Pure steam is also known as clean steam is defined as saturated steam produced from additive-free water, free from non-condensable gases and dry. It should meet the USP and EU Ph standards for WFI, which specify endotoxins level should be below 0.25 Eu/ml. In simple words, pure steam is generated by the distillation of purified water. Pure steam is used to prevent contamination of vessels, piping distribution systems, and sterile rooms. It is used in place of filtered plant steam to deter contamination by particulate matter, organics and biological loads like pyrogen.
Pure steam or a steam in place system should be used where the steam or the resulting condensate comes into direct or indirect contact with any medical device or pharmaceutical product. For sterilization or sanitization processes in tanks, reactors, supply, and distribution pipe systems, pure steam acts as the ideal heat transfer media. Apart from being of vital importance in the pharmaceutical manufacturing industry, SIP Water Systems have found applications in biotechnology, cosmetics, and food processing industries.
Pure Steam Generator systems are designed to meet the international cGMP requirements as per the FDA and ASME requirements. A pure steam generator (PSG) uses a once-through, forced flow, design to convert the incoming feed water to steam. During the single pass through the water coil, the heat from the hot gases is transferred to the water to convert it to steam. The power feed to produce high quality can be either industrial steam or electricity. Clean steam and pure steam must meet very strict requirements which may vary based on the end application. An essential factor impacting the quality of steam generated is the quality of the source or feed water. To this effect, the source water used to create high-quality steam must be virtually free of impurities. In general, we tend to assume that as steam is boiled from purified water it will be clean or pure, in reality, though things are quite different. The quality of the feed water highly impacts the quality of the steam generated from it. Based on the end application, generated steam must meet strict requirements. For pharmaceutical applications, pure steam needs to be of utmost purity free from all impurities. To this end application, the most common method employed to treat source water is reverse osmosis (RO) water treatment system, which uses fine, semi-permeable membrane to physically remove impurities. This pre-treatment highly reduces the incidence of impurities in feed water and helps achieve pure steam better. When water changes into steam, the gases contained within the water may be dissolved and flow together with the steam. This small traces of contamination need to be contained to maintain the purity levels of steam. Water quality can further be controlled by applying additional treatments like active carbon treatment, UV treatment, thorough removal of chemical and microorganisms.
Pure steam needs to be generated in a high-quality state, and the same quality must be maintained throughout the distribution and application of the steam. This means that apart from ensuring the quality of source water, it is imperative that heating surfaces coming into contact with the water and all valves/pipes used in distributing the steam should be made with materials like stainless-steel to minimize contamination and preserve steam quality. Many clean steam processes aim to isolate the pure steam line by producing it in a separate stainless steel steam generator and supply it with heat from ordinary plant steam.
Pure steam generator systems should be designed and built-in compliance with the Current Good Manufacturing Practices (cGMP) defined by various national and international regulatory bodies like FDA, ASME, and JIS. The steam also needs to pass steam quality tests like non-condensable gases, degrees of superheat and saturation test as per the requirements.
Generating pure steam in a SIP water system involves a thorough understanding of the pure water systems and the current best market practices. TSA Water Systems is a market leader in designing and manufacturing of high purity water systems. Our technical expertise coupled with a problem-solving approach helps us in designing and installing efficient pure steam generators that meet and exceed all national and international standards.
