In high-risk environments such as hydrogen energy, chlor-alkali, petrochemicals, and semiconductors, the challenge of equipment maintenance lies not in “repair,” but in safety isolation, medium replacement, and cross-system coordination. These four articles cover hydrogen compressors, electrolysers, graphite heat exchangers, and chlorine compressors, providing a comprehensive guide from maintenance through decommissioning.
The section on hydrogen compressors points out that maintenance and decommissioning are the highest-risk stages of the lifecycle. All work must first undergo nitrogen purging and pass inspection. The chlor-alkali industry requires coordinated efforts involving chlorine compressors, HCl furnaces, and graphite heat exchangers; hydrogen refueling stations must comply with GB 50516, with nitrogen purity ≥99.2% and oxygen ≤0.5%; the semiconductor industry requires cleanrooms and a leakage rate of 10⁻⁹ Pa·m³/s; and hydrogen metallurgy focuses on dry gas seals and hydrogen embrittlement. Recommended for equipment and safety personnel across multiple industries.
The most valuable aspect of the “Electrolyzer” section is the “three-tier maintenance logic” (https://www.dongshengjs.com/news/A-Comprehensive-Guide-to-Electrolyzer-Maintenance.html): daily cleaning and monitoring, scheduled overhauls, and condition-based cell replacement. The article lists replacement cycles by technology—ALK, PEM, chlor-alkali, molten salt, electroplating, and wastewater treatment: ALK separators 5–8 years; PEM MEAs 3–5 years; chlor-alkali ion exchange membranes approximately 3 years; and prebaked aluminum anodes 20–30 days. It also covers EIS diagnostics, start-up and shutdown restrictions, and the recycling of used components. Suitable for operators in hydrogen production, chlor-alkali, electroplating, and environmental protection.
The Graphite Heat Exchanger section focuses on chlor-alkali and HCl synthesis, providing a systematic comparison of maintenance procedures for block-and-hole and shell-and-tube designs: block removal/core extraction, waterjet cleaning, PT/UT/ECT testing, pore/tube plugging, block/bundle replacement, and hydrostatic and air tightness tests. Key reminders include that graphite is vulnerable to impact and must not come into contact with steel wire ropes; seals should be made of fluorinated elastomers or flexible graphite; air tightness tests are mandatory; and maintenance cycles typically range from 2.5 to 4 years. Recommended for maintenance, procurement, and spare parts management personnel.
Chlorine Compressor Section(https://www.dongshengjs.com/news/The-Most-Comprehensive-Guide-to-Chlorine-Compressor-Servicing-and-Maintenance.html): Service is categorized into four levels: routine maintenance, major overhaul, disassembly, and rebuild. The safety baseline requires purging with dry nitrogen until residual chlorine is <1 ppm, and obtaining a hot work permit. For routine monitoring, focus on sulfuric acid concentration ≥93%, chlorine-containing water, shaft seals, and vibration; the overhaul cycle is 16,000–20,000 hours, shortened to 12,000 hours if water quality is poor; rebuild requirements include dynamic balancing to ISO G1.0 and a 30-minute air tightness test at 0.5 bar with a pressure drop ≤0.02 bar. Suitable for chlor-alkali plants and contractors.
The four articles share a common thread: isolate first, purge next, then test; work may proceed only upon passing inspection. Differences lie in industry standards, maintenance intervals, and operational details. They provide actionable checklists, terminology, and decision-making logic, making them worth keeping as reference materials. If you are responsible for hydrogen, chlorine, electrolysis, or graphite equipment, we recommend reading each article thoroughly.
