4469304 4469298 4659820 4613559 Excavator ZX450 ZX870-5G ZX670-5G EX1200-6 Main Relief Valve Pressure Relief Valve Safety Valve

4469304 4469298 4659820 4613559 Excavator ZX450 ZX870-5G ZX670-5G EX1200-6 Main Relief Valve Pressure Relief Valve Safety 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 core pressure protection assembly in the hydraulic systems of many Hitachi large-tonnage mining excavators. It is precisely compatible with the older ZX450 heavy-duty model, the ZX670-5G and ZX870-5G (National III emission standard) mining excavators, and the main mounting position of the EX1200-6 ultra-large mining excavator's distribution valve. It conforms 1:1 to the original factory valve bore size, thread specifications, and pressure regulating structure, serving as the main safety gate for the entire hydraulic circuit.

The entire valve core, valve sleeve, and valve body undergo three core precision machining processes: full-size precision turning on a CNC lathe, high-precision centerless grinding of the outer diameter, and diamond honing of the valve sleeve inner bore. The clearance between the valve core and valve sleeve is controlled within micron-level precision tolerances, minimizing internal oil leakage under high pressure and completely resolving industry-wide problems such as pressure regulation drift, unstable locking pressure, and weak instantaneous pressure relief under heavy loads. All pressure-bearing components undergo a dual strengthening process of tempering heat treatment and surface carburizing and quenching, resulting in balanced overall hardness and sufficient impact resistance and toughness. They can withstand high-frequency repeated opening and closing pressure impacts exceeding 35MPa for extended periods without issues such as valve core jamming, external thread stripping, or permanent deformation of the sealing ring mounting groove.

The outer pressure regulating locking nut features a thickened hexagonal reinforced structure, ensuring even force distribution when adjusting system pressure with a wrench, preventing slippage at the nut's edges and failure to lock the pressure. The multi-hole valve head at the front end employs a streamlined oil passage design, resulting in extremely low oil flow resistance and preventing additional hydraulic shocks and abnormal oil temperature rises caused by turbulence.

It is equipped with high- and low-temperature resistant fluororubber high-pressure O-rings, resistant to hydraulic oil corrosion, high-temperature aging, and low-temperature hardening in winter. Even under conditions of prolonged full-load operation in 5G models with soaring oil temperatures and extreme day-night temperature differences in open-pit mines, its sealing performance remains stable, eliminating problems such as oil leakage, dripping, and internal pressure leakage from the valve body.

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.