Should thermal expansion valves not be installed on the pipelines in the polymer-based medium storage areas?

The safe design of pipelines for easily polymerizable media such as propylene oxide, styrene, butadiene, etc., is indeed a technical challenge. According to the GB50160-2008 (2018 edition) standards, it is indeed required to implement pressure relief safety measures for closed liquid piping systems that may experience increased pressure due to external factors such as rising temperatures. This is mainly to prevent the pipes from bursting due to overpressure, which could lead to leaks or other serious safety incidents. However, for pipelines carrying easily polymerizable media, extra care is required when designing pressure relief systems, as conventional safety valves and vent valves may increase the risk of polymerization. Blind ends and dead corners tend to become starting points for polymerization, as media can accumulate in these areas and is difficult to remove completely; moreover, conditions such as temperature and catalysts may also facilitate the occurrence of polymerization reactions. To resolve this contradiction, engineers and designers typically take the following measures: 1. Minimize dead zones: Optimize the pipeline design to reduce or eliminate dead ends and corners, allowing the fluid to flow freely without any accumulation of old medium. 2. Use special pressure relief devices: Employ pressure relief devices that are less prone to the formation of dead zones for polymer accumulation, such as pressure relief orifice plates or swing-type pressure relief valves. 3. Regular maintenance and cleaning: Regularly maintain and clean the pipes and pressure relief systems to prevent potential polymerization. 4. Material selection: Choose appropriate materials for pipelines and valves to minimize the impact of catalysts, thereby suppressing polymerization reactions. 5. Process control: Strictly control the operating conditions of the fluid (such as temperature, pressure, flow rate, etc.), and use inhibitors to prevent polymerization. 6. Security assessment and record-keeping: Conduct thorough security assessments, communicate with relevant security regulatory authorities when necessary, and keep technical records for special cases. Actual cases are usually protected as trade secrets, and specific details may not be made public. In such cases, companies work closely with pressure relief valve manufacturers, engineering design firms, and safety assessment agencies to find solutions that meet safety requirements while also reducing the risks associated with polymerization. In some cases, it may be necessary to rely on technological innovation or special design to meet established security requirements while minimizing aggregation risks. It should be noted that the above measures are not applicable universally; specific plans require detailed engineering design and safety assessments based on actual process conditions, equipment parameters, and operational environment. .