- WFI tanks, made of stainless steel, are the tried-and-tested tanks for ultra-pure water in the pharmaceutical industry – and therefore indispensable for the production of pharmaceutical products. Water for injection – WFI for short – is one of the most important ingredients in the pharmaceutical industry. It is used primarily for the production of medicines that are administered as injections or infusions. (All vessels and tanks are design as per client requirements adhering to ASME and c’GMP standards)