Stainless Steel Mixing Tanks 102: Sealed Sanitary Mixing Tanks


In our blog post on October 4, Stainless Steel Mixing Tanks 101, we focused on the features of open top tanks for industrial mixing.  Today we follow up that post with Stainless Steel Mixing Tanks 102: Sealed Sanitary Mixing tanks.  The pharmaceutical and biotech industries use these precision-built, high quality tanks for aseptic blending and compounding.

Sanitary sealed mixing tanks usually consist of heavier gauge construction than the open top industrial varieties.  Heavy gauge elliptical heads normally comprise the tank lid and bottom.  Lids are usually hinged with a gasket and hold-down clamps for smaller tanks whereas large vessels consist of a welded top head with access provided by ANSI flange manways.   ASME Pressure Vessel and Boiler code design requirements must be met for applications exceeding 15 psi.  Top mounted mixers generally utilize either a Tri-clamp® gasketed sanitary flange for smaller units or an ANSI standard pipe mounting flange size, also with gasket, for larger ones.

The most common material of construction is 316 or 316L Stainless Steel.  The “L” in 316L designates low carbon.  There are some applications where holding carbon content to below .03% increases resistance to corrosion and aids in the fabrication welding process.  Molybdenum content of 2%-3% is what differentiates the 316 alloys from 304 and provides superior resistance to chemicals and corrosion.  Highly polished and electropolished wetted surfaces, large radii and strict standards for weld and surface defects provide the sanitary and easily cleaned environment for the production of medical compounds and injectable drugs.

Heating jackets, site glasses, dip tube ports, temperature and flow measurement and sanitary diaphragm drains are just a few of the multitude of available accessories for pharmaceutical and sanitary mixing tanks.  Clean in place (CIP) and sanitize in place (SIP) systems are also common in these applications to maintain process sterility before and between batch production.

You can submit the requirements for your tank by completing the INDCO tank data worksheet or contacting customer service or engineering.  We’re always happy to assist you and we can optimize your complete mixing system design with consideration for your material properties, batch size and type of mixing process.