723-60-22500 723-20-63300 Hydraulic Main Pressure Relief Valve Action Control

Product Specification

723-60-22500 723-20-63300 Hydraulic Main Pressure Relief Valve Action Control Valve PC60-8 PC70-8 PC78US-8 Excavator Parts

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

The GVO cartridge-style main relief valve is a core pressure-protection component specifically engineered for the hydraulic systems of Komatsu’s 7-ton class excavators (PC60-8, PC70-8, and PC78US-8). It directly regulates the system's maximum operating pressure and is a critical, high-wear component that determines digging force, operational smoothness, and the service life of the hydraulic assembly.

The sealing structure and external design have been comprehensively reinforced for durability and seal integrity, specifically addressing the harsh operating conditions typical of these "Dash-8" series compact excavators—such as poor heat dissipation in the enclosed engine compartment, elevated summer oil temperatures, exposure to mud and water splashes, and constant vibration and jolting.

The red identification ring at the top of the valve body utilizes a high-temperature and oil-resistant fluororubber O-ring, capable of withstanding long-term exposure to high-temperature hydraulic oil and thermal cycling without degradation or deformation. A thickened nitrile rubber dust-proof and pressure-resistant seal is installed at the threaded mounting section; this dual-seal configuration effectively prevents external oil leakage and seepage at the valve block interface. Even during prolonged use on muddy sites during the rainy season or in dusty demolition environments, the seals resist hardening, cracking, and extrusion-induced deformation.

The mounting threads are produced using a high-precision rolling process, resulting in a smooth, well-formed thread profile that ensures seamless installation without cross-threading or stripping. The multi-layer locking hex nut at the rear ensures even load distribution, preventing the valve body from loosening or the pressure setting from drifting during travel over rough terrain or high-frequency vibration operations.

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.