Comparing the Chemical Resistance of Chemker 300 and Rocker 300C Vacuum Pumps

June 04, 2019

Chemker 300 and Rocker 300C are among Sterlitech’s popular vacuum pumps offering excellent chemical resistance. Both pumps are resistant to acid, alkali, and organic solutions, which allows for a wide variety of microbiology testing applications.

Polytetrafluoroethylene (PTFE) serves as their primary protection against harsh chemicals; however, there designs incorporate PTFE differently. The diaphragm and chamber of Rocker 300C are PTFE-coated, built with a valve made of a chemical resistant SS316 stainless steel. In contrast, all parts of Chemker 300 that can be exposed to chemicals are made of PTFE.

While the PTFE coating of Rocker 300C is made to be durable, it can wear off over time exposing the underlying material, especially if used with abrasive substances. Also, its stainless-steel valve does not offer the same level of resistance as PTFE, especially with halides, and strong acids and bases (1).

Chemker 300C avoids all these potential issues by having its parts completely made of PTFE—there is less risk for wearing off and all wetted parts are made of a single material providing consistent protection. With these design advantages, Chemker 300 over extended period time will perform better than Rocker 300C.

So, would it be better to own a Chemker 300 over Rocker 300C?

Well, it still depends on the type of chemicals you handle in your laboratory, how often you expose these devices to such chemicals, and how much you are willing to invest in such equipment, at least initially.

Rocker 300C is initially available at a lower cost, but the additional cost for the repairs and the cost of the operational delay that may ensue can offset or even be higher than the cost of Chemker 300.

This could be said if your laboratory handles corrosive chemicals frequently. Otherwise, Rocker 300C would suffice for applications exposed to corrosive chemicals with the device properly operated and maintained. Generally, it is vital that you understand the context of your laboratory before choosing between these vacuum pumps.

For more information about Sterlitech chemical resistant vacuum pumps, you can visit our Vacuum Pumps page. Alternatively, you can call us at 1-877-544-4420 so we could help choose the right product for you.

Reference:

[1] Chemical Compatibility Database. Cole-Parmer. Retrieved from https://www.coleparmer.com/Chemical-Resistance