Sealing oil has a lubricating and cooling effect, and also to prevent leakage of conveying medium and negative pressure air or flushing water into the role of the stuffing box.
Sealing oil pressure should be higher than the sealed medium pressure 0.05 ~ 0.2mpa, sealing oil should be clean, no particles, not easy to evaporate gasification, does not affect product quality of non-corrosive liquid. Oil sealing system usually includes pumps, tanks and pressure balance, filtration, cooling and other auxiliary equipment.
Application characteristics
There are two kinds of vacuum device sealing, one is the sealing of a container filled with liquid medium and the external vacuum space divided. In this case, the main role of the seal is to prevent the liquid medium leakage into the vacuum space. The other case is the seal to the vacuum cavity and the outer cavity divided, its role is to maintain the required degree of vacuum.
This situation is more complicated because even a slight leakage of the surrounding gaseous medium into the vacuum cavity will reduce its vacuum level. If corrosive gases leak in, the vacuum equipment can be damaged. In many cases, the vacuum level and the cleanliness of the vacuum space have a decisive influence on the quality of the various processes carried out under vacuum conditions.