SISTO B, TFM / EPDM-bonded Diaphragm


The TFM’s excellent chemical and thermal properties make this diaphragm type the first choice for applications with chemically aggressive media and high temperatures. This diaphragm type is also recommended for use in media which need to be protected against rubber abrasion and fluids containing oils and greases. As the EPDM rubber is firmly bonded to a TFM film featuring improved mechanical properties and lower permeability compared to conventional PTFE. 

As the rubber is fully covered by the TFM sheet, even mechanical damage to the sheet does not result in cavity formation and therefore to undefined spaces which cannot be cleaned. This composite diaphragm is vacuum-resistant.

Technical information

Sizes DN6 – DN50
Temp. range -30⁰C to 120⁰C (short-term 140⁰C)
Connections Threaded pin
Material EPDM Rubber bonded to TFM film
Certificates USP Class VI, 3.1b, FDA


 Tightening torques chart

DiapphragmMD (Membrane Diameter)
32 46 58 67 82 90 108 132 158 226
EPDM, TFM bonded 1,5 4,5 6 8 12 15 25 30 45 30
PTFE, TFM (2-piece) 2 6 8 10 15 18 28 35 50 35