Transmission failure often manifests as a blocked valve stem, inflexible operation, or inoperable valve. The reasons are: the valve is rusted after being closed for a long time; improper installation operation damages the valve stem thread or the valve stem nut; the gate is stuck in the valve body by foreign objects; the gate is often in a half-open and half-closed state, subject to water or other impact Causes the valve stem screw and valve stem wire to be misaligned, loosened, and bitten; the packing is pressed too tightly to hold the valve stem; the valve stem is ejected or blocked by the closing piece. Lubricate the drive parts during maintenance. With the help of a wrench and gentle tapping, it can eliminate jamming and ejection; stop water for repair or replace the valve.