Comparing Chemically Resistant Vacuum Pumps: Chemker 300 vs. Rocker 300C

Choosing a new vacuum pump for your lab requires balancing important considerations including cost/longevity, performance/versatility, and power/size, but it can be simple. This article compares two of Sterlitech’s leading chemically resistant pumps: the Chemker 300 and the Rocker 300C. Both pumps are manufactured by Rocker Scientific Co. and used for widespread applications in filtration technology.

Chemical Resistance and PTFE

A solvent resistant vacuum pump is a critical piece of equipment for labs working with organic extractions, natural products for pharmaceuticals, food safety. Both the Chemker 300 and the Rocker 300C are designed with chemically resistant polytetrafluoroethylene (PTFE) materials, which do not react with corrosive gases, with the exception of highly acidic/alkaline substances. Renowned for its non-stick properties, PTFE is a fluorinated polymer and has high chemical resistance to both aqueous and organic solvents because of the strength of the C-F bonding network [1, 2].

Chemker 300

Features

• Superior chemical resistance
  All wetted parts of Chemker pumps are made of PTFE and FFKM material, making them resistant to most of corrosive gases.
• Oil-free & care-free
  Chemker pumps are driven by diaphragm that needs no lubricant, making it maintenance-free and oil-mist-free.
• Quieter & more stable
  Motor-driven transmission and vibration-proof assembly, making Chemker pumps much quieter and more stable.
• Overheat protection
  All Chemker pumps are equipped with overheat protection device that shuts down when overheated and resumes once cooled down, making the pumps safer and long-lasting.

Rocker 300C

	Model Name	Max flow rate* lpm	Max Vacuum mbar	Noise level dB	Hose barb inch (mm)	Net weight kg
	Rocker 300C	23	99	50	5/16 (8)	4.1

Features

• Diaphragm chamber coated with PTFE
• Diaphragm driven, no lubricant, oil, or oil pollution
• Vibration proof, and low noise
• Thermal protection device initiates automatic shut off if overheated
• CE, RoHS certification and IP 30 protection
• Applications: solvent purification, solid-phase extraction (SPE), vacuum filtration

Comparatively, both pumps are similar in terms of performance specifications, chemical resistance, and scientific applications. Considering all its internal wetted parts are coated with PTFE, versus only the diaphragm of the Rocker 300C, the Chemker 300 may corrode less over time leading to greater longevity and lower repair costs. However, the Chemker 300 offers a stronger vacuum than the Rocker 300C and both models offer an equivalent flow rate.

So how does a lab decide which pump is right for them? If you’re looking for a durable pump designed to endure continuous use and exposure to chemicals, the Chemker 300 is most appropriate. The Rocker 300C is ideal for applications with slightly corroded chemicals or customers with a budget limit. Both the Rocker 300C and Chemker 300 pumps don’t have a significant difference in terms of their space and time-saving features. Both products provide a safe, reliable, and chemically resistant vacuum for a wide range filtration and extraction applications.

References

Chemical resistance PTFE. Polyfluor. Retrieved from https://www.polyfluor.nl/en/chemical-resistance/ptfe/#:~:text=PTFE-,Chemical%20resistance%20PTFE,are%20physical%20and%20also%20reversible 

Breaking harmful bonds. Phys Org. (2008). Retrieved from https://phys.org/news/2008-08-bonds.html