Q. My application involves a peristaltic pump with silicone tubing running through it and a different, heat-sealable tubing material before and after the pump section. Recently, an operator installed the wrong section of tubing in a pump, resulting in lost API, equipment replacement, and hours of extra work. How can we avoid this kind of mix-up in the future?

A. One solution is to label different tubing sections for their intended use. Another approach is to use one tubing material, namely a thermoplastic elastomer (TPE), for the entire line. TPE is often used before and after the pump section where sealability is needed. TPE properties vary depending on the formulation and the process used to make the polymer, and in the past some formulations could not be used inside the pump. Today, however, there are versions of TPE that work very well in peristaltic pumps and can be used for the entire line. 

A possible concern is using steam sterilization with TPE because steam tends to deform tubing.  Some steam cycles can be used as long as they have a lower temperature and time exposure cycle and care is taken in positioning the tubing in the autoclave. A user who intends to sterilize with steam should validate their sterilization cycle with the intended use of a TPE tubing. Gamma radiation sterilization poses no problems with either silicone or TPE.

Using a single tubing eliminates fitting connections and tie wraps, along with their possible leaks and entrapment issues. Having a single material also simplifies the overall design, reduces inventory expenses, shortens assembly time and labor, and eliminates the possibility of installing the wrong tubing section in the pump.

—John Stover, product technical director, New Age Industries.

If you have a problem with your equipment or process, an industry expert may have the solution. Please send your question to Jennifer Markarian, editor of Equipment and Processing Report, and we may be able to provide an answer in a future issue. All questions will remain anonymous.