Cycle Life: Which Diaphragm to Choose??By afadmin posted 21 Jul, 2011
It is difficult to compare different diaphragms and their life cycles, because, as of now, there are no real test standards. So which one do you go with?
At All-Flo, we really only offer thermoplastic manufactured elastomers. This process allows you to hold very tight tolerances, minimizes any voids, and it allows you to keep a better diaphragm profile. In addition, our Santoprene and Geolast elastomers each have a high shore hardness. Those diaphragms are stiff, which helps them maintain their design profile and gives them a longer cycle life. Geolast and Santoprene also do very well on abrasive services.
A PTFE diaphragm is excellent because it is inert to almost every liquid, but it has several disadvantages: it’s more expensive, has cold temperature limitations (good to only 40 degrees), and only does “fair” on abrasive services.
When deciding on a diaphragm, it makes a difference how much PSI you are pumping: your cycle life at 20PSI will be very different than your cycle life at 120PSI.
Other factors that affect your diaphragm cycle life are: Liquid media used, Liquid discharge pressure, and Suction conditions.
For more information, check out our Technical Resources page (http://all-flo.com/technical-resources.html) to learn more about diaphragm options and materials used and to view performance curves.