Varnish film index analysis

Is it to test the paint film tendency index and cleanliness?

If testing is required, we can assist you. We are the authorized distributor of Shell industrial lubricants in the Shaanxi region. If the test results show a high paint film index, we can also carry out treatment using specialized oil purification equipment

We have severe carbon buildup on our bearing shells; we bought equipment for removing paint films last year and are using it now.

I wonder what the effect of the paint film treatment is? I see you are also asking questions about large-scale unit online diagnosis systems. Are you facing any difficulties with this? Want to learn about it*

It is mainly due to carbon buildup on the bearing shells; the ammonia compressor experienced several instances of shutdown triggered by high bearing temperatures. We carried out maintenance after shutting down the machine once, but after 1 month, carbon buildup occurred again, causing the bearing temperatures to rise sharply and leading to another shutdown.

Later, after changing the oil, the carbon buildup disappeared. This year I purchased an oil filter designed to remove the paint film, but I don’t think it had much effect – the paint film index remained low even after changing the oil. In fact, without using that oil filter, the paint film index dropped on its own, while with the air compressor equipped with that paint-film-removing filter, the index hardly changed, and at times it even increased. This might be due to errors in the sampling method or analysis.

Your analysis is reasonable in this regard. First of all, the paint film is a type of polymer made up of high-molecular hydrocarbons; it forms as a result of reactions between the products generated after additives in the oil are consumed and substances resulting from the degradation of the base oil, which then accumulate on the metal surface to create the paint film. Conditions such as high temperature, high pressure, and the properties of the oil itself play a role in this process. If the base oil is of category II, its dissolving capacity is lower compared to that of category I base oils, making it more likely for a paint film to form. Additionally, antioxidants present in the oil also influence this phenomenon – if the antioxidants are of the amine type, they tend to contribute to the formation of paint films. Secondly, it is possible for the carbon deposits to disappear after new oil is added, as the new oil has a certain dissolving capacity. Additionally, as the equipment operates, the temperature of the oil rises, which increases its overall dissolving ability and allows it to dissolve the coating on the metal surface. However, this holds little significance for the equipment, as the coating will re-form and accumulate on the metal surface again once the oil is used up. Therefore, there are several methods to reduce the paint film, such as electrostatic adsorption, resin adsorption, and deep media filtration. The most common methods are electrostatic adsorption and resin adsorption; these can remove the paint film that is dissolved in the oil or accumulated on the metal surface, thereby significantly reducing the paint film index. So it is related to the principle of the oil filter, oil sampling, and the testing capabilities of the testing institutions; a specific analysis is required

It still takes a professional to explain it clearly.:handshake

If there are any further issues later, we can discuss them again