Why does the expansion valve frost up? How to diagnose the malfunction
21 Nov,2025
In the practice of refrigeration equipment maintenance, observing the frost formation patterns on the expansion valve has become a core diagnostic tool for technicians to assess the system's operational status. This seemingly simple physical phenomenon actually carries rich insights into how the system is running—when high-temperature, high-pressure liquid refrigerant passes through the expansion valve and undergoes throttling to reduce pressure, the sudden drop in pressure triggers an intense vaporization process that absorbs heat, causing the valve body's surface temperature to plummet. If the ambient temperature remains higher than the valve's surface temperature, frost will begin to form. Different frost patterns serve as the system's "vital signs monitor": for instance, comprehensive frosting across the entire valve body may indicate insufficient refrigerant flow or a clogged filter screen, while localized frost on the outlet side could point to either excessive refrigerant or an abnormal opening of the expansion valve.
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14 Nov,2025
In ensuring the stable operation of refrigeration and industrial equipment, the oil cooling system truly serves as the "cooling core"—overheating of the oil can lead to lubrication failure and accelerated equipment wear, while temperatures that are too low may impair flow efficiency. Choosing the right cooling method directly impacts both the lifespan of your equipment and your operational costs!
Meanwhile, the mainstream oil cooling solutions on the market conveniently focus on four key approaches: water cooling, air cooling, thermosiphon cooling, and spray liquid cooling. Some rely on efficient heat exchange via cooling media, others leverage natural circulation to save energy and simplify maintenance, some offer rapid response to adapt to dynamic operating conditions, and still others eliminate the need for additional media altogether, cutting costs...
But which cooling method delivers higher efficiency? Which one is best suited for handling complex operating scenarios? And which approach strikes the perfect balance between energy savings and operational stability? Today, we’ll tackle these very questions in a comprehensive comparison of the core advantages offered by these four oil cooling techniques—providing you with a clear overview to help you pick the ideal solution!
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14 Nov,2025
As the core safety control point for refrigeration screw compressors, regulating the suction-discharge pressure difference directly impacts both equipment longevity and the stability of the refrigeration system—this article dives deep into the critical safety techniques for pressure differential adjustment, covering everything from identifying abnormal pressure differences to optimizing oil-pressure matching and mastering the ideal timing for intermediate gas replenishment. It’s packed with practical insights that help prevent compressor burnout and leakage issues, making it easy for even beginners to implement right away!
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30 Oct,2025
Liquid ammonia is toxic and highly flammable, and even a minor ammonia leak can pose significant hazards. Additionally, some pressure gauges in the original refrigeration system lack maintenance valves, while individual valves are already rusted, creating potential safety risks. Regular ammonia recovery and maintenance are essential components of proper refrigeration system upkeep.
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Yongyou (Shanghai) Refrigeration Technology Co., Ltd.
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