Causes and maintenance methods of the main parts of the leakage of the valve
The leakage of the valve, the proportion of the packing is the largest. The main reasons for the leakage: 1. The packing is not selected correctly, it is not resistant to the corrosion of the medium, and it is not resistant to the use of high pressure or vacuum, high temperature or low temperature of the valve; 2. The packing is installed incorrectly, and there are problems with the use of small instead of large, poor spiral coiled joints, tightening and loosening 3. The packing has aged and lost its elasticity after it has exceeded its service life; 4. The valve stem has low precision, with defects such as bending, corrosion and wear; , bolts, and other parts are damaged, so that the gland cannot be pressed; 7. Improper operation, excessive force, etc.; damage. Maintenance methods for packing leakage: 1. The material and type of the packing should be selected according to the working conditions; 2. The packing should be installed correctly according to the relevant regulations. The packing that has been used for too long, aged and damaged should be replaced in time; 4. The valve stem should be straightened and repaired after being bent and worn, and the damaged one should be replaced in time; 5. The packing should be installed according to the specified number of turns, and the gland should be installed. It should be tightened symmetrically and evenly, and the pressure sleeve should have a pre-tightening clearance of more than 5mm; 6. Damaged glands, bolts and other parts should be repaired or replaced in time; 7. Operation procedures should be followed, except for the impact handwheel, Operate at a constant speed and normal force; 8. Tighten the gland bolts evenly and symmetrically. If the gap between the gland and the valve stem is too small, the gap should be appropriately increased; if the gap between the gland and the valve stem is too large, it should be replaced.