Reasons for valve fluid leakage:
1. Reasons for gas leakage: The number of molecules that hit the leak seam from the outside is less than the number of molecules on the inside.
2. Causes of liquid leakage: There is a gap larger than the molecular diameter on the sealing surface, and the liquid molecules squeeze out of the gap under the intermolecular repulsion to cause leakage.
3. The different requirements of macro seal and micro seal for sealing pair: the former is allowed to be a "labyrinth" seal, while the latter is a real "zero leakage". such as micro leak detection.
4. "Smooth sealing" and "damage sealing": the former requires high precision and prevents scratches, the latter allows the sealing effect to be achieved through predictable damage, and the latter expands the range of design options, reduces processing costs, and reduces product costs.
5. Contact sealing mechanism.
Valve manufacturers
Valve manufacturer maintenance method:
1. The material and type of packing should be selected according to the working conditions;
2. The packing should be installed correctly according to the relevant regulations, the packing should be placed and pressed one by one, and the joint should be at 30°C or 45°C;
3. The fillers that have been used for too long, aged and damaged should be replaced in time;
4. After the valve stem is bent and worn, it should be straightened and repaired, and if the damage is serious, it should be replaced in time;
5. The packing should be installed according to the specified number of turns, the gland 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 components should be repaired or replaced in time;
7. The operating procedures should be followed, except for the impact handwheel, which should be operated 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.