Chemglass G3/4 Blind Stopper for Bioreactor

The Chemglass Life Sciences G3/4 Blind Stopper is a heavy-duty sealing component engineered for the headplates of benchtop and pilot-scale bioreactors that utilize G3/4 (BSPP) threaded ports. Manufactured from high-grade 316L Stainless Steel with a smooth electropolished finish, this plug is designed to meet the strict sanitary requirements of cGMP bioprocessing. It is fully capable of withstanding the extreme thermal cycling of autoclave sterilization and the corrosive environment of acidic cell culture media.

This stopper is essential for maintaining the integrity of a "closed system" when specific headplate ports are not in use. While the G3/4 port is typically reserved for larger assemblies—such as exhaust gas condensers, foam sensors, or baffle cages—there are specific process runs where these components may be unnecessary. In such cases, this blind stopper screws into the port, compressing a dedicated O-ring to create a pressure-rated, hermetic seal. This prevents environmental contamination and ensures the vessel can hold the positive pressure required for aeration and sterility.