In 2013 we started producing a PTFE (Teflon) diaphragm for our Tank Valves. PTFE diaphragms are available for 1.0, 1.5, 2.0, and 3.0-inch tank valves. We currently don't have PTFE diaphragms for our Sample Valve or our Weirless Diaphragm Family of valves.
We have spent a great deal of time designing a PTFE diaphragm for use with our valves that meets our high aseptic standards. It is our experience that PTFE is a poor sealing material both because it is not an elastomer and due to the "cold flow" characteristics of the material.
Although we gladly sell our PTFE diaphragms, we recommend that our customers use one of our other diaphragm materials, unless PTFE is the only material that will work for their specific application; for example, if there is exposure to heptane or methyl chloride.
If you are considering PTFE, we suggest that you also consider EPDM Plus, which is EPDM with a Parylene surface treatment that gives some of the positive properties of PTFE with the sealing properties of a rubber (attached is a PDF about Parylene). You might also want to consider steam-resistant Viton A or Viton GF diaphragms.