Details
Stem packing seals are a form of sealing used at the stem of a valve.
It mainly consists of a filler and a stuffing box. The packing is generally a soft and flexible material, such as asbestos, graphite, PTFE, etc., woven or pressed, which is filled in the space between the stem and the stuffing box. A stuffing box is a fixed part that is used to hold the stuffing.
It works by tightening the packing gland bolt when the valve is closed or opened, so that the packing is compressed, so as to fill the gap between the valve stem and the stuffing box, preventing the medium from leaking outward along the valve stem. This sealing method can adapt to a certain degree of stem movement, and can adjust the compression degree of packing according to the actual leakage situation to maintain a good sealing effect. However, with the time and frequency of use, the packing may wear out and need to be replaced in a timely manner to ensure sealing performance.
Stem seals are primarily used to prevent fluid leakage along the stem.
It is sealed by the close contact between the sealing ring and the valve stem. The sealing ring is usually made of an elastomeric material such as rubber and is installed in the appropriate position on the valve stem. When the valve is closed, fluid pressure acts on the seal, allowing the seal to fit the stem better and stop the fluid from seeping. This sealing method can effectively protect the internal structure of the valve, and can also reduce the loss of medium, and is widely used in various valves such as gate valves, globe valves and other equipment.
