Protection valves regulate and safeguard critical automotive systems from pressure fluctuations and contamination. Primarily used in fuel, oil, coolant, and air suspension systems, these valves prevent damage to components like pumps, injectors, and compressors. Common designs include pressure relief, check, and solenoid-operated valves, utilizing spring loading, diaphragm actuation, or electromagnetic control. Materials are selected for compatibility with specific fluids and operating temperatures, typically incorporating NBR, FKM, or PTFE seals. Failure modes generally involve leakage, blockage, or inability to regulate pressure, potentially leading to system malfunction or component failure.