Case Study - Vacuum Pump Failure

Molykote® Synthetic Oil Helps Solve Vacuum Pump Failure

Rotary Vacuum Pump and its Problem

The vacuum pumps that were installed drew hydrochloric acid (HCl) vapors from a reactor vessel that was used to manufacture chemical intermediate products. During the process, some of the acidic vapors would condense from a gas to a liquid and then mix with the oil inside the vacuum chamber. The anti-wear additives in the conventional oil mixed with the HCl vapors, causing a reaction to take place once the oil and HCl vapor came into contact with the process gas in the chamber. This reaction produced small solid particles that deposited onto the casing, which then caused pitting in the casing. Because of the pitting happening in the chamber, the corrosion from the products would then react with the hydrochloric acid, resulting in the formation of corrosive ferric acid.

Solving the Problem with MOLYKOTE®

To address the consistent vacuum pump failures, MOLYKOTE® support staff believed that a specially formulated lubricant would provide better performance. The support staff faced major issues: reducing or eliminating the effects caused by the reaction between the additives in the oil and chemical process gases, and the corrosion and abrasions occurring on the metal vacuum components. The solution the MOLYKOTE® team came up with was a synthetic oil that was specially formulated for the harsh environments in which the vacuum pump was operating. This new synthetic oil was a new line of industrial lubricants, with MOLYKOTE® L-1510 Process Oil being the recommended lubricant for this specific job. 

Traditional solvent-refined oils with zinc-based additive chemistry typically have a higher initial total acid number (TAN) value. In comparison, the MOLYKOTE® brand process gas oils are zinc free, resulting in a lower TAN value. Additionally, the base oil, which contains corrosion, rust, and oxidation preventative additives, is free of sulfur, making the oil a benign product fit for the application. The engineered MOLYKOTE® oils are also more inherently inert and resistant to oxidation and emulsification, increasing the longevity of the lubricant.
 
After MOLYKOTE® L-1510 Process Oil

Once maintenance employees incorporated the MOLYKOTE® L-1510 Process Oil and installed larger oil pumps, the facility saw a 30% decrease in overall operating temperatures. The temperature reduction is believed to be contributed by both the introduction of the MOLYKOTE® lubricant and the installation of the larger oil pump. The major issue that was solved was the elimination of the vacuum pump failure that was caused by corrosive pitting and the interaction between the oil additive and process gas. Introducing MOLYKOTE® L-1510 Process Oil was such a success that the facility ultimately switched all their vacuum pumps to MOLYKOTE®, saving the company nearly $90,000 in maintenance costs.