Corrosion Protection PVDF-Linings Provide Effective Corrosion Protection
Storage tanks that contain aggressive chemicals must be designed to protect the environment. But how do they protect themselves?
A lot of equipment in the chemical and pharmaceutical industry is exposed to aggressive substances, often over a period of many years. For example bromine, one of the halogens, in combination with moisture is highly corrosive, and it readily attacks steel. Bromine plays an important role in the production of many pharmaceuticals, pesticides and synthetic resins. It is used at the Arkema plant in Marseille to produce the monomer for the bioplastic Rilsan.
The company used to store bromine in lead-lined metal tanks which had a limited service life and required frequent repair. Therefore the tanks were due for replacement in 1984. There were two replacement options: tanks made of glass-coated steel and tanks made of fiberglass reinforced polyester lined with polyvinylidene fluoride (PVDF). One of the reasons why the plastic version was chosen was the lower cost. “The PVDF-lined fiberglass tank cost only about half as much as the glass-lined version,” explained Richard Perrinaud, CPI Business Manager at Arkema. The glass-lined tanks also have a number of other drawbacks. The engineers were concerned about the brittleness of the glass and the risk of leakage, particularly at the weld seams. The steel tanks are also heavier.