723-46-40500 7234640500 Excavator PC290-8K PC240-8K PC490LC-10 PC240LC-10 Pressure Relief Valve Pressure Compensation Valve

723-46-40500 7234640500 Excavator PC290-8K PC240-8K PC490LC-10 PC240LC-10 Pressure Relief Valve Pressure Compensation Valve

Product Description

The GVO excavator relief valve, compatible with Hitachi excavators, is a key pressure control valve in the hydraulic system. It regulates hydraulic pressure, releases overload pressure, protects core hydraulic components such as the main valve and hydraulic pump, and ensures stable operation of the entire machine.

This relief valve is precision-machined from high-quality steel and undergoes overall quenching treatment. Equipped with oil-resistant and high-pressure-resistant seals, it boasts excellent sealing performance, impact resistance, and wear resistance. Suitable for the high-pressure hydraulic conditions of excavators, it effectively prevents internal leakage, pressure loss, operational instability, and vibration.

Product Introduction

This GVO cartridge-style main relief valve is a critical pressure safety control component for the hydraulic systems of Komatsu’s new-generation (8K and 10 series) medium-to-large excavators. It precisely fits four mainstream models: the medium-duty PC240-8K and PC290-8K (upgraded 8th-generation versions), the 10th-generation PC240LC-10 (extended undercarriage), and the heavy-duty mining model PC490LC-10. It serves dual functions: acting as the main relief valve for the control valve block to lock the system's operating pressure, and functioning as an overload protection valve to buffer instantaneous high-pressure shocks caused by digging stalls, sudden swing stops, or hill climbing. It is a key replacement part for resolving issues such as insufficient power and pressure loss in these new electronic-injection Komatsu models.

The valve body undergoes a dual heat-treatment process—quenching and tempering followed by high-frequency surface hardening—significantly enhancing both structural rigidity and surface wear resistance. The outer diameter is precision-ground and polished using a centerless grinding process to achieve a mirror-like finish; this withstands long-term erosion and scratching from metal debris or dust in the hydraulic fluid, preventing bore scoring that would otherwise lead to persistent internal pressure loss.

The internal spool and valve seat sealing interface utilize deep-hole honing and ultra-precision lapping processes, maintaining micron-level clearances for sensitive pressure sensing and millisecond-level response times. When the hydraulic system's instantaneous load pressure exceeds the OEM safety setting, the spool opens immediately to relieve pressure and stabilize the system; conversely, it reseats tightly to lock in pressure the moment the load drops. This fundamentally resolves a series of common, persistent issues associated with relief valve aging and failure in Komatsu 8K and 10 series models—problems that often plague owners, such as weak digging force, bucket pressure loss under heavy loads, boom drift (sagging), stuttering during arm retraction, shock and vibration during swing start/stop, insufficient pressure during hill climbing, engine stalling or RPM drops, abnormal hydraulic oil temperature rises, and poor coordination during compound movements.

Packaging & Shipping

We use high-strength, environmentally friendly paper export packaging, which is reinforced, cushioned, and moisture-proof, suitable for long-distance international logistics transportation, and meets cross-border freight and environmental protection standards. International transportation adopts formal cross-border logistics, with full tracking of logistics information and supporting customs clearance documents to ensure smooth customs clearance and timely delivery of goods overseas.

Company Introduction

The GVO brand is a manufacturer of hydraulic components. We mainly produce the most comprehensive range of pilot pumps, gear pumps, relief valves, hydraulic pumps, electrical components, hydraulic parts, engine assemblies, traveling assemblies, rotating assemblies, distribution valves, and other components.

We are factory direct sellers without any middlemen profiting from price differences. The quality is definitely the best for you because we are the ones who produce them. We cannot tarnish our reputation. The prices are also the most favorable for you. There is a stable delivery speed.

We value every customer and provide you with the best service. We offer pre-sale, in-sale, and after-sale guarantees. Any problems will definitely be resolved for you. We are always available to serve you.