Manual operation, the direction is coaxial with the shaft core, easy to operate, accurate positioning, sliding column structure, good sealing, small size, light weight and easy to assemble and disassemble;the inner hole is processed with a special process, the friction resistance is small, and the service life is long;no need Refueling and lubrication;multi-position installation, easy to install and use;the hand valve is a manually controlled valve with various functions, such as reversing, opening and closing, etc. The so-called hand pull is relative to electronic control, pneumatic control or hydraulic control.