Working temperature of stainless steel for medical and chemical equipment

The operating temperature of stainless steel in pharmaceutical and chemical equipment depends primarily on the grade of stainless steel, the equipment structure, the nature of the contact medium, and the actual operating conditions. Common stainless steel equipment used in pharmaceutical production, fine chemical processing, and chemical handling includes reactors, storage tanks, dispensing tanks, heat exchangers, and process piping, each with varying operating temperatures. Commonly used 304 and 316L stainless steels have good heat resistance and maintain good structural stability under many ambient and medium-high temperature conditions, making them widely used in pharmaceutical and chemical equipment manufacturing. Generally, the normal operating temperature of pharmaceutical and chemical equipment may range from room temperature to around 100°C. Some equipment requiring heating, steam sterilization, or high-temperature reactions may operate at 120°C, 150°C, or even higher; the specific range needs to be determined based on the equipment design and process requirements. For example, ordinary pharmaceutical storage tanks typically operate at ambient or lower temperatures, while reactors equipped with jacketed heating systems require controlled heating processes according to the reaction process. It is important to note that while stainless steel can withstand higher temperatures, this does not mean that the entire piece of equipment can operate safely at the same temperature for extended periods. The mechanical properties of materials change with temperature, and gaskets, valves, instruments, and welded parts may have different temperature limitations. Therefore, when determining the operating temperature of equipment, the material's heat resistance, the corrosiveness of the medium, the design pressure, and the overall structure of the equipment should be considered comprehensively, rather than relying solely on the melting point or heat resistance of stainless steel.

 

The operating temperature of stainless steel in pharmaceutical and chemical equipment also directly affects the equipment's corrosion resistance, sealing effect, and service life. When equipment is exposed to high-temperature environments for extended periods, the material's strength, thermal expansion, and the stability of its surface passivation film may change. Simultaneous contact with chloride ions, strong acids, or other corrosive media may increase the risk of pitting corrosion and stress corrosion cracking. Therefore, during the equipment design phase, the design temperature should be determined based on the temperature variation range of the process medium, and reasonable safety conditions should be reserved for heating, cooling, and abnormal operating conditions. For equipment requiring steam heating, hot water circulation, or high-temperature reactions, the temperature resistance of jackets, welds, flanges, and seals should be carefully checked to prevent leaks and structural damage caused by thermal expansion and contraction or rapid temperature changes. During equipment operation, the heating and cooling rates should be controlled according to the process specifications to avoid excessive local temperature differences. Temperature sensors, control valves, and related protective devices should be checked regularly to ensure they are functioning properly. For pressure vessels and pressure vessels, the operating temperature must match the design pressure, allowable material stress, and applicable safety standards; the operating temperature should not be arbitrarily increased. Generally speaking, there is no uniform operating temperature value applicable to all equipment made of stainless steel for pharmaceutical and chemical equipment. The operating temperature should be reasonably controlled based on material certifications, equipment technical documents, design calculations, and actual process conditions to balance equipment safety, corrosion resistance, and long-term performance.