Storage and use of grease
One. Grease storage
There are many varieties of grease and different properties. The grease is more susceptible to deterioration than oil, and it is difficult to handle the impurities after mixing impurities. Therefore, it is of great significance to strengthen the quality management of grease storage.
1. Quality change in grease storage
The grease has the following quality changes after long-term storage:
1) A color change occurs;
2) mixing with mechanical impurities such as lime sand and dust;
3) Mix in moisture or absorb moisture:
4) After long-term storage, the lubricating oil is precipitated and formed into a hard block, and the oil soap is separated to form an acidic substance, and the corrosion is unqualified.
2. Causes of deterioration of grease during storage
Causes of grease deterioration during storage include: external introduction of impurities, moisture; physical or chemical changes in the grease itself.
3. Measures to delay deterioration in grease storage
1) The grease is preferentially stored in the warehouse to reduce the effects of temperature, moisture, dust, etc.;
2) lower the storage temperature;
3) Strengthen the targeted management for the characteristics of different types of grease;
4) Pay attention to sealed storage;
5) Pay attention to the cleaning of the grease removal tool and container;
6) For different users, adopt different packaging forms of large, medium and small;
7) Pay attention to the regular test of stock grease.
two. The main form of failure:
1, oxidative deterioration
2, lipid colloidal structure damage
3, the base oil play
4, fat oil and loss
5, foreign matter mixed in
6, fat aging (hardening, loss of lubrication)
One of the following is invalid:
1, the consistency changes, when it reaches ± (15 ~ 20)%, generally need to change the fat;
2, the drop point change, for the soap base grease, the following is judged as aging failure:
Lithium base grease below 140 ° C, sodium base grease below 120 ° C
Calcium base grease below 50 ° C, composite aluminum below 180 ° C
Composite lithium below 200 ° C, other, changes over ± 20%
3, acid value changes
Grease acid value >3mgKOH/g is invalid
4. Mechanical impurity content, the following is invalid
