PB shield oil is a perfluoropolyether oil with a narrow molecular-weight distribution (MWD). It has no flash or fire point, excellent thermo-oxidative stability, good heat transfer capability, uniform volatility, non-toxicity, and zero ozone depletion potential (ODP). It is highly compatible with metals, rubbers, and plastics. Within its service temperature window, PB oil evaporates steadily without oxidation or sludge formation, keeping systems clean. With favorable thermophysical properties, long-term stability, and non-corrosiveness, it is suitable for coating processes across various temperature ranges.