod, the adjusting valve is installed at the top of the support and connected with the valve rod at the bottom, the valve rod is arranged in the middle of the valve plate, the valve plate is movably connected with the valve body through the valve rod, and the support is fixed to the top of the valve body in a welded mode. The adjusting valve comprises an adjusting seat, a supporting top plate, an adjusting handle, a locking handle and a buckling part, the supporting top plate is arranged at the top of the adjusting seat, the adjusting seat is connected with the adjusting handle through the supporting top plate, and the adjusting handle is connected with the locking handle through a movable rod; the device has the beneficial effects that the mounting angle of the top adjusting handle and the locking handle can be adjusted through cooperation of the upper sliding sleeve and the bottom sliding sleev