Leakage of filler and connection between valve body and bonnet (1) Leakage of packing leakage and reasons: Packing seal principle: The axial force applied to packing, plastic deformation of packing, the valve due to multiple packing installed, the parts alternately contact each other to form "Labyrinth effect", play a role in preventing leakage of pressure medium outside. In addition to the filler leakage under different pressures and media penetration, the filler of the contact pressure is not enough, there are the aging of the filler itself, the stem of the injury and other reasons. The packing corrodes the valve stem so that when the pressure leaks out of the media along the contact gap between the packing and the valve stem until it leaks from the packing, otherwise the valve is bent excessively with excessive force. Filler improper selection, impatience media corrosion, impatience high pressure or vacuum, high temperature and low temperature. Filler over the service life, aging, loss of elasticity Packing insufficient number of methods of treatment: should be selected according to working conditions, packing materials and materials; pre-packing, the correct installation and determine the number of packing; stem bending, surface corrosion mechanical repair or replacement; Filler failure must be replaced.