Plunger packing seals is also called sealing packing, which is usually braided by softer wires, and is filled in the sealing cavity by strips with a square cross-sectional area, so as to achieve sealing. Next, let us work with XinRuiTuo to learn about the technical requirements of plunger packing seals and the selection of suitable plunger packing seals.
skills requirement:
- When cutting the plunger packing seals, it is best to cut the packing around a round steel rod with the same diameter as the valve stem to ensure that the size is correct and the cuts are parallel. The incision should be clean and free of loose asbestos threads. The incision is preferably at a 45° angle.
- Each packing ring shall be individually pressed into the packing box. When pressing the valve packing, a small amount of scaly dry graphite powder or lubricating oil should be placed between each circle.
- In order to facilitate installation, when pressing the aluminum foil-wrapped asbestos packing, a thin layer of scaly graphite powder mixed with engine oil should be applied to the inner edge of the packing.
- The width of the selected packing should be consistent with the size of the packing box, or 1 to 2 mm larger.
- When pressing oil-impregnated asbestos packing, it is best to press dry asbestos packing in the first and last laps to avoid oil seepage.
- When pressing the packing, the interfaces of the packing ring must be staggered, generally the interfaces are staggered by 120° or 180°; the packing should not be pressed too tightly and should be adjusted according to the working pressure.
- The depth of the gland pressed into the packing box is generally the height of a circle of packing, but not less than 5, and there should be room for further tightening.
- When installing the gland, the gap between the packing gland and the valve stem should be kept consistent to prevent pressure deviation, causing uneven force on the packing and rapid wear. Generally, the gap should be kept not greater than 0.1 to 0.15.
- The main points to ensure the quality of packing installation are: choose correctly; check carefully (check valve stem, packing box, packing, etc.); The size is accurate; the pressure is good (the first circle is pressed well, so that the deformation of the packing after pressing is the same, and the thickness is consistent).
How do I choose the right plunger packing seals? There are two things that must be considered when choosing packing:
- The requirements of the working conditions should match the performance of the packing. The packing that best meets the requirements can be selected according to relevant technical data.
- The packing size must be correctly selected according to the sealing requirements. In order to determine the cross section, please use the following formula to calculate: cross section = (stuffing box diameter - valve stem diameter); damaged devices may require packing with a slightly larger cross section to compensate for the damage.
The above are the technical requirements for plunger packing seals and the selection of suitable packing that Xinruituo sorted out and shared. For more information, welcome to continue to pay attention.
