Expert ForumsCorrosion

Topic: Re: Glass tubing

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Glass tubing and piping is sometimes used in the production of pharmaceuticals. It has the advantage of being corrosion resistant to many materials and can tolerate fairly high operating temperatures. Unfortunately, it is difficult to work with (e.g. cutting, bending, etc.), is subject to cracking and breaking, and is hard to make physical connections to other pieces of equipment that typically have flanged or pipe threaded parts. Other disadvantages of glass piping and tubing include its susceptibility to thermal shock and its inherent inability to dissipate a static charge when conveying non-conductive materials.
Stainless steels are widely used in the pharmaceutical industry with the most prevalent types being 304L and 316L. Prior to use, it is often cleaned with an alkaline detergent, rinsed with water, and then passivated with nitric acid, phosphoric acid, or some other, often proprietary, passivating agent. The passivation process facilitates the formation of the thin protective chromium oxide layer that give stainless steel its "stainless" quality.