The Future of Valves and Diaphragms Supply

The author discusses issues related to the supply of soft parts in the biopharma industry.
May 01, 2013
Volume 26, Issue 5

Steve Jones
The biopharmaceutical industry has for a long time suffered inconsistent reliability performance of valves and diaphragms. The cost of a single batch failure can run into the millions of dollars while unplanned production stoppage and contamination investigations consume vast amounts of resources. One cause can be poor maintenance practices by the user, but as lessons are learned and practices improved, the spotlight is shifted. End users increasingly expect valve and diaphragms to deliver more consistent reliability performance through better product design, reliability testing, and improved change control. To enable this much needed transition, the time is right for the bio/pharmaceutical industry and valve and diaphragm suppliers to change the way they do business with each other.


In the past, it has been impossible to predict the life of a diaphragm until tested in the user's full-size commercial system. Although expensive and risky, this has also meant that suppliers are often distanced from the end user's real-world application and reliability experiences. Meanwhile, replacement parts are often supplied through distributors, further distancing suppliers from end-user's performance issues.

Case Study, Bayer HealthCare, San Francisco

Divakar Amin, engineering manager, final product manufacturing at Bayer HealthCare, described the implications of inconsistent diaphragm valve performace to the BioPhorum Operations Group:

"I have experienced two recent incidents involving valve failure during the fill-finish process, causing leakage into a final processing operation. The cost of the lost batch each time was measured in millions of dollars. When we opened each valve up, we found that the diaphragm material had deformed because the material was not suitable for the thermal cycling of the valve.

"We need to ensure that valve manufacturers match the process application to the capabilities of their products. Bulk tanks are exposed to high temperatures during sterilization, peaking at 130 °C. Valve manufacturers tell us that their diaphragm material can withstand 150 °C, but what they don't tell us is how many thermal cycles their material can withstand, especially if the cycle includes low temperature processing. If the polymer is not tested against the full thermal cycle, we have no level of confidence that it's not going to fail and leak.

"It's very important that suppliers perform the reliability testing in the lab and tell us how many thermal cycles the diaphragms will sustain. Without this information I'm left having to change-out my diaphragms every three months because I simply cannot risk losing another batch."


Barak Barnoon, director of process engineering and analytics at Pfizer, raised another example of inconsistent diaphragm valve performance in real-world applications to the BioPhorum Operations Group:

"What is missing currently, is control on their part of their suppliers and their diaphragm raw materials. We have seen impaired performance due both to changes in their sourcing and also in the manufacturing processes of their diaphragm suppliers. There's a big opportunity to increase the level of control and good manufacturing practices."

Divakar cites a further example of inadequate change control:

"If very small changes are made to the diaphragm material, then they can have a big impact on performance. We have experienced a situation where an autoclave valve was replaced with an 'identical' product. Subsequently, the heat-up time of the autoclave went out of its validated range. After extensive investigations we discovered a very minor, undisclosed change to the valve that impacted the process."

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