Underloading type butterfly valve

The utility model relates to an underloading type butterfly valve, including the valve body, the valve plate sets up in the inside of valve body, the both ends of valve body still the symmetry set up preceding support frame, back support frame, front valve axon head, back valve body spindle nose, the one end of preceding spindle nose stretches into valve body in -connection circle sleeve 's one end, and the one end of back spindle nose stretches into valve body in -connection circle sleeve 's the other end, connect air cooling head -clamp cover respectively on front valve axon head and back valve body spindle nose, in the periphery of preceding spindle nose and back spindle nose still top -down cooperation gland, dismantle the formula packing box, gland's one end stretches into dismantlement formula packing box, the one end of dismantling the formula packing box stretches into front valve axon head or back valve body spindle nose. The utility model discloses a move the bearing unit to the valve body outside,