SISTO pursues the philosophy ofsupplying diaphragms that can be used as universally as possible.

In practice, this means that we are able to cover a comprehensive spectrum of applications with just a few diaphragm types. A change between the diaphragm types in the same diaphragm size can be carried out easily without having to replace other components.

The design of the diaphragms is specially adapted to the unique SISTO sealing system.

This means that the diaphragms are chambered into the valve bodies and are fully supported from the rear by a spiral spring made of stainless steel.

SISTOAseptiXX – the diaphragms for sterile applications

  • SISTOAseptiXX TFM/EPDM bonded
  • SISTOAseptiXX TFM/EPDM 2-piece

SISTOAseptiXX diaphragms

The SISTOAseptiXX diaphragms come from our own production and are manufactured using high-quality materials.

The diaphragms as a very important component of the diaphragm valves are subject to constantly being further developed by SISTO.

SISTOAseptiXX EPDM diaphragms

SISTOAseptiXX EPDM diaphragms are made of an EPDM rubber that has been specially developed to withstand an operating temperature of up to 140°C.

The diaphragm material complies with FDA requirements, EU1935 and has been tested and certified in accordance with USP guidelines.
The diaphragms are ideally suited for use in “cold applications” such as WFI systems, and thanks to their high ozone resistance, they have also proven extremely successful in CIP and SIP processes.

A fabric integrated into the EPDM rubber enables the diaphragm to be used under vacuum.

SISTOAseptiXX TFM/EPDM bonded diaphragms

The elastomer diaphragms bonded with TFM are made of an FDA compatible EPDM rubber which is firmly bonded to a TFM film featuring improved mechanical properties and lower permeability compared with conventional PTFE.

The material quality of the EPDM and the TFM films complies with the specifications of FDA, EU1935, and USP. The TFM’s excellent chemical and thermal properties make this diaphragm type the first choice for applications with chemically aggressive and abrasive media as well as high temperatures.

SISTOAseptiXX 2-pieceTFM/EPDM diaphragm

With the SISTOAseptiXX 2-piece TFM/EPDM diaphragms, diaphragms with a thicker TFM layer are available. In order to fully utilise the actuation force without affecting the plastic diaphragm’s long service life, the TFM diaphragm is backed by a second diaphragm made of EPDM.

A metal pin embedded in the TFM diaphragm is used to lift the diaphragm and thus to open the valve. In order to prevent damage to the diaphragm during valve closure, the metal pin is fitted to the bonnet assembly by means of a floating nut.

The materials comply with the specifications of FDA, EU1935 and USP. These diaphragms are perfectly suited for applications involving high chemical and thermal stress.

This short video demonstrates the simple exchange of SISTO diaphragms.

Take a look and see for yourself!


All documents downloadable and catalogue available as flipbook (button on the right)

Approvals & Certificates

  • EU1935/FDA

    Diaphragms TFM/EPDM

  • EU1935/FDA

    Diaphragms EPDM (SE1203)

  • USP

    Diaphragms TFM bonded

  • USP

    Diaphragms TFM/EPDM 2-piece

  • USP

    Diaphragmn EPDM (SE1203)

  • ADI

    Declaration by manufacturer