How do you test grease?
The accepted method for testing grease consistency is the cone penetration test given by ASTM D217 [3]. In this test, a cone is dropped into a cup of grease and the depth of penetration is used as a measurement of consistency. This value of penetration is used to assign a grade to a grease from 000 to 6.
What is Droop point?
(d) Another important parameter is the droop point which determines the temperature at which the product starts oozing out the oil and becomes flattened out.
What is drop point temperature?
Dropping point refers to the temperature at which a grease passes from a semi-solid to a liquid. This is the highest temperature where grease will retain its structure, not the maximum temperature at which it should be used. That number can vary quite a significantly from dropping point.
What is drop point of lubricant?
The dropping point of a lubricating grease is an indication of the heat resistance of the grease and is the temperature at which it passes from a semi-solid to a liquid state under specific test conditions. It is dependent on the type of thickener used and the cohesiveness of the oil and thickener of a grease.
Can we evaluate the service performance of grease by using the dropping point test?
The dropping point itself does not have any bearing on the performance of the grease as it is an in vitro static test. There was a historical rule of thumb that suggested that the upper operating temperature of a conventional soapthickened grease is approximately 2/3 of the dropping point.
What is the grease spot test?
Grease spot test is one of the tests for lipid identification. The working principle is that most lipid or grease are non-volatile due to their high boiling point. Thus, lipid diffracts the light ray so that light can pass from one side of the paper to another side. This gives the phenomenon of “translucent”.
What is slope or current droop?
The droop rate is the downward slope of the top of the output voltage pulse resulting from a flattop current input pulse. Because the current monitor cannot pass DC, whenever the output voltage is non-zero and the current is constant, as during the flat top of the pulse, the voltage decays toward zero exponentially.
How is droop calculated?
In droop, the relationships between real power and frequency and reactive power and voltage are as follows: f = f * − K P ( P − P * ) , V = V * − K Q ( Q − Q * ) . Use of active power-voltage and reactive power-frequency droop, for low-voltage microgrids, is also reported [40].
What is high dropping point in grease?
The dropping point is typically well above the maximum usable temperature of a grease. In summary, dropping point is useful in identifying the thickener type of grease and plays a key role as a quality control test for manufacturing of grease.
What is the flash point of grease?
The flash point (typically 225 degrees C or 440 degrees F for mineral oils) is an indication of the safety hazards of a lubricant with respect to fire and explosion. The flash point and the slightly higher fire point are covered by ASTM D92 and D93.
What is drop point Mettler?
The dropping point is the temperature at which the first drop of a molten substance precipitates from a standardized cup with a defined orifice under controlled testing conditions in a furnace. The drop point is a suddenly occurring event, as the liquefied drop is accelerated by gravity as it escapes the cup.
Which is true about the dropping point of Grease?
Dropping point: Dropping point is an indicator of the heat resistance of grease. As grease temperature rises, penetration increases until the grease liquefies and the desired consistency is lost. Dropping point is the temperature at which a grease becomes fluid enough to drip.
What should the dropping point of soap thickener be?
The results are considered to have only limited significance with respect to service performance of conventional soap thickeners as dropping point is a static test. Above 200 °C, the dropping point has no correlation with the maximum upper operating temperature of the grease.
What’s the significance of the dropping point test?
This test method is useful to assist in identifying the grease as to type and for establishing and maintaining bench marks for quality control. The results are considered to have only limited significance with respect to service performance of conventional soap thickeners as dropping point is a static test.