Relief Valve
0102030405
EX200-5 Main Relief Valve 420-00257 4372038
EX200-5 Main Relief Valve 420-00257 4372038
EX200-5 Main Relief Valve 420-00257 / 4372038
Exclusive to EX200-5 series excavators (part nos.: 420-00257, 4372038), this main relief valve is a core hydraulic protection component from Ningbo Longerfa Hydraulic Co., Ltd.—a professional hydraulic parts manufacturer in Ningbo, China, specializing in cartridge valves, pressure control valves and excavator-specific hydraulic accessories.
Longerfa holds ISO9001/ISO45001 certifications and patents for excavator hydraulic valve technology, equipped with advanced CNC precision machining centers and EX200-5-specific pressure testing platforms. Every 420-00257/4372038 main relief valve undergoes 100% pressure calibration (control precision up to ±0.4MPa) and 36-hour leak-proof verification, fully complying with industry standards and the strict hydraulic system parameters of EX200-5 excavators. It perfectly matches the original equipment’s pressure control logic, ensuring seamless compatibility with both part number specifications.
As the "hydraulic safety gate" of EX200-5, this main relief valve monitors the system’s overall pressure in real time: during high-intensity operations like deep digging, rock breaking or heavy lifting, if pressure exceeds the preset safety threshold, it automatically opens to discharge excess hydraulic oil. This effectively prevents damage to core components such as the main hydraulic pump, multi-way control valve, boom/lifting cylinders and swing motor caused by overpressure. It adopts a high-fatigue-resistance manganese-steel pressure regulating spring and chromium-plated wear-resistant valve core, maintaining stable performance even after 12,000+ pressure cycle operations. Adhering to EX200-5 original installation specs for direct bolt-on replacement, it eliminates the need for complex system debugging—reducing maintenance downtime by 30% on average. Trusted by global aftermarket users, it’s widely applied in construction, mining, infrastructure construction and earthmoving projects where EX200-5 excavators are the main operation equipment.
Adhering to "Quality First, Service First," Longerfa provides a dependable choice for aftermarket maintenance and replacement of EX200-5 excavator hydraulic systems equipped with 420-00257/4372038 main relief valves. It ensures the hydraulic system maintains consistent pressure output, avoids unexpected shutdowns due to pressure abnormalities, and supports long-term safe, efficient operation in harsh working environments (high temperature, dust, vibration).
