Technical requirements for valve stem packing and turbine transmission

Valve shaft packing:

1. Due to the infrequent opening and closing of valves in the pipeline network, it is required that the packing should remain inactive for several years, and the packing should not age to maintain a long-term sealing effect.

2. The valve shaft packing should also have good sealing performance when subjected to frequent opening and closing.

3. In view of the above requirements, the valve shaft packing should be kept unchanged for life or more than ten years.

4. If the packing needs to be replaced, the valve design should consider measures to replace it under water pressure conditions.

Transmission gearbox:

1. The material of the box and the requirements for internal and external anti-corrosion are consistent with the principles of the valve body.

2. The box should have sealing measures and be able to withstand immersion in a 3-meter water column after assembly.

3. The adjustment nut of the opening and closing limit device on the box should be inside the box.

4. The transmission structure is designed reasonably, which can only drive the valve shaft to rotate during opening and closing, without causing it to move up and down. The transmission components are moderately engaged, and there is no separation slip during load opening and closing.

5. The gearbox and valve shaft seal should not be connected as a leak free whole, otherwise reliable anti leakage measures should be taken.

6. There are no impurities inside the box, and the gear meshing area should be protected with lubricating grease.