Pharmaceutical Case Study

Pharmaceutical Bioreactor Sealing: Reducing Assembly Rejects from 4% to 0.5%

VMQUSP Class VIPharmaceuticalTight Tolerance

temperature

134°C steam

tolerance

±0.15 mm

reject rate before

reject rate after

<0.5%

Challenge

A bioreactor OEM required USP Class VI silicone O-rings for repeated autoclave cycles (134°C steam), but existing suppliers had inconsistent lot-to-lot dimensions.

Solution

We switched the customer to our VMQ USP Class VI grade with tighter ID tolerances and provided lot-specific dimensional reports.

Result

Assembly reject rate dropped from 4% to under 0.5%, and the OEM qualified us as an approved vendor for all future bioreactor programs.

Details

The bioreactor OEM built stainless steel vessels with precision groove dimensions. Their previous silicone O-ring supplier delivered parts with ID tolerances of ±0.30 mm, which caused intermittent interference fits and assembly delays.

We proposed a USP Class VI platinum-cured silicone with ID tolerance tightened to ±0.15 mm. Every lot was 100% visually inspected and sampled for dimensional verification before shipment.

The customer received lot-specific inspection reports including average ID, CS, and surface quality notes. This documentation was critical for their internal quality audits and FDA supplier qualification process.

After the first three production lots, the customer reported zero dimensional rejections and a reduction in assembly time. We were added to the approved vendor list for all bioreactor platforms.