LJ00577 Excavator Parts for CX700 CX800 CX700B CX800B SH700-5 SH800-5 LBX700X2 Main Relief Valve Pressure Relief Valve

GVO LJ00577 Excavator Parts for CX700 CX800 CX700B CX800B SH700-5 SH800-5 LBX700X2 Main Relief Valve Pressure Relief 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-type main relief valve is a universal distribution valve and main pressure protection valve for six 70-80 ton ultra-large mining excavators: Case CX700, CX800, CX700B, CX800B, and Sumitomo SH700-5, SH800-5. It precisely matches the original valve bore diameter, thread pitch, cartridge stroke, valve core structure, and pressure regulating parameters of these two brands, serving as a crucial overload safety barrier for the hydraulic systems of heavy-duty mining equipment.

The entire valve body is forged from a single piece of high-toughness alloy structural steel, completely eliminating the inherent defects of inferior aftermarket cast iron valve bodies that are prone to cracking under high pressure, suffer from slight deformation under long-term high-frequency loads, and have their sealing surfaces eroded and scratched by high-speed, high-pressure oil.

The valve core, valve sleeve, and valve body—all core pressure-bearing components—undergo three rigorous precision machining processes: full-size integrated precision cutting on a CNC lathe, high-precision centerless grinding of the outer diameter, and diamond ultra-precision honing of the valve sleeve inner bore. The clearance between the valve core and valve sleeve is controlled within micron-level ultra-precision tolerances, minimizing internal oil leakage under high-pressure conditions. This fundamentally solves common industry shortcomings such as pressure regulation drift, insecure locking, and weak or ineffective instantaneous pressure relief under heavy loads.

All pressure-bearing components undergo a dual strengthening treatment: tempering heat treatment followed by surface carburizing and quenching. This results in uniform hardness distribution throughout the valve body, significantly improving resistance to high-frequency hydraulic shocks and fatigue creep. It can stably withstand tens of thousands of reciprocating opening and closing pressure shocks exceeding 35MPa for extended periods without experiencing valve core jamming, external thread stripping or disengagement, or permanent deformation of the sealing ring mounting groove. The outer pressure regulating locking nut adopts a thickened hexagonal reinforced structure, ensuring that the force is even and stable when maintenance personnel use a torque wrench to adjust the system pressure, and preventing issues such as the nut's edges being rounded and slipping, or the set pressure failing to lock and position.

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.