Analysis on the causes and solutions of internal leakage of electric control valve

1) The fault caused by the packing is caused by the problem caused by the packing, which is specifically manifested in the increase of external leakage, the increase of friction force or the jumping of the valve stem. The main reasons are as follows: First, it may be that the filler material is not suitable. If it is not suitable for PTFE filler under high temperature application environment, the seasoning should be replaced; Second, the packing is not properly installed. For example, installing graphite packing in a spiral way will cause uneven packing pressure; Third, the packing design cannot afford to be too large, for example, the height of the installation position is not clear, so it is better to install according to the instructions; Fourth, there are sundries in the packing, which cause the valve stem to scratch. What we need to do is to remove the sundries.