(1) improper selection of fillers.For example, the selected filler is not resistant to medium corrosion, high pressure or vacuum, high temperature or low temperature, etc.
(2) packing gland is not compressed.Only when the packing is subjected to a certain pressure, can the packing produce a certain radial deformation, filling the gap between the pump shaft (stem) and the inner wall of the packing cylinder, thus playing a sealing role.When the pressure is very small, the packing radial deformation is very limited, sealing effect is relatively poor.
(3) the packing is too thin.If the packing is too thin, when it is squeezed by the packing gland, the radial deformation produced by the packing gland itself is limited and does not provide a good seal.
(4) the filling is cut too short to close the two sections.
(5) the number of packing mounting laps is too small to meet the use requirements.
(6) improper packing installation.It is mainly due to the packing incision Angle is too large or too small, the packing section contact way is not correct, and the packing round incision is not staggered, and so on.
(7) improper or ineffective filler lubricant selection.Lubricant for impregnated packing ropes must have good retention, lubrication and film forming properties.When the lubricant is improperly selected or fails, the packing rope is not impregnated with lubricant, the gaps between the fibers are not sealed, and the pump shaft (stem) is not adequately lubricated.If the filler is aged and dry, the filler lubricant has failed.